MENU
The Electronic Scholarly Publishing Project: Providing world-wide, free access to classic scientific papers and other scholarly materials, since 1993.
More About: ESP | OUR CONTENT | THIS WEBSITE | WHAT'S NEW | WHAT'S HOT
ESP: PubMed Auto Bibliography 31 May 2025 at 01:39 Created:
Biofilm
Wikipedia: Biofilm A biofilm is any group of microorganisms in which cells stick to each other and often also to a surface. These adherent cells become embedded within a slimy extracellular matrix that is composed of extracellular polymeric substances (EPS). The EPS components are produced by the cells within the biofilm and are typically a polymeric conglomeration of extracellular DNA, proteins, and polysaccharides. Because they have three-dimensional structure and represent a community lifestyle for microorganisms, biofilms are frequently described metaphorically as cities for microbes. Biofilms may form on living or non-living surfaces and can be prevalent in natural, industrial and hospital settings. The microbial cells growing in a biofilm are physiologically distinct from planktonic cells of the same organism, which, by contrast, are single-cells that may float or swim in a liquid medium. Biofilms can be present on the teeth of most animals as dental plaque, where they may cause tooth decay and gum disease. Microbes form a biofilm in response to many factors, which may include cellular recognition of specific or non-specific attachment sites on a surface, nutritional cues, or in some cases, by exposure of planktonic cells to sub-inhibitory concentrations of antibiotics. When a cell switches to the biofilm mode of growth, it undergoes a phenotypic shift in behavior in which large suites of genes are differentially regulated.
Created with PubMed® Query: ( biofilm[title] NOT 28392838[PMID] NOT 31293528[PMID] NOT 29372251[PMID] ) NOT pmcbook NOT ispreviousversion
Citations The Papers (from PubMed®)
RevDate: 2025-05-30
Knowledge, Attitudes, and Practices of the Saudi Arabian Population Regarding Contaminated Banknotes: Implications for Infectious Disease Transmission and Analyzing the Biofilm in Wallet as a Reservoir.
The Canadian journal of infectious diseases & medical microbiology = Journal canadien des maladies infectieuses et de la microbiologie medicale, 2025:4611971.
Introduction: Contaminated paper currency may serve as a potential source for multidrug-resistant pathogens, posing risks not only to individuals who handle cash but also to public health. This study aimed to evaluate the knowledge, attitudes, and practices (KAP), and microbial contamination of paper currency and biofilm formation in the wallet as a reservoir of contamination in Saudi Arabia (KSA). Methods: Data were collected through an online survey assessing the KAP of the Saudi population regarding the use of contaminated notes across various provinces from February to April 2018. The analysis was conducted using EPI INFO V7 software. Microorganisms were isolated and identified from paper and plastic currency collected from slaughterhouses, gas stations, and hospital cafeterias. The MicroScan WalkAway system was utilized for confirmation and antimicrobial resistance (AMR) testing, while scanning electron microscopy (SEM) was employed to visualize biofilms present in wallets. Results: Among the 1415 adult Saudi citizens surveyed, 75% lacked awareness about contaminated currency. Over 50% reported not washing their hands after handling contaminated notes, with 78% of those being male. Fifteen different microbial species were isolated from contaminated notes, including Staphylococcus and fecal coliforms. Multidrug-resistant Staphylococcus and Enterobacter were detected in nearly all paper notes, while extended-spectrum beta-lactamase (ESBL) E. coli was found only in 50-riyal notes. Plastic notes showed no bacterial contamination. SEM images of the interior surfaces of wallets revealed the presence of extracellular polymeric substances (EPSs) in biofilms, along with cocci-shaped bacteria. Conclusion: To mitigate health risks, it is recommended that paper notes be replaced with plastic currency, and efforts should be made to raise awareness among the Saudi population regarding the dangers posed by contaminated notes.
Additional Links: PMID-40444033
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40444033,
year = {2025},
author = {Almogbel, M and Huq, M and Almogbel, M and Almatroudi, A and Allemailem, KS},
title = {Knowledge, Attitudes, and Practices of the Saudi Arabian Population Regarding Contaminated Banknotes: Implications for Infectious Disease Transmission and Analyzing the Biofilm in Wallet as a Reservoir.},
journal = {The Canadian journal of infectious diseases & medical microbiology = Journal canadien des maladies infectieuses et de la microbiologie medicale},
volume = {2025},
number = {},
pages = {4611971},
pmid = {40444033},
issn = {1712-9532},
abstract = {Introduction: Contaminated paper currency may serve as a potential source for multidrug-resistant pathogens, posing risks not only to individuals who handle cash but also to public health. This study aimed to evaluate the knowledge, attitudes, and practices (KAP), and microbial contamination of paper currency and biofilm formation in the wallet as a reservoir of contamination in Saudi Arabia (KSA). Methods: Data were collected through an online survey assessing the KAP of the Saudi population regarding the use of contaminated notes across various provinces from February to April 2018. The analysis was conducted using EPI INFO V7 software. Microorganisms were isolated and identified from paper and plastic currency collected from slaughterhouses, gas stations, and hospital cafeterias. The MicroScan WalkAway system was utilized for confirmation and antimicrobial resistance (AMR) testing, while scanning electron microscopy (SEM) was employed to visualize biofilms present in wallets. Results: Among the 1415 adult Saudi citizens surveyed, 75% lacked awareness about contaminated currency. Over 50% reported not washing their hands after handling contaminated notes, with 78% of those being male. Fifteen different microbial species were isolated from contaminated notes, including Staphylococcus and fecal coliforms. Multidrug-resistant Staphylococcus and Enterobacter were detected in nearly all paper notes, while extended-spectrum beta-lactamase (ESBL) E. coli was found only in 50-riyal notes. Plastic notes showed no bacterial contamination. SEM images of the interior surfaces of wallets revealed the presence of extracellular polymeric substances (EPSs) in biofilms, along with cocci-shaped bacteria. Conclusion: To mitigate health risks, it is recommended that paper notes be replaced with plastic currency, and efforts should be made to raise awareness among the Saudi population regarding the dangers posed by contaminated notes.},
}
RevDate: 2025-05-29
CmpDate: 2025-05-29
Biochemical and functional properties of vesicles from planktonic and biofilm phenotypes of Limosilactobacillus reuteri DSM 17938.
Scientific reports, 15(1):18889.
Limosilactobacillus reuteri DSM 17938 is among the world's most studied probiotic strains and has been shown to provide several health benefits for the host. We have previously shown that the cell-free supernatant of L. reuteri DSM 17938 possesses antimicrobial activity and contains several bioactive compounds. Furthermore, the strain was shown to be a biofilm producer that releases both planktonic and biofilm Membrane Vesicles (MVs). In this study, membrane vesicles isolated from planktonic (pMVs) and biofilm (bMVs) phenotypes were comparatively investigated for their toxicity, ability to kill cancer as well as non-cancer cell lines and modulate phagocytosis in murine macrophages. Neither pMVs nor bMVs showed any in vivo toxicity in a Galleria mellonella model, and weakly affected cancer and noncancerous cell viability after both short- and long-term treatments. However, they were able to affect phagocytosis in lipopolysaccharide challenged RAW 264.7 macrophages, suggesting possible immunomodulatory properties. NMR-based metabolomic analysis of pMVs and bMVs identified and quantified engulfed compounds, mainly organic acids and amino acids, with lactate being the most abundant molecule in both vesicle types. bMVs contained higher concentrations of all measured metabolites compared to pMVs. Proteomic analysis of pMVs and bMVs described equivalent protein cargos, emphasizing quantitative compositional differences that presumably reflect the physiological state of each parent bacterial phenotype. Through the assignment of molecules possibly acting as mediators of immune/inflammatory responses in the host and/or modulating known beneficial effects of L. reuteri, important signaling functions of these vesicles were suggested. Finally, storage stability of MVs up to four weeks was established.
Additional Links: PMID-40442239
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40442239,
year = {2025},
author = {Marinacci, B and D'Ambrosio, C and Vitale, I and Di Sotto, A and Cairone, F and Spano, M and Carradori, S and Scaloni, A and Gullì, M and Puca, V and Francati, S and Matuozzo, M and Lundberg, LE and Grompone, G and Roos, S and Grande, R},
title = {Biochemical and functional properties of vesicles from planktonic and biofilm phenotypes of Limosilactobacillus reuteri DSM 17938.},
journal = {Scientific reports},
volume = {15},
number = {1},
pages = {18889},
pmid = {40442239},
issn = {2045-2322},
support = {CN00000022//Agritech National Research Center within the European Union NextGenerationEU program (the National Recovery and Resilience Plan, mission 4, component 2, investment 1.4 - D.D. 1032 del 17/06/2022)/ ; },
mesh = {Animals ; *Biofilms/growth & development ; Mice ; Phagocytosis ; *Limosilactobacillus reuteri/physiology/metabolism ; RAW 264.7 Cells ; Macrophages ; Phenotype ; *Plankton/metabolism ; *Extracellular Vesicles/metabolism ; Probiotics ; Humans ; },
abstract = {Limosilactobacillus reuteri DSM 17938 is among the world's most studied probiotic strains and has been shown to provide several health benefits for the host. We have previously shown that the cell-free supernatant of L. reuteri DSM 17938 possesses antimicrobial activity and contains several bioactive compounds. Furthermore, the strain was shown to be a biofilm producer that releases both planktonic and biofilm Membrane Vesicles (MVs). In this study, membrane vesicles isolated from planktonic (pMVs) and biofilm (bMVs) phenotypes were comparatively investigated for their toxicity, ability to kill cancer as well as non-cancer cell lines and modulate phagocytosis in murine macrophages. Neither pMVs nor bMVs showed any in vivo toxicity in a Galleria mellonella model, and weakly affected cancer and noncancerous cell viability after both short- and long-term treatments. However, they were able to affect phagocytosis in lipopolysaccharide challenged RAW 264.7 macrophages, suggesting possible immunomodulatory properties. NMR-based metabolomic analysis of pMVs and bMVs identified and quantified engulfed compounds, mainly organic acids and amino acids, with lactate being the most abundant molecule in both vesicle types. bMVs contained higher concentrations of all measured metabolites compared to pMVs. Proteomic analysis of pMVs and bMVs described equivalent protein cargos, emphasizing quantitative compositional differences that presumably reflect the physiological state of each parent bacterial phenotype. Through the assignment of molecules possibly acting as mediators of immune/inflammatory responses in the host and/or modulating known beneficial effects of L. reuteri, important signaling functions of these vesicles were suggested. Finally, storage stability of MVs up to four weeks was established.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
Animals
*Biofilms/growth & development
Mice
Phagocytosis
*Limosilactobacillus reuteri/physiology/metabolism
RAW 264.7 Cells
Macrophages
Phenotype
*Plankton/metabolism
*Extracellular Vesicles/metabolism
Probiotics
Humans
RevDate: 2025-05-29
Three-dimensional buckling model reveals the evolution of energy-driven biofilm wrinkle morphologies.
Canadian journal of microbiology [Epub ahead of print].
On solid substrates, biofilms develop rich wrinkle morphologies during its growth. Based on the thin film buckling theory, we established a local three-dimensional biofilm/substrate buckling model, and explored the effects of mechanical forces, elastic modulus of the substrate and biofilm thickness on the wrinkle morphology. We simulated the wrinkle evolution in various patterns of Bacillus subtilis biofilm growing on agar substrates with different stiffness and found that the biofilm wrinkling process is the process of internal energy release. The stiffness of the substrate changes the wrinkling time of the biofilm; The biofilm wrinkle morphology (patterns II, III, IV) Uinternal and Uinternal/U0 decrease with nutrient consumption, and the biofilm evolves towards lower energy consumption. In the early stages of biofilm growth (patterns I, II, and III), the harder the agar substrate, the larger the Ufriction and Ufriction/U0, which is less conducive to biofilm expansion.
Additional Links: PMID-40440731
Publisher:
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40440731,
year = {2025},
author = {Wu, J and Li, J and Wang, J and Wang, X},
title = {Three-dimensional buckling model reveals the evolution of energy-driven biofilm wrinkle morphologies.},
journal = {Canadian journal of microbiology},
volume = {},
number = {},
pages = {},
doi = {10.1139/cjm-2024-0196},
pmid = {40440731},
issn = {1480-3275},
abstract = {On solid substrates, biofilms develop rich wrinkle morphologies during its growth. Based on the thin film buckling theory, we established a local three-dimensional biofilm/substrate buckling model, and explored the effects of mechanical forces, elastic modulus of the substrate and biofilm thickness on the wrinkle morphology. We simulated the wrinkle evolution in various patterns of Bacillus subtilis biofilm growing on agar substrates with different stiffness and found that the biofilm wrinkling process is the process of internal energy release. The stiffness of the substrate changes the wrinkling time of the biofilm; The biofilm wrinkle morphology (patterns II, III, IV) Uinternal and Uinternal/U0 decrease with nutrient consumption, and the biofilm evolves towards lower energy consumption. In the early stages of biofilm growth (patterns I, II, and III), the harder the agar substrate, the larger the Ufriction and Ufriction/U0, which is less conducive to biofilm expansion.},
}
RevDate: 2025-05-29
The two-component system CpxAR controls biofilm formation by directly regulating the T3SS needle tip protein EseB in Edwardsiella piscicida.
Applied and environmental microbiology [Epub ahead of print].
The type III secretion system (T3SS) translocon protein EseB (needle tip protein) forms filamentous appendages on the surface of Edwardsiella piscicida to facilitate autoaggregation and biofilm formation. By contrast, another T3SS translocon protein EseC inhibits biofilm formation by sequestering EseC's chaperone EseE, which also functions as a positive regulator of the escC-eseE operon, in which EseB is encoded. The two-component system (TCS) EsrAB and the regulator EsrC tightly and positively regulate the T3SS in E. piscicida. The TCS CpxAR provides an adaptive response to external environmental changes. In this study, we have shown that disruption of the histidine kinase CpxA (sensor) instead of CpxR (response regulator) significantly reduces biofilm formation in E. piscicida. CpxR is negatively regulated by CpxA, and significant amounts of CpxR accumulate in E. piscicida in the absence of CpxA. CpxR, together with EsrB and EsrC, directly binds the promoter of the cpxR-cpxA operon to promote CpxR transcription and expression. The elevated phosphorylated CpxR (CpxR-P) binds to the promoter of the escC-eseE operon to repress eseB transcription and expression, while EseE, EsrB, and EsrC bind directly to the same promoter to promote EseB transcription and expression. E. piscicida is an enteric pathogen that senses microbiota-derived indole in the gut lumen. EseB filament-mediated biofilm formation in E. piscicida is inversely proportional to exogenous indole. Together, CpxR inhibits while EsrB, EsrC, and EseE stimulate transcription and expression of the escC-eseE operon, thereby coordinately controlling EseB filament-mediated biofilm formation in E. piscicida in response to environmental stimuli.IMPORTANCEEdwardsiella piscicida is primarily an enteric pathogen of fish and can form a biofilm to resist the lethal effects of host or antimicrobial agents. The assembly of filamentous appendages on the bacterial surface, mediated by the type III secretion system (T3SS) needle tip protein EseB, promotes bacterial-bacterial interactions and biofilm formation when E. piscicida is cultured in Dulbecco's modified Eagle's medium (DMEM). In this study, we have shown that the histidine kinase CpxA regulates biofilm formation in E. piscicida by negatively regulating its response regulator CpxR. Binding to the promoter of the escC-eseE operon, CpxR negatively regulates, whereas EsrB, EsrC, and EseE positively regulate the escC-eseE operon, of which EseB is encoded, coordinately regulating biofilm formation in E. piscicida.
Additional Links: PMID-40439422
Publisher:
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40439422,
year = {2025},
author = {Zhang, SY and Sun, SS and Liu, LY and Sivaranjan, T and Nie, P and Xie, HX},
title = {The two-component system CpxAR controls biofilm formation by directly regulating the T3SS needle tip protein EseB in Edwardsiella piscicida.},
journal = {Applied and environmental microbiology},
volume = {},
number = {},
pages = {e0226424},
doi = {10.1128/aem.02264-24},
pmid = {40439422},
issn = {1098-5336},
abstract = {The type III secretion system (T3SS) translocon protein EseB (needle tip protein) forms filamentous appendages on the surface of Edwardsiella piscicida to facilitate autoaggregation and biofilm formation. By contrast, another T3SS translocon protein EseC inhibits biofilm formation by sequestering EseC's chaperone EseE, which also functions as a positive regulator of the escC-eseE operon, in which EseB is encoded. The two-component system (TCS) EsrAB and the regulator EsrC tightly and positively regulate the T3SS in E. piscicida. The TCS CpxAR provides an adaptive response to external environmental changes. In this study, we have shown that disruption of the histidine kinase CpxA (sensor) instead of CpxR (response regulator) significantly reduces biofilm formation in E. piscicida. CpxR is negatively regulated by CpxA, and significant amounts of CpxR accumulate in E. piscicida in the absence of CpxA. CpxR, together with EsrB and EsrC, directly binds the promoter of the cpxR-cpxA operon to promote CpxR transcription and expression. The elevated phosphorylated CpxR (CpxR-P) binds to the promoter of the escC-eseE operon to repress eseB transcription and expression, while EseE, EsrB, and EsrC bind directly to the same promoter to promote EseB transcription and expression. E. piscicida is an enteric pathogen that senses microbiota-derived indole in the gut lumen. EseB filament-mediated biofilm formation in E. piscicida is inversely proportional to exogenous indole. Together, CpxR inhibits while EsrB, EsrC, and EseE stimulate transcription and expression of the escC-eseE operon, thereby coordinately controlling EseB filament-mediated biofilm formation in E. piscicida in response to environmental stimuli.IMPORTANCEEdwardsiella piscicida is primarily an enteric pathogen of fish and can form a biofilm to resist the lethal effects of host or antimicrobial agents. The assembly of filamentous appendages on the bacterial surface, mediated by the type III secretion system (T3SS) needle tip protein EseB, promotes bacterial-bacterial interactions and biofilm formation when E. piscicida is cultured in Dulbecco's modified Eagle's medium (DMEM). In this study, we have shown that the histidine kinase CpxA regulates biofilm formation in E. piscicida by negatively regulating its response regulator CpxR. Binding to the promoter of the escC-eseE operon, CpxR negatively regulates, whereas EsrB, EsrC, and EseE positively regulate the escC-eseE operon, of which EseB is encoded, coordinately regulating biofilm formation in E. piscicida.},
}
RevDate: 2025-05-29
Marine microbial enzymes as potential antibiofilm agents: expanding the arsenal of bioactive agents targeting biofilm-forming microorganisms.
Critical reviews in microbiology [Epub ahead of print].
Biofilms are one of the most successful modes of life in the biosphere. In these assemblages, bacteria usually display higher resistance to environmental stressors, thus making their removal through the use of conventional approaches significantly more difficult. Currently, biofilms are one of the major challenges in healthcare settings, often resulting in higher mortality and morbidity rates. Therefore, seeking alternative approaches to manage biofilm-related infections is important. In the last decades, marine microbiomes have been increasingly harnessed as sources of molecules with wide-ranging applications in both the biomedical and pharmaceutical sectors. This review focuses on enzymes as potential antibiofilm agents, more specifically those derived from marine prokaryotes. An overview of the recent findings regarding four main classes of biofilm-disrupting enzymes and their respective marine microbial producers, namely nucleases, dextranases, alginate lyases, and peptidases is provided. Key biochemical and activity-related features from the current literature are presented to showcase the potential of these biocatalysts for biofilm control and prevention. Future research directions are also discussed, highlighting factors and strategies for successful prospecting of antibiofilm enzymes from marine microbiomes. By offering a snapshot of this infant but promising field, this review evidences the marine environment as a fruitful biocatalytic reservoirs of antibiofilm agents.
Additional Links: PMID-40439000
Publisher:
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40439000,
year = {2025},
author = {Canellas, ALB and Dias, GR and Lopes, IR and Freitas-Silva, J and Dobson, ADW and Laport, MS and de Oliveira, BFR},
title = {Marine microbial enzymes as potential antibiofilm agents: expanding the arsenal of bioactive agents targeting biofilm-forming microorganisms.},
journal = {Critical reviews in microbiology},
volume = {},
number = {},
pages = {1-18},
doi = {10.1080/1040841X.2025.2510247},
pmid = {40439000},
issn = {1549-7828},
abstract = {Biofilms are one of the most successful modes of life in the biosphere. In these assemblages, bacteria usually display higher resistance to environmental stressors, thus making their removal through the use of conventional approaches significantly more difficult. Currently, biofilms are one of the major challenges in healthcare settings, often resulting in higher mortality and morbidity rates. Therefore, seeking alternative approaches to manage biofilm-related infections is important. In the last decades, marine microbiomes have been increasingly harnessed as sources of molecules with wide-ranging applications in both the biomedical and pharmaceutical sectors. This review focuses on enzymes as potential antibiofilm agents, more specifically those derived from marine prokaryotes. An overview of the recent findings regarding four main classes of biofilm-disrupting enzymes and their respective marine microbial producers, namely nucleases, dextranases, alginate lyases, and peptidases is provided. Key biochemical and activity-related features from the current literature are presented to showcase the potential of these biocatalysts for biofilm control and prevention. Future research directions are also discussed, highlighting factors and strategies for successful prospecting of antibiofilm enzymes from marine microbiomes. By offering a snapshot of this infant but promising field, this review evidences the marine environment as a fruitful biocatalytic reservoirs of antibiofilm agents.},
}
RevDate: 2025-05-29
The Dual Role of the Medicinal Mushroom Fomitopsis pinicola in Inhibiting Biofilm and Reducing Antibiotic Resistance of Methicillin-Resistant Staphylococcus aureus.
Food science & nutrition, 13(6):e70355.
This study investigates the antimicrobial, antibiofilm, and anti-quorum sensing activity of Fomitopsis pinicola against methicillin-resistant Staphylococcus aureus (MRSA) strains and its potential to improve the efficacy of conventional antibiotics and exert selective cytotoxic effects on cancer cells. Ethanolic extracts of F. pinicola were analyzed for antibacterial activity by MIC and time-kill assays. Synergistic interactions with antibiotics were quantified using checkerboard assays. Antibiofilm activity was analyzed on polystyrene and stainless-steel surfaces. Anti-quorum sensing activity was determined by the inhibition of violacein in Chromobacterium violaceum. Efflux pump inhibition was assessed by the accumulation of the ethidium bromide. The down-regulation of virulence genes (agrA, hla) was measured by qRT-PCR (quantitative real-time reverse-transcription PCR). FT-IR (Fourier transform infrared spectroscopy) spectroscopy characterized the bioactive compounds, and the cytotoxicity assays on HT-29 colon cancer and Vero cells evaluated selective toxicity. The extract showed strong antibacterial effects with a MIC of 312.5 μg/mL and concentration-dependent bactericidal activity. Synergistic interactions with antibiotics led to FIC indices ≤ 0.5. The extract significantly inhibited biofilm formation and eradicated already formed biofilms. Sub-MIC concentrations reduced quorum sensing by 85.01%, inhibited efflux pump activity, and down-regulated virulence-associated genes. FT-IR analysis confirmed the presence of triterpenoids and terpenoids. The extract displayed selective cytotoxicity on HT-29 cancer cells, showing strong inhibition, while normal Vero cells were spared. These results emphasize the potential of F. pinicola as a robust candidate for antimicrobial therapeutics, especially against biofilm-associated and multidrug-resistant pathogens, as well as a selective anticancer agent.
Additional Links: PMID-40438095
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40438095,
year = {2025},
author = {Karaca, B and Kyalo Kilonzo, N and Korkmaz, Ş and Onar, O and Yıldırım, Ö and Çöleri Cihan, A},
title = {The Dual Role of the Medicinal Mushroom Fomitopsis pinicola in Inhibiting Biofilm and Reducing Antibiotic Resistance of Methicillin-Resistant Staphylococcus aureus.},
journal = {Food science & nutrition},
volume = {13},
number = {6},
pages = {e70355},
pmid = {40438095},
issn = {2048-7177},
abstract = {This study investigates the antimicrobial, antibiofilm, and anti-quorum sensing activity of Fomitopsis pinicola against methicillin-resistant Staphylococcus aureus (MRSA) strains and its potential to improve the efficacy of conventional antibiotics and exert selective cytotoxic effects on cancer cells. Ethanolic extracts of F. pinicola were analyzed for antibacterial activity by MIC and time-kill assays. Synergistic interactions with antibiotics were quantified using checkerboard assays. Antibiofilm activity was analyzed on polystyrene and stainless-steel surfaces. Anti-quorum sensing activity was determined by the inhibition of violacein in Chromobacterium violaceum. Efflux pump inhibition was assessed by the accumulation of the ethidium bromide. The down-regulation of virulence genes (agrA, hla) was measured by qRT-PCR (quantitative real-time reverse-transcription PCR). FT-IR (Fourier transform infrared spectroscopy) spectroscopy characterized the bioactive compounds, and the cytotoxicity assays on HT-29 colon cancer and Vero cells evaluated selective toxicity. The extract showed strong antibacterial effects with a MIC of 312.5 μg/mL and concentration-dependent bactericidal activity. Synergistic interactions with antibiotics led to FIC indices ≤ 0.5. The extract significantly inhibited biofilm formation and eradicated already formed biofilms. Sub-MIC concentrations reduced quorum sensing by 85.01%, inhibited efflux pump activity, and down-regulated virulence-associated genes. FT-IR analysis confirmed the presence of triterpenoids and terpenoids. The extract displayed selective cytotoxicity on HT-29 cancer cells, showing strong inhibition, while normal Vero cells were spared. These results emphasize the potential of F. pinicola as a robust candidate for antimicrobial therapeutics, especially against biofilm-associated and multidrug-resistant pathogens, as well as a selective anticancer agent.},
}
RevDate: 2025-05-28
CmpDate: 2025-05-28
Sensitivity analysis of operational parameters on excess sludge reduction in moving bed biofilm reactor (MBBR) system upgraded to integrated fixed film activated sludge (IFAS) process based on GPS-X environment.
Water environment research : a research publication of the Water Environment Federation, 97(6):e70084.
This study investigated the modeling of sludge reduction and process optimization in a moving bed biofilm reactor treating sewage upgraded to an integrated fixed film activated sludge process using GPS-X8 simulation. The sensitivity analysis of dissolved oxygen concentration, recycle activated sludge, media portion, and biofilm thickness on sludge generation was simulated. The results revealed that an increase in dissolved oxygen concentration from 2.7 to 5 mg/L resulted in an 89% reduction in sludge. Likewise, increasing the recycle activated sludge ratio from 50% to 200% decreased the sludge production from 1000 to 90 g/L, leading to a 91% reduction in sludge. Moreover, it was observed that sludge was highly eliminated from 910 to 400 g/L, as the media volume increased from 45 to 55%. Furthermore, a sludge reduction from 1000 to 400 g/L was achieved when the biofilm thickness increased from 1 to 5 mm, respectively. Finally, the process was optimized with minimum sludge production of 400 g/day and preferable system performance attributed to TSS, BOD, COD, NO3, PO4 [-3]-P, and NH4 effluent concentrations of 14, 5, 10, 21, 1.25, and 0.4 mg/L, respectively. This concludes that sludge reduction can be achieved by operating the moving bed biofilm reactor as an integrated fixed film activated sludge process. PRACTITIONER POINTS: The MBBR system was upgraded to IFAS system by return activated sludge (RAS) to the MBBR reactor. Excess sludge can be efficiently reduced by operating the system as IFAS process. The IFAS process was successfully modeled using GPS-X8 simulation. Sensitive operational parameters effects: DO concentration, RAS, media portion, and biofilm thickness on sludge production have been evaluated. Sludge reduction (56% to 91%) is achieved at 5 mg/L DO concentration, 200% RAS, 55% media portion, and 5 mm biofilm thickness.
Additional Links: PMID-40436738
Publisher:
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40436738,
year = {2025},
author = {Khudhair, DN and Zwain, HM and Siadatmousavi, SM and Hosseinzadeh, M},
title = {Sensitivity analysis of operational parameters on excess sludge reduction in moving bed biofilm reactor (MBBR) system upgraded to integrated fixed film activated sludge (IFAS) process based on GPS-X environment.},
journal = {Water environment research : a research publication of the Water Environment Federation},
volume = {97},
number = {6},
pages = {e70084},
doi = {10.1002/wer.70084},
pmid = {40436738},
issn = {1554-7531},
mesh = {*Bioreactors ; *Biofilms ; *Sewage ; *Waste Disposal, Fluid/methods ; Geographic Information Systems ; },
abstract = {This study investigated the modeling of sludge reduction and process optimization in a moving bed biofilm reactor treating sewage upgraded to an integrated fixed film activated sludge process using GPS-X8 simulation. The sensitivity analysis of dissolved oxygen concentration, recycle activated sludge, media portion, and biofilm thickness on sludge generation was simulated. The results revealed that an increase in dissolved oxygen concentration from 2.7 to 5 mg/L resulted in an 89% reduction in sludge. Likewise, increasing the recycle activated sludge ratio from 50% to 200% decreased the sludge production from 1000 to 90 g/L, leading to a 91% reduction in sludge. Moreover, it was observed that sludge was highly eliminated from 910 to 400 g/L, as the media volume increased from 45 to 55%. Furthermore, a sludge reduction from 1000 to 400 g/L was achieved when the biofilm thickness increased from 1 to 5 mm, respectively. Finally, the process was optimized with minimum sludge production of 400 g/day and preferable system performance attributed to TSS, BOD, COD, NO3, PO4 [-3]-P, and NH4 effluent concentrations of 14, 5, 10, 21, 1.25, and 0.4 mg/L, respectively. This concludes that sludge reduction can be achieved by operating the moving bed biofilm reactor as an integrated fixed film activated sludge process. PRACTITIONER POINTS: The MBBR system was upgraded to IFAS system by return activated sludge (RAS) to the MBBR reactor. Excess sludge can be efficiently reduced by operating the system as IFAS process. The IFAS process was successfully modeled using GPS-X8 simulation. Sensitive operational parameters effects: DO concentration, RAS, media portion, and biofilm thickness on sludge production have been evaluated. Sludge reduction (56% to 91%) is achieved at 5 mg/L DO concentration, 200% RAS, 55% media portion, and 5 mm biofilm thickness.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
*Bioreactors
*Biofilms
*Sewage
*Waste Disposal, Fluid/methods
Geographic Information Systems
RevDate: 2025-05-28
CmpDate: 2025-05-28
Inhibitory effects of the cell-free supernatants of Faecalibacterium prausnitzii on biofilm formation of Listeria monocytogenes.
Food research international (Ottawa, Ont.), 213:116588.
This study aimed to investigate the effects of the cell-free supernatant (CFS) of Faecalibacterium prausnitzii on biofilm formation and potential modes of action. Biofilm formed by Listeria monocytogenes poses a threat to food industry due to its resistance to disinfectants and its capacity to contaminate foods. Certain probiotics have been reported to inhibit L. monocytogenes biofilm formation. F. prausnitzii has recently emerged as a promising next generation beneficial microbe. However, its interaction with L. monocytogenes biofilm formation remains unexplored. The anti-biofilm activity of F. prausnitzii CFS was first evaluated. Then biofilm structure and components were examined as well as bacterial parameters associated with biofilm formation. Finally, the anti-biofilm efficacy of CFS in the real food system was determined. CFS significantly reduced biofilm mass by 97.3 % and decreased metabolic activity within the biofilm by 87.2 %. Fluorescence microscopy and Raman spectroscopy analyses demonstrated that CFS disrupted both the structural integrity and biochemical components of the biofilm. Furthermore, CFS of F. prausnitzii diminished cellular motility, reduced surface hydrophobicity, inhibited self-aggregation, and decreased biofilm formation on various food substrates and surfaces. RT-qPCR analysis demonstrated that CFS markedly suppressed the expression of genes associated with biofilm formation in L. monocytogenes. This study provides the first report of the anti-biofilm activity of F. prausnitzii CFS, enhancing our understanding of the beneficial properties of these bacteria. These findings indicate that CFS from F. prausnitzii might be developed as an alternative strategy to reduce L. monocytogenes biofilm and its associated contamination in food systems.
Additional Links: PMID-40436568
Publisher:
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40436568,
year = {2025},
author = {Wang, A and Teng, Y and Jin, T and Zhu, W and Jia, J and Xia, X},
title = {Inhibitory effects of the cell-free supernatants of Faecalibacterium prausnitzii on biofilm formation of Listeria monocytogenes.},
journal = {Food research international (Ottawa, Ont.)},
volume = {213},
number = {},
pages = {116588},
doi = {10.1016/j.foodres.2025.116588},
pmid = {40436568},
issn = {1873-7145},
mesh = {*Biofilms/drug effects/growth & development ; *Listeria monocytogenes/drug effects/physiology/growth & development/genetics ; *Faecalibacterium prausnitzii/metabolism ; Food Microbiology ; *Probiotics/pharmacology ; },
abstract = {This study aimed to investigate the effects of the cell-free supernatant (CFS) of Faecalibacterium prausnitzii on biofilm formation and potential modes of action. Biofilm formed by Listeria monocytogenes poses a threat to food industry due to its resistance to disinfectants and its capacity to contaminate foods. Certain probiotics have been reported to inhibit L. monocytogenes biofilm formation. F. prausnitzii has recently emerged as a promising next generation beneficial microbe. However, its interaction with L. monocytogenes biofilm formation remains unexplored. The anti-biofilm activity of F. prausnitzii CFS was first evaluated. Then biofilm structure and components were examined as well as bacterial parameters associated with biofilm formation. Finally, the anti-biofilm efficacy of CFS in the real food system was determined. CFS significantly reduced biofilm mass by 97.3 % and decreased metabolic activity within the biofilm by 87.2 %. Fluorescence microscopy and Raman spectroscopy analyses demonstrated that CFS disrupted both the structural integrity and biochemical components of the biofilm. Furthermore, CFS of F. prausnitzii diminished cellular motility, reduced surface hydrophobicity, inhibited self-aggregation, and decreased biofilm formation on various food substrates and surfaces. RT-qPCR analysis demonstrated that CFS markedly suppressed the expression of genes associated with biofilm formation in L. monocytogenes. This study provides the first report of the anti-biofilm activity of F. prausnitzii CFS, enhancing our understanding of the beneficial properties of these bacteria. These findings indicate that CFS from F. prausnitzii might be developed as an alternative strategy to reduce L. monocytogenes biofilm and its associated contamination in food systems.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
*Biofilms/drug effects/growth & development
*Listeria monocytogenes/drug effects/physiology/growth & development/genetics
*Faecalibacterium prausnitzii/metabolism
Food Microbiology
*Probiotics/pharmacology
RevDate: 2025-05-28
Effect of light intensity on performance, microbial community and metabolic pathway of algal-bacterial symbiosis in sequencing batch biofilm reactor treating mariculture wastewater.
Bioresource technology pii:S0960-8524(25)00692-3 [Epub ahead of print].
An algal-bacterial symbiosis (ABS) system was constructed in a sequencing batch biofilm reactor for mariculture wastewater treatment, and its performance, microbial community and metabolic pathway were analyzed under different light intensities. The ammonia oxidation rate and nitrate reduction rate under 7000 Lux light intensity were higher than other light intensities. Functional microorganisms including Nitrosomonas, Nitrospira, Alterinioella, and Chlorella vulgaris were enriched under 7000 Lux. Metabolism was the primary functional pathway based on Kyoto Encyclopedia of Genes and Genomes. Tricarboxylic acid (TCA) cycle, nitrogen metabolism and photosynthesis pathways belonging to Metabolism were promoted under 7000 Lux light intensity. The enhancement of light intensity promoted the algal photosynthesis, TCA cycle, electron generation, and nitrogen transformation. The TCA cycle and electron generation offered energy and electron donors for nitrogen transformation. This research provides fundamental knowledge to select optimal light intensity for ABS system treating mariculture wastewater.
Additional Links: PMID-40436322
Publisher:
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40436322,
year = {2025},
author = {Wang, Q and Chu, G and Gao, C and Tian, T and Zhang, W and Chen, W and Gao, M},
title = {Effect of light intensity on performance, microbial community and metabolic pathway of algal-bacterial symbiosis in sequencing batch biofilm reactor treating mariculture wastewater.},
journal = {Bioresource technology},
volume = {},
number = {},
pages = {132726},
doi = {10.1016/j.biortech.2025.132726},
pmid = {40436322},
issn = {1873-2976},
abstract = {An algal-bacterial symbiosis (ABS) system was constructed in a sequencing batch biofilm reactor for mariculture wastewater treatment, and its performance, microbial community and metabolic pathway were analyzed under different light intensities. The ammonia oxidation rate and nitrate reduction rate under 7000 Lux light intensity were higher than other light intensities. Functional microorganisms including Nitrosomonas, Nitrospira, Alterinioella, and Chlorella vulgaris were enriched under 7000 Lux. Metabolism was the primary functional pathway based on Kyoto Encyclopedia of Genes and Genomes. Tricarboxylic acid (TCA) cycle, nitrogen metabolism and photosynthesis pathways belonging to Metabolism were promoted under 7000 Lux light intensity. The enhancement of light intensity promoted the algal photosynthesis, TCA cycle, electron generation, and nitrogen transformation. The TCA cycle and electron generation offered energy and electron donors for nitrogen transformation. This research provides fundamental knowledge to select optimal light intensity for ABS system treating mariculture wastewater.},
}
RevDate: 2025-05-28
Mature biofilm-sensitive lysozyme-grafted Bi-guanidine backbone porphyrin nanorods for deep penetration and double phototherapy.
Biomaterials, 323:123431 pii:S0142-9612(25)00350-3 [Epub ahead of print].
The efficacy of antibacterial therapy was largely vitiated because of the shield of bacteria by the intricate architecture of biofilms. For emerging phototherapy strategies like photothermal therapy (PTT) and photodynamic therapy (PDT), dense biofilms can substantially impede the permeation of photo-agents, ultimately compromising the thermal conductivity and reactive oxygen species (ROS) diffusion. To address these challenges, we have proposed a biofilm-sensitive MT nanorod with dual phototherapy, based on the ordered directional assembly of photosensitizer meso-tetra(4-carboxyphenyl) porphine (TCPP) molecules by metformin hydrochloride (MET) as functional backbone. The formed MT nanorod avoids the uncontrollable aggregation of TCPP, producing pleased water-solubility with efficient fluorescent emission and allowing simultaneous PTT-PDT effects under a single laser. The grafted MT-LYZ by conjugation of lysozyme (LYZ) to MT nanorods can be used for acidic environment guided deep biofilm penetration and LYZ-assisted dual phototherapy for effective elimination of mature biofilm, with MT-LYZ acquires adaptive conversion from negative to positive charges in biofilm. Because of effective bacterial ablation within biofilms and gene regulation in bacterial quorum, MT-LYZ was successfully utilized for the treatment of deep-seated MRSA biofilm infections with minimized side effects, which promotes the repair of the MRSA biofilm infected wounds in mice and displays anti-inflammatory features, providing an alternative approach for effectively combating biofilm infections.
Additional Links: PMID-40435816
Publisher:
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40435816,
year = {2025},
author = {Yao, W and Wang, T and Sun, W and Zhang, X and Xiong, H and Yin, J and Liu, L and Liu, X and Wang, X and Jiang, H},
title = {Mature biofilm-sensitive lysozyme-grafted Bi-guanidine backbone porphyrin nanorods for deep penetration and double phototherapy.},
journal = {Biomaterials},
volume = {323},
number = {},
pages = {123431},
doi = {10.1016/j.biomaterials.2025.123431},
pmid = {40435816},
issn = {1878-5905},
abstract = {The efficacy of antibacterial therapy was largely vitiated because of the shield of bacteria by the intricate architecture of biofilms. For emerging phototherapy strategies like photothermal therapy (PTT) and photodynamic therapy (PDT), dense biofilms can substantially impede the permeation of photo-agents, ultimately compromising the thermal conductivity and reactive oxygen species (ROS) diffusion. To address these challenges, we have proposed a biofilm-sensitive MT nanorod with dual phototherapy, based on the ordered directional assembly of photosensitizer meso-tetra(4-carboxyphenyl) porphine (TCPP) molecules by metformin hydrochloride (MET) as functional backbone. The formed MT nanorod avoids the uncontrollable aggregation of TCPP, producing pleased water-solubility with efficient fluorescent emission and allowing simultaneous PTT-PDT effects under a single laser. The grafted MT-LYZ by conjugation of lysozyme (LYZ) to MT nanorods can be used for acidic environment guided deep biofilm penetration and LYZ-assisted dual phototherapy for effective elimination of mature biofilm, with MT-LYZ acquires adaptive conversion from negative to positive charges in biofilm. Because of effective bacterial ablation within biofilms and gene regulation in bacterial quorum, MT-LYZ was successfully utilized for the treatment of deep-seated MRSA biofilm infections with minimized side effects, which promotes the repair of the MRSA biofilm infected wounds in mice and displays anti-inflammatory features, providing an alternative approach for effectively combating biofilm infections.},
}
RevDate: 2025-05-28
Enhanced deep denitrification for high-salinity wastewater treatment by constructing biofilm-based technology.
Journal of environmental management, 388:125980 pii:S0301-4797(25)01956-5 [Epub ahead of print].
Biofilm-based technologies, particularly the sequencing biofilm batch reactor (SBBR), have emerged as a robust solution for high-salinity wastewater treatment. However, there were contradiction in the performance on high-salinity wastewater treatment of suspended carrier and fibrous carrier in SBBR. Additionally, it was seldom that biofilm formation, recovery capability, and pollutant removal for different carriers were systematically studied during the gradually increasing salinity condition. Therefore, two SBBR reactors were operated with two different shapes of carriers (suspended carrier and fibrous carrier) in treating high-salinity wastewater with gradually increasing salinity from 0.5 % to 2 % in this study. The results showed that under increasing salinity, the removal capacity of fibrous carrier group (R2) and suspended carrier group (R1) for COD and TIN far surpasses that of the conventional activated sludge group (R3). Under 2 % salinity, the removal rates of COD in R1 and R2 achieved 83.9 % and 84.8 %, and those of TIN in R1 and R2 reached 81.7 % and 81.0 %, respectively. Meanwhile, under increasing salinity conditions, the R2 group demonstrated a significantly higher COD and NH4[+]-N removal speed per single operational cycle compared to R1 group. The primary reason was that the excessive secretion of EPS and increased protein-like components in the R2 group enhanced its biofilm adaptability under high-salinity conditions, thereby facilitating the enrichment of salt-tolerant functional microbial communities (e.g., Pseudofulvimonas). Finally, when applied to actual high-salinity pickle wastewater, the fibrous carrier demonstrated superior performance (e.g., COD removal efficiency of 93 %, TIN removal efficiency of 95 %) due to its efficient partial nitrification and denitrification, and lower energy consumption costs. Overall, these findings highlight the potential of new biofilm-based technology as a promising solution for high-salinity wastewater treatment.
Additional Links: PMID-40435808
Publisher:
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40435808,
year = {2025},
author = {Ding, K and Yang, S and Hu, H and Li, Z and Duan, H and Chen, X and Liu, Y and Sheng, G},
title = {Enhanced deep denitrification for high-salinity wastewater treatment by constructing biofilm-based technology.},
journal = {Journal of environmental management},
volume = {388},
number = {},
pages = {125980},
doi = {10.1016/j.jenvman.2025.125980},
pmid = {40435808},
issn = {1095-8630},
abstract = {Biofilm-based technologies, particularly the sequencing biofilm batch reactor (SBBR), have emerged as a robust solution for high-salinity wastewater treatment. However, there were contradiction in the performance on high-salinity wastewater treatment of suspended carrier and fibrous carrier in SBBR. Additionally, it was seldom that biofilm formation, recovery capability, and pollutant removal for different carriers were systematically studied during the gradually increasing salinity condition. Therefore, two SBBR reactors were operated with two different shapes of carriers (suspended carrier and fibrous carrier) in treating high-salinity wastewater with gradually increasing salinity from 0.5 % to 2 % in this study. The results showed that under increasing salinity, the removal capacity of fibrous carrier group (R2) and suspended carrier group (R1) for COD and TIN far surpasses that of the conventional activated sludge group (R3). Under 2 % salinity, the removal rates of COD in R1 and R2 achieved 83.9 % and 84.8 %, and those of TIN in R1 and R2 reached 81.7 % and 81.0 %, respectively. Meanwhile, under increasing salinity conditions, the R2 group demonstrated a significantly higher COD and NH4[+]-N removal speed per single operational cycle compared to R1 group. The primary reason was that the excessive secretion of EPS and increased protein-like components in the R2 group enhanced its biofilm adaptability under high-salinity conditions, thereby facilitating the enrichment of salt-tolerant functional microbial communities (e.g., Pseudofulvimonas). Finally, when applied to actual high-salinity pickle wastewater, the fibrous carrier demonstrated superior performance (e.g., COD removal efficiency of 93 %, TIN removal efficiency of 95 %) due to its efficient partial nitrification and denitrification, and lower energy consumption costs. Overall, these findings highlight the potential of new biofilm-based technology as a promising solution for high-salinity wastewater treatment.},
}
RevDate: 2025-05-28
CmpDate: 2025-05-28
In vitro investigation on nanosilver-Moringa oleifera of optical characteristics, photoantimicrobial activity, and damage profile against Candida albicans biofilm.
Brazilian journal of biology = Revista brasleira de biologia, 85:e282822 pii:S1519-69842025000100209.
Nanosilver material has been widely applied in the cosmetics, medical, ceramics, electronics, energy renewable and other industries. In the medical sector, nanosilver has been recombined with medicinal plant extracts that contain antimicrobial and antioxidant properties. Nanosilver has also been used in photodynamic Inactivation or other terms photoantimicrobial as a photosensitizer agent. Photoinactivation is a light-based therapy technique to kill pathogenic microbial or fungal cells. This research investigates the ability of biosynthesized nanosilver using Moringa leaf extract (AgNPs-MO) to inhibit Candida albicans biofilm growth. The aspects observed were optical characteristics, photoantimicrobial activity and changes in biofilm cell morphology through the results of Scanning Electron Microscope (SEM) observations. The research results showed that the optics characteristics of nanosilver-moringa oleifera experienced a shift in the absorption wavelength compared to individual investigations of each nanoparticle and Moringa leaf extract. Single nanoparticles did not show significant wave peaks, Moringa leaf extract with λmax1=425 nm and λmax2=635 nm, while the AgNPs-MO spectrum produced λmax=440 nm. Photoantimicrobial activity for cell viability tests, the treatment with the maximum inhibitory effect was the AgNPs-MO combination LED group, 75% (red LED) and 80% (blue LED), respectively. Another indicator of photoantimicrobial activity is the malondialdehyde level produced in each Candida albicans cell due to lipid oxidation. The maximum malondialdehyde level was 1.7 nmol/mL. SEM observations show severe morphological damage was visual for the AgNPs-MO combination LED treatment group. This research is new in developing and utilizing therapeutic approaches that can potentially treat infectious diseases and overcome their severity in the future. The selection of materials and products for AgNPs-MO can be an innovative alternative used in the medical field.
Additional Links: PMID-40435064
Publisher:
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40435064,
year = {2025},
author = {Astuty, SD and Tabaika, PM and Imelda, I and Astuti, SD and Endarko, E and Arifin, NF},
title = {In vitro investigation on nanosilver-Moringa oleifera of optical characteristics, photoantimicrobial activity, and damage profile against Candida albicans biofilm.},
journal = {Brazilian journal of biology = Revista brasleira de biologia},
volume = {85},
number = {},
pages = {e282822},
doi = {10.1590/1519-6984.282822},
pmid = {40435064},
issn = {1678-4375},
mesh = {*Candida albicans/drug effects ; *Biofilms/drug effects/growth & development ; *Silver/pharmacology/chemistry ; *Plant Extracts/pharmacology/chemistry ; *Moringa oleifera/chemistry ; *Metal Nanoparticles/chemistry ; Microscopy, Electron, Scanning ; *Antifungal Agents/pharmacology ; Microbial Sensitivity Tests ; *Photosensitizing Agents/pharmacology ; Plant Leaves/chemistry ; },
abstract = {Nanosilver material has been widely applied in the cosmetics, medical, ceramics, electronics, energy renewable and other industries. In the medical sector, nanosilver has been recombined with medicinal plant extracts that contain antimicrobial and antioxidant properties. Nanosilver has also been used in photodynamic Inactivation or other terms photoantimicrobial as a photosensitizer agent. Photoinactivation is a light-based therapy technique to kill pathogenic microbial or fungal cells. This research investigates the ability of biosynthesized nanosilver using Moringa leaf extract (AgNPs-MO) to inhibit Candida albicans biofilm growth. The aspects observed were optical characteristics, photoantimicrobial activity and changes in biofilm cell morphology through the results of Scanning Electron Microscope (SEM) observations. The research results showed that the optics characteristics of nanosilver-moringa oleifera experienced a shift in the absorption wavelength compared to individual investigations of each nanoparticle and Moringa leaf extract. Single nanoparticles did not show significant wave peaks, Moringa leaf extract with λmax1=425 nm and λmax2=635 nm, while the AgNPs-MO spectrum produced λmax=440 nm. Photoantimicrobial activity for cell viability tests, the treatment with the maximum inhibitory effect was the AgNPs-MO combination LED group, 75% (red LED) and 80% (blue LED), respectively. Another indicator of photoantimicrobial activity is the malondialdehyde level produced in each Candida albicans cell due to lipid oxidation. The maximum malondialdehyde level was 1.7 nmol/mL. SEM observations show severe morphological damage was visual for the AgNPs-MO combination LED treatment group. This research is new in developing and utilizing therapeutic approaches that can potentially treat infectious diseases and overcome their severity in the future. The selection of materials and products for AgNPs-MO can be an innovative alternative used in the medical field.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
*Candida albicans/drug effects
*Biofilms/drug effects/growth & development
*Silver/pharmacology/chemistry
*Plant Extracts/pharmacology/chemistry
*Moringa oleifera/chemistry
*Metal Nanoparticles/chemistry
Microscopy, Electron, Scanning
*Antifungal Agents/pharmacology
Microbial Sensitivity Tests
*Photosensitizing Agents/pharmacology
Plant Leaves/chemistry
RevDate: 2025-05-28
Stereoisomeric AIE Photosensitizers for Biofilm Inhibition and Host-Directed Elimination of Intracellular Multidrug-Resistant Bacteria.
ACS applied materials & interfaces [Epub ahead of print].
Bacteria can form biofilms on their surfaces or escape from the phagosomes and multiply in the cytoplasm to become intracellular bacteria, presenting a challenge for antibiotics to reach the bacterial cells and consequently making treatment difficult. In light of this, we employed two cis-trans molecules with aggregation-induced emission (AIE) properties, (E)- and (Z)-TPE-EPy, which have the ability to hinder Gram-positive (G+) bacteria Staphylococcus aureus (S. aureus) and methicillin-resistant S. aureus (MRSA) biofilm formation by reactive oxygen species (ROS) and eradicate intracellular MRSA by host-directed therapy (HDT). These molecules can bind to the intracellular bacteria, target mitochondria, and generate ROS in situ, reduce mitochondrial membrane potential, subsequently induce autophagy to clear intracellular bacteria, and reduce inflammation. Also, these AIE luminogens (AIEgens) can promote the healing of wounds with MRSA infection by killing bacteria and regulating wound inflammation. Our findings shed a light on the potential application of AIEgens in antimicrobial therapy and developed an available strategy against intracellular bacteria.
Additional Links: PMID-40434840
Publisher:
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40434840,
year = {2025},
author = {Song, J and Chen, G and Zhu, W and Wu, Y and Xu, S and Wang, K and Kong, Y and Liang, L and Peng, HQ and Dong, J and Zhao, Z and Li, Y},
title = {Stereoisomeric AIE Photosensitizers for Biofilm Inhibition and Host-Directed Elimination of Intracellular Multidrug-Resistant Bacteria.},
journal = {ACS applied materials & interfaces},
volume = {},
number = {},
pages = {},
doi = {10.1021/acsami.5c04600},
pmid = {40434840},
issn = {1944-8252},
abstract = {Bacteria can form biofilms on their surfaces or escape from the phagosomes and multiply in the cytoplasm to become intracellular bacteria, presenting a challenge for antibiotics to reach the bacterial cells and consequently making treatment difficult. In light of this, we employed two cis-trans molecules with aggregation-induced emission (AIE) properties, (E)- and (Z)-TPE-EPy, which have the ability to hinder Gram-positive (G+) bacteria Staphylococcus aureus (S. aureus) and methicillin-resistant S. aureus (MRSA) biofilm formation by reactive oxygen species (ROS) and eradicate intracellular MRSA by host-directed therapy (HDT). These molecules can bind to the intracellular bacteria, target mitochondria, and generate ROS in situ, reduce mitochondrial membrane potential, subsequently induce autophagy to clear intracellular bacteria, and reduce inflammation. Also, these AIE luminogens (AIEgens) can promote the healing of wounds with MRSA infection by killing bacteria and regulating wound inflammation. Our findings shed a light on the potential application of AIEgens in antimicrobial therapy and developed an available strategy against intracellular bacteria.},
}
RevDate: 2025-05-28
Influence of sub-inhibitory concentrations of antiseptics on biofilm formation in S. epidermidis.
Brazilian journal of microbiology : [publication of the Brazilian Society for Microbiology] [Epub ahead of print].
Clinical isolates of Staphylococcus epidermidis were evaluated for biofilm production/chemical nature, and for the effect of sub-inhibitory concentrations (sub-MICs) of ethanol and chlorhexidine on biofilm production. Moreover, some of the biofilm-positive samples were studied for the effect of sub-MICs of these antiseptics in the expression of icaA, icaR, sigB and sarA genes. Sub-MICs of ethanol (2 and/or 4%) led to an increase in biofilm production in almost all PIA-dependent and all PIA-independent strains tested, but did not induce biofilm production in primarily non- producers. Unlike ethanol, chlorhexidine sub-MICs determined reduction in biofilm production in biofilm-positive strains. In PIA-dependent strains, ethanol (1%) caused an increase in the relative expression of icaA and reduced expression of icaR, in addition to increased expression of global regulators (sarA and sigB), while the PIA-independent strain showed reduction in the expression of these global regulators. Unlike ethanol, chlorhexidine (0.5 µg/mL) determined increased expression of icaR and reduction of icaA in PIA-dependent strains, besides a reduction in the expression of sarA and sigB in the PIA-independent strain. The opposite effects of ethanol and chlorhexidine on the expression of icaA and icaR in PIA-dependent strains corroborated the phenotypic results obtained for biofilm production in isolates exposed to these antiseptics. The biofilm-inducing or -inhibiting effects of ethanol and chlorhexidine are of practical importance due to their widespread use as antiseptics in healthcare settings.
Additional Links: PMID-40434624
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40434624,
year = {2025},
author = {da Silva Filho, RG and de Lima E Silva, AA and de Meirelles Saramago, CS and Bôas, MHSV},
title = {Influence of sub-inhibitory concentrations of antiseptics on biofilm formation in S. epidermidis.},
journal = {Brazilian journal of microbiology : [publication of the Brazilian Society for Microbiology]},
volume = {},
number = {},
pages = {},
pmid = {40434624},
issn = {1678-4405},
abstract = {Clinical isolates of Staphylococcus epidermidis were evaluated for biofilm production/chemical nature, and for the effect of sub-inhibitory concentrations (sub-MICs) of ethanol and chlorhexidine on biofilm production. Moreover, some of the biofilm-positive samples were studied for the effect of sub-MICs of these antiseptics in the expression of icaA, icaR, sigB and sarA genes. Sub-MICs of ethanol (2 and/or 4%) led to an increase in biofilm production in almost all PIA-dependent and all PIA-independent strains tested, but did not induce biofilm production in primarily non- producers. Unlike ethanol, chlorhexidine sub-MICs determined reduction in biofilm production in biofilm-positive strains. In PIA-dependent strains, ethanol (1%) caused an increase in the relative expression of icaA and reduced expression of icaR, in addition to increased expression of global regulators (sarA and sigB), while the PIA-independent strain showed reduction in the expression of these global regulators. Unlike ethanol, chlorhexidine (0.5 µg/mL) determined increased expression of icaR and reduction of icaA in PIA-dependent strains, besides a reduction in the expression of sarA and sigB in the PIA-independent strain. The opposite effects of ethanol and chlorhexidine on the expression of icaA and icaR in PIA-dependent strains corroborated the phenotypic results obtained for biofilm production in isolates exposed to these antiseptics. The biofilm-inducing or -inhibiting effects of ethanol and chlorhexidine are of practical importance due to their widespread use as antiseptics in healthcare settings.},
}
RevDate: 2025-05-28
A multi-strain, biofilm-forming cocktail of Bacillus spp. and Pediococcus spp. alters the microbial composition on polyethylene calf housing surfaces.
Microbiology spectrum [Epub ahead of print].
Application of a beneficial microbial cocktail of Bacillus spp. and Pediococcus spp. was evaluated first for adherence to polyethylene calf hutch material, and second, to determine if application in situ to individual calf hutches post-cleaning influenced surface recolonization by enteric pathogens. Three treatments were utilized: (i) no application (NC), (ii) chlorine-free, distilled water (DW), or (iii) an application of a microbial inoculant containing Bacillus spp. and Pediococcus spp. at a concentration of 0.4 g/m[2] of hutch space (LF). Thirty-six 15 × 15 cm pieces of naïve, sterile polyethylene calf hutch material received either NC or LF and were incubated at 28°C, and bacterial growth was evaluated by total aerobic plate counts at 24, 48, and 72 h post-application. Thirty polyethylene calf hutches (n = 10/treatment) were randomized to NC, DW, or LF 24 h after cleaning. Calves were placed in the hutches 24 h after treatment application and monitored daily for 28 d. In situ surface samples were randomized by time from five unique locations within the calf hutch interior: 24 h post-cleaning and then 24 h, 7 d, 14 d, and 21 d post-application. Total aerobic plate counts and culture-independent approaches RT-qPCR and 16S amplicon sequencing were used to detect and identify the composition of the bacterial community in situ. The bacteria in the inoculant were able to successfully colonize on polyethylene, and application to individual polyethylene calf housing in situ influenced microbial diversity and reduced the presence of some undesirable bacteria on high-contact interior surfaces.IMPORTANCEDue to its multifactorial nature, neonatal calf diarrhea can be difficult to manage on farms. Clean housing environments are a critical disease control point, especially for calves less than one month of age. Application of a beneficial biofilm-forming bacterial product after cleaning of neonatal calf housing may influence the microbial communities present on the surface, particularly those that may present disease risk to calves in early life.
Additional Links: PMID-40434129
Publisher:
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40434129,
year = {2025},
author = {Reynolds, CA and Scuderi, RA and Skidmore, AL and Duniere, L and Morrison, SY},
title = {A multi-strain, biofilm-forming cocktail of Bacillus spp. and Pediococcus spp. alters the microbial composition on polyethylene calf housing surfaces.},
journal = {Microbiology spectrum},
volume = {},
number = {},
pages = {e0330224},
doi = {10.1128/spectrum.03302-24},
pmid = {40434129},
issn = {2165-0497},
abstract = {Application of a beneficial microbial cocktail of Bacillus spp. and Pediococcus spp. was evaluated first for adherence to polyethylene calf hutch material, and second, to determine if application in situ to individual calf hutches post-cleaning influenced surface recolonization by enteric pathogens. Three treatments were utilized: (i) no application (NC), (ii) chlorine-free, distilled water (DW), or (iii) an application of a microbial inoculant containing Bacillus spp. and Pediococcus spp. at a concentration of 0.4 g/m[2] of hutch space (LF). Thirty-six 15 × 15 cm pieces of naïve, sterile polyethylene calf hutch material received either NC or LF and were incubated at 28°C, and bacterial growth was evaluated by total aerobic plate counts at 24, 48, and 72 h post-application. Thirty polyethylene calf hutches (n = 10/treatment) were randomized to NC, DW, or LF 24 h after cleaning. Calves were placed in the hutches 24 h after treatment application and monitored daily for 28 d. In situ surface samples were randomized by time from five unique locations within the calf hutch interior: 24 h post-cleaning and then 24 h, 7 d, 14 d, and 21 d post-application. Total aerobic plate counts and culture-independent approaches RT-qPCR and 16S amplicon sequencing were used to detect and identify the composition of the bacterial community in situ. The bacteria in the inoculant were able to successfully colonize on polyethylene, and application to individual polyethylene calf housing in situ influenced microbial diversity and reduced the presence of some undesirable bacteria on high-contact interior surfaces.IMPORTANCEDue to its multifactorial nature, neonatal calf diarrhea can be difficult to manage on farms. Clean housing environments are a critical disease control point, especially for calves less than one month of age. Application of a beneficial biofilm-forming bacterial product after cleaning of neonatal calf housing may influence the microbial communities present on the surface, particularly those that may present disease risk to calves in early life.},
}
RevDate: 2025-05-28
Development and Characterization of a Collagen-Based Three-Dimensional In Vitro Model to Mimic Biofilm Formation in a Wound Bed.
ACS applied bio materials [Epub ahead of print].
Current studies using in vitro biofilm culturing systems have been instrumental at elucidating wound biofilm formation but fail to account for the diverse environment that bacteria are exposed to within the host. In the current study, we recapitulated this wound biofilm microenvironment by creating a hydrogel composed of collagen, thrombin, fibrinogen, meat broth, and FBS and subsequently infected the scaffolds with UAMS-1. We characterized the material properties of the hydrogel (noninfected) and found no significant differences in the storage modulus when fibrin was added to the collagen hydrogel. When infected with UAMS-1, temporal growth and polysaccharide formation were observed through plating, SEM, and histological staining, indicative of biofilm formation. PCR analysis revealed heightened expression of adhesion-associated genes with no increase in expression of metabolic genes, indicating significant increase in the formation of a robust biofilm over time. Vancomycin was ineffective in eradicating the already-developed biofilm, whereas the total CFUs in rifampin-treated models decreased significantly compared to those in the untreated group. Although it was not significant, an increase in SCVs was observed in the rifampin-treated group, suggesting that rifampin may create a harsher environment against the Staphylococcus aureus, allowing the increase in more resistant bacteria. The persistence of an infection in our rifampin-treated 3D in vitro wound model indicates an increased similarity to the host environment compared to that of a static biofilm model.
Additional Links: PMID-40433975
Publisher:
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40433975,
year = {2025},
author = {Zuniga, K and Thompson, M and Muire, PJ and Clay, N and Karna, SLR and Leatherman, L and Lopez, R and You, T and Harm, K and Brammer, J and Wenke, J and Christy, R and Kowalczewski, C},
title = {Development and Characterization of a Collagen-Based Three-Dimensional In Vitro Model to Mimic Biofilm Formation in a Wound Bed.},
journal = {ACS applied bio materials},
volume = {},
number = {},
pages = {},
doi = {10.1021/acsabm.5c00100},
pmid = {40433975},
issn = {2576-6422},
abstract = {Current studies using in vitro biofilm culturing systems have been instrumental at elucidating wound biofilm formation but fail to account for the diverse environment that bacteria are exposed to within the host. In the current study, we recapitulated this wound biofilm microenvironment by creating a hydrogel composed of collagen, thrombin, fibrinogen, meat broth, and FBS and subsequently infected the scaffolds with UAMS-1. We characterized the material properties of the hydrogel (noninfected) and found no significant differences in the storage modulus when fibrin was added to the collagen hydrogel. When infected with UAMS-1, temporal growth and polysaccharide formation were observed through plating, SEM, and histological staining, indicative of biofilm formation. PCR analysis revealed heightened expression of adhesion-associated genes with no increase in expression of metabolic genes, indicating significant increase in the formation of a robust biofilm over time. Vancomycin was ineffective in eradicating the already-developed biofilm, whereas the total CFUs in rifampin-treated models decreased significantly compared to those in the untreated group. Although it was not significant, an increase in SCVs was observed in the rifampin-treated group, suggesting that rifampin may create a harsher environment against the Staphylococcus aureus, allowing the increase in more resistant bacteria. The persistence of an infection in our rifampin-treated 3D in vitro wound model indicates an increased similarity to the host environment compared to that of a static biofilm model.},
}
RevDate: 2025-05-28
Probiotic biofilm modified bioceramics for bone defect healing via osteogenesis, angiogenesis, and immune modulation.
Frontiers in pharmacology, 16:1588023.
The failure to repair bone defects in a timely manner has a detrimental effect on patients' quality of life and functional status. Consequently, there are increasing demands for medical interventions to promote healing of bone defects. However, the local inflammation induced by implants and the side effects associated with the systemic use of drugs have prompted research into the development of bioactive materials. Recent reports have indicated that oral administration of Lactobacillus acidophilus (LA) can act as an immunomodulator. In this study, we have strategically designed bioceramic scaffolds modified with inactivated LA biofilms (LA@BC) through UV irradiation for localized application of LA. The biosafety of the scaffold was validated at the cellular and animal levels to ensure that it can be safely used without bacteraemia. LA@BC achieved M1 to M2 polarization of macrophages in vitro by reducing the secretion of inflammatory factors. In addition, LA@BC enhanced the osteogenic effect of bone marrow mesenchymal stem cells by modulating the Wnt/β-catenin signaling pathway. Furthermore, osteogenesis and angiogenesis complement each other. LA@BC exerted a positive effect on the angiogenic effect of endothelial cells. In a rat cranial defect model, LA@BC upregulated the expression of RUNX2, OCN, CD31, and IL-10 in tissues, again demonstrating potent immunomodulatory and osteogenic effects. In conclusion, this bioactive scaffold provides a new strategy for clinical bone repair.
Additional Links: PMID-40432884
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40432884,
year = {2025},
author = {Su, J and Gu, H and Huang, X and Yuan, Y and Zhao, Y and Yang, F and Zhao, Y},
title = {Probiotic biofilm modified bioceramics for bone defect healing via osteogenesis, angiogenesis, and immune modulation.},
journal = {Frontiers in pharmacology},
volume = {16},
number = {},
pages = {1588023},
pmid = {40432884},
issn = {1663-9812},
abstract = {The failure to repair bone defects in a timely manner has a detrimental effect on patients' quality of life and functional status. Consequently, there are increasing demands for medical interventions to promote healing of bone defects. However, the local inflammation induced by implants and the side effects associated with the systemic use of drugs have prompted research into the development of bioactive materials. Recent reports have indicated that oral administration of Lactobacillus acidophilus (LA) can act as an immunomodulator. In this study, we have strategically designed bioceramic scaffolds modified with inactivated LA biofilms (LA@BC) through UV irradiation for localized application of LA. The biosafety of the scaffold was validated at the cellular and animal levels to ensure that it can be safely used without bacteraemia. LA@BC achieved M1 to M2 polarization of macrophages in vitro by reducing the secretion of inflammatory factors. In addition, LA@BC enhanced the osteogenic effect of bone marrow mesenchymal stem cells by modulating the Wnt/β-catenin signaling pathway. Furthermore, osteogenesis and angiogenesis complement each other. LA@BC exerted a positive effect on the angiogenic effect of endothelial cells. In a rat cranial defect model, LA@BC upregulated the expression of RUNX2, OCN, CD31, and IL-10 in tissues, again demonstrating potent immunomodulatory and osteogenic effects. In conclusion, this bioactive scaffold provides a new strategy for clinical bone repair.},
}
RevDate: 2025-05-28
CmpDate: 2025-05-28
Klebsiella Lytic Phages Induce Pseudomonas aeruginosa PAO1 Biofilm Formation.
Viruses, 17(5): pii:v17050615.
Bacterial biofilms, characterized by complex structures, molecular communication, adaptability to environmental changes, insensitivity to chemicals, and immune response, pose a big problem both in clinics and in everyday life. The increasing bacterial resistance to antibiotics also led to the exploration of lytic bacteriophages as alternatives. Nevertheless, bacteria have co-evolved with phages, developing effective antiviral strategies, notably modification or masking phage receptors as the first line of defense mechanism. This study investigates viral-host interactions between non-host-specific phages and Pseudomonas aeruginosa, assessing whether bacteria can detect phage particles and initiate protective mechanisms. Using real-time biofilm monitoring via impedance and optical density techniques, we monitored the phage effects on biofilm and planktonic populations. Three Klebsiella phages, Slopekvirus KP15, Drulisvirus KP34, and Webervirus KP36, were tested against the P. aeruginosa PAO1 population, as well as Pseudomonas Pbunavirus KTN6. The results indicated that Klebsiella phages (non-specific to P. aeruginosa), particularly podovirus KP34, accelerated biofilm formation without affecting planktonic cultures. Our hypothesis suggests that bacteria sense phage virions, regardless of specificity, triggering biofilm matrix formation to block potential phage adsorption and infection. Nevertheless, further research is needed to understand the ecological and evolutionary dynamics between phages and bacteria, which is crucial for developing novel antibiofilm therapies.
Additional Links: PMID-40431627
Publisher:
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40431627,
year = {2025},
author = {Guła, G and Majkowska-Skrobek, G and Misterkiewicz, A and Salwińska, W and Piasecki, T and Drulis-Kawa, Z},
title = {Klebsiella Lytic Phages Induce Pseudomonas aeruginosa PAO1 Biofilm Formation.},
journal = {Viruses},
volume = {17},
number = {5},
pages = {},
doi = {10.3390/v17050615},
pmid = {40431627},
issn = {1999-4915},
support = {UMO-2016/21/B/NZ6/01157//National Science Center/ ; UMO-2022/04/Y/NZ6/00123//National Science Center/ ; },
mesh = {*Biofilms/growth & development ; *Pseudomonas aeruginosa/virology/physiology ; *Klebsiella/virology ; *Pseudomonas Phages/physiology ; *Bacteriophages/physiology ; },
abstract = {Bacterial biofilms, characterized by complex structures, molecular communication, adaptability to environmental changes, insensitivity to chemicals, and immune response, pose a big problem both in clinics and in everyday life. The increasing bacterial resistance to antibiotics also led to the exploration of lytic bacteriophages as alternatives. Nevertheless, bacteria have co-evolved with phages, developing effective antiviral strategies, notably modification or masking phage receptors as the first line of defense mechanism. This study investigates viral-host interactions between non-host-specific phages and Pseudomonas aeruginosa, assessing whether bacteria can detect phage particles and initiate protective mechanisms. Using real-time biofilm monitoring via impedance and optical density techniques, we monitored the phage effects on biofilm and planktonic populations. Three Klebsiella phages, Slopekvirus KP15, Drulisvirus KP34, and Webervirus KP36, were tested against the P. aeruginosa PAO1 population, as well as Pseudomonas Pbunavirus KTN6. The results indicated that Klebsiella phages (non-specific to P. aeruginosa), particularly podovirus KP34, accelerated biofilm formation without affecting planktonic cultures. Our hypothesis suggests that bacteria sense phage virions, regardless of specificity, triggering biofilm matrix formation to block potential phage adsorption and infection. Nevertheless, further research is needed to understand the ecological and evolutionary dynamics between phages and bacteria, which is crucial for developing novel antibiofilm therapies.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
*Biofilms/growth & development
*Pseudomonas aeruginosa/virology/physiology
*Klebsiella/virology
*Pseudomonas Phages/physiology
*Bacteriophages/physiology
RevDate: 2025-05-28
Polyhexamethylene Biguanide Nanoparticles Inhibit Biofilm Formation by Mastitis-Causing Staphylococcus aureus.
Veterinary sciences, 12(5): pii:vetsci12050507.
Staphylococcus aureus is a mastitis pathogen that compromises cow health and causes significant economic losses in the dairy industry. High antimicrobial resistance and biofilm formation by S. aureus limit the efficacy of conventional treatments. This study evaluated the potential of polyhexamethylene biguanide nanoparticles (PHMB NPs) against mastitis-causing S. aureus. PHMB NPs showed low toxicity to bovine mammary epithelial cells (MAC-T cells) at concentrations up to four times higher than the minimum inhibitory concentration (1 µg/mL) against S. aureus. In Experiment 1, PHMB NPs significantly reduced biofilm formation by S. aureus by 50% at concentrations ≥1 µg/mL, though they showed limited efficacy against preformed biofilms. In Experiment 2, using an excised teat model, PHMB NPs reduced S. aureus concentrations by 37.57% compared to conventional disinfectants (chlorhexidine gluconate, povidone-iodine, and sodium dichloroisocyanurate), though limited by short contact time. These findings highlight the potential of PHMB NPs for the control of S. aureus growth and biofilm formation.
Additional Links: PMID-40431600
Publisher:
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40431600,
year = {2025},
author = {Leite, RF and Garcia, BLN and Barbosa, KDS and Mitsunaga, TM and Fidelis, CE and Dias, BJM and Miranda, RR and Zucolotto, V and Good, L and Santos, MVD},
title = {Polyhexamethylene Biguanide Nanoparticles Inhibit Biofilm Formation by Mastitis-Causing Staphylococcus aureus.},
journal = {Veterinary sciences},
volume = {12},
number = {5},
pages = {},
doi = {10.3390/vetsci12050507},
pmid = {40431600},
issn = {2306-7381},
support = {2017/50461-5//São Paulo Research Foundation/ ; },
abstract = {Staphylococcus aureus is a mastitis pathogen that compromises cow health and causes significant economic losses in the dairy industry. High antimicrobial resistance and biofilm formation by S. aureus limit the efficacy of conventional treatments. This study evaluated the potential of polyhexamethylene biguanide nanoparticles (PHMB NPs) against mastitis-causing S. aureus. PHMB NPs showed low toxicity to bovine mammary epithelial cells (MAC-T cells) at concentrations up to four times higher than the minimum inhibitory concentration (1 µg/mL) against S. aureus. In Experiment 1, PHMB NPs significantly reduced biofilm formation by S. aureus by 50% at concentrations ≥1 µg/mL, though they showed limited efficacy against preformed biofilms. In Experiment 2, using an excised teat model, PHMB NPs reduced S. aureus concentrations by 37.57% compared to conventional disinfectants (chlorhexidine gluconate, povidone-iodine, and sodium dichloroisocyanurate), though limited by short contact time. These findings highlight the potential of PHMB NPs for the control of S. aureus growth and biofilm formation.},
}
RevDate: 2025-05-28
Anti-Biofilm Properties of Cell-Free Supernatant from Bacillus velezensis EA73 by In Vitro Study with Staphylococcus aureus.
Microorganisms, 13(5): pii:microorganisms13051162.
Endophytes are a potential source of novel bioactive antimicrobial compounds. A previous study showed that Bacillus velezensis EA73, an endophytic bacterium, has promising antibacterial activity against Staphylococcus aureus; however, the mechanisms associated with its activity have still not been investigated. Therefore, this study was conducted to investigate the molecular mechanisms involved in the anti-biofilm activity of a cell-free supernatant (CFS) of B. velezensis EA73 against S. aureus. In this experiment, the biofilm-eliminating effects of a CFS of B. velezensis EA73 against S. aureus were examined in vitro. RT-qPCR was used to detect the changes in genes related to biofilm formation, whereas network pharmacology was used to predict the key targets and pathways of a cell-free supernatant of B. velezensis EA73 against S. aureus-mediated diseases. The minimum biofilm eradication concentration (MBEC) of the EA73 CFS against S. aureus was 1.28 × 10[-3] g/mL. In addition, we observed that the EA73 CFS reduced bacterial adhesion and decreased extracellular proteins, polysaccharides, and the eDNA content in the biofilm and decreased the expression of biofilm-associated genes, such as icaA and sarA. The EA73 CFS had a significant effect on S. aureus biofilm eradication and hence can serve as a promising antibacterial reagent.
Additional Links: PMID-40431333
Publisher:
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40431333,
year = {2025},
author = {Tang, Z and Yousif, M and Okyere, SK and Liao, F and Peng, S and Cheng, L and Yang, F and Wang, Y and Hu, Y},
title = {Anti-Biofilm Properties of Cell-Free Supernatant from Bacillus velezensis EA73 by In Vitro Study with Staphylococcus aureus.},
journal = {Microorganisms},
volume = {13},
number = {5},
pages = {},
doi = {10.3390/microorganisms13051162},
pmid = {40431333},
issn = {2076-2607},
support = {2015SZ0201//the Science and Technology Support Program/ ; 2020YFS0337//The Key Research and Development Project of Sichuan Province/ ; },
abstract = {Endophytes are a potential source of novel bioactive antimicrobial compounds. A previous study showed that Bacillus velezensis EA73, an endophytic bacterium, has promising antibacterial activity against Staphylococcus aureus; however, the mechanisms associated with its activity have still not been investigated. Therefore, this study was conducted to investigate the molecular mechanisms involved in the anti-biofilm activity of a cell-free supernatant (CFS) of B. velezensis EA73 against S. aureus. In this experiment, the biofilm-eliminating effects of a CFS of B. velezensis EA73 against S. aureus were examined in vitro. RT-qPCR was used to detect the changes in genes related to biofilm formation, whereas network pharmacology was used to predict the key targets and pathways of a cell-free supernatant of B. velezensis EA73 against S. aureus-mediated diseases. The minimum biofilm eradication concentration (MBEC) of the EA73 CFS against S. aureus was 1.28 × 10[-3] g/mL. In addition, we observed that the EA73 CFS reduced bacterial adhesion and decreased extracellular proteins, polysaccharides, and the eDNA content in the biofilm and decreased the expression of biofilm-associated genes, such as icaA and sarA. The EA73 CFS had a significant effect on S. aureus biofilm eradication and hence can serve as a promising antibacterial reagent.},
}
RevDate: 2025-05-28
Qualitative Assessment of Microalgae-Bacteria Biofilm Development on K5 Carriers: Photoheterotrophic Growth in Wastewater.
Microorganisms, 13(5): pii:microorganisms13051060.
Wastewater (WW) treatment using biofilms harboring bacteria and microalgae is considered a promising polishing solution to improve current treatment technologies present in wastewater treatment plants (WWTPs), but their interaction in a sessile community remains to be understood. In this work, multi-species biofilms of Chlorella vulgaris, Chlorella sorokiniana, or Scenedesmus obliquus were selected as representative microalgae species of interest for WW bioremediation, and Rhodococcus fascians, Acinetobacter calcoaceticus, or Leucobacter sp. were selected as the bacteria for co-cultivation in a synthetic WW since they are normally found in WW treatment processes. The attached consortia were developed in specific carriers (K5 carriers) for 168 h, and their biofilm formation ability was evaluated in a profilometer and via scanning electron microscopy (SEM) imaging. From the selected microorganisms, C. sorokiniana was the microalga that adapted best to co-cultivation with R. fascians and A. calcoaceticus, developing a thicker biofilm in these two consortia (3.44 ± 0.5 and 4.51 ± 0.8 µm, respectively) in comparison to the respective axenic cultures (2.55 ± 0.7 µm). In contrast, Leucobacter sp. did not promote biofilm growth in association with C. vulgaris and C. sorokiniana, while S. obliquus was not disturbed by the presence of this bacterium. Some bacterial clusters were observed through SEM, especially in A. calcoaceticus cultures in the presence of microalgae. In some combinations (especially when C. vulgaris was co-cultivated with bacteria), the presence of bacteria was able to increase the number of microalga cells adhered to the K5 carrier. This study shows that biofilm development was distinctly dependent on the co-cultivated species, where synergy in biofilm formation was highly dependent on the microalgae and bacteria species. Moreover, profilometry appears to be a promising method for biofilm analyses.
Additional Links: PMID-40431233
Publisher:
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40431233,
year = {2025},
author = {Sousa, H and Kinney, KA and Sousa, CA and Simões, M},
title = {Qualitative Assessment of Microalgae-Bacteria Biofilm Development on K5 Carriers: Photoheterotrophic Growth in Wastewater.},
journal = {Microorganisms},
volume = {13},
number = {5},
pages = {},
doi = {10.3390/microorganisms13051060},
pmid = {40431233},
issn = {2076-2607},
support = {LEPABE, UIDB/00511/2020 (DOI: 10.54499/UIDB/00511/2020) and UIDP/00511/2020 (DOI:10.54499/UIDP/00511/2020) and ALiCE, LA/P/0045/2020 (DOI: 10.54499/LA/P/0045/2020)//FCT/MCTES (PIDDAC)/ ; Henrique Sousa (2020.09538.BD)//Fundação para a Ciência e Tecnologia/ ; },
abstract = {Wastewater (WW) treatment using biofilms harboring bacteria and microalgae is considered a promising polishing solution to improve current treatment technologies present in wastewater treatment plants (WWTPs), but their interaction in a sessile community remains to be understood. In this work, multi-species biofilms of Chlorella vulgaris, Chlorella sorokiniana, or Scenedesmus obliquus were selected as representative microalgae species of interest for WW bioremediation, and Rhodococcus fascians, Acinetobacter calcoaceticus, or Leucobacter sp. were selected as the bacteria for co-cultivation in a synthetic WW since they are normally found in WW treatment processes. The attached consortia were developed in specific carriers (K5 carriers) for 168 h, and their biofilm formation ability was evaluated in a profilometer and via scanning electron microscopy (SEM) imaging. From the selected microorganisms, C. sorokiniana was the microalga that adapted best to co-cultivation with R. fascians and A. calcoaceticus, developing a thicker biofilm in these two consortia (3.44 ± 0.5 and 4.51 ± 0.8 µm, respectively) in comparison to the respective axenic cultures (2.55 ± 0.7 µm). In contrast, Leucobacter sp. did not promote biofilm growth in association with C. vulgaris and C. sorokiniana, while S. obliquus was not disturbed by the presence of this bacterium. Some bacterial clusters were observed through SEM, especially in A. calcoaceticus cultures in the presence of microalgae. In some combinations (especially when C. vulgaris was co-cultivated with bacteria), the presence of bacteria was able to increase the number of microalga cells adhered to the K5 carrier. This study shows that biofilm development was distinctly dependent on the co-cultivated species, where synergy in biofilm formation was highly dependent on the microalgae and bacteria species. Moreover, profilometry appears to be a promising method for biofilm analyses.},
}
RevDate: 2025-05-28
Biofilm Composition Changes During Orthodontic Clear Aligners Compared to Multibracket Appliances: A Systematic Review.
Microorganisms, 13(5): pii:microorganisms13051039.
Clear aligner treatment seems to be a good option for the periodontal patient by the reason of being removable. Multibracket appliances are more difficult to mantain clean and some bacteria might prefer to adhere on the archwire. A systematic review was carried out using 4 electronic databases (Pubmed-Medline, Scopus, Cochrane and Web of Science). The selected trials included quantitative (Shannon index, Simpson index, relative abundances) and/or qualitative (alpha and beta diversity) analysis in patients using clear aligners and multibracket appliances. Initially, a total of 123 articles were found after selecting clinical trials. The inclusion and exclusion criteria were applied by two authors. Finally, 20 articles were selected for the systematic review. The results showed that clear aligner treatment produced less dysbiosis in the selected bacteria compared to multibracket appliances. However, some microbiological changes were observed in some articles during clear aligner use. Oral dysibiosis was related with intestinal dysbiosis, inflammatory response and even cancer. The Firmicutes/Bacteroidetes ratio showed to have a very important role in this development. Periodontitis is also a bacterial disease and clear aligners were recommended to periodontal risk patients. Clear aligner treatment obtained less supra and subgingival biofilm changes compared with multibracket appliances but some bacteria were altered during treatment.
Additional Links: PMID-40431212
Publisher:
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40431212,
year = {2025},
author = {Belanche Monterde, A and Flores-Fraile, J and Pérez Pevida, E and Zubizarreta-Macho, Á},
title = {Biofilm Composition Changes During Orthodontic Clear Aligners Compared to Multibracket Appliances: A Systematic Review.},
journal = {Microorganisms},
volume = {13},
number = {5},
pages = {},
doi = {10.3390/microorganisms13051039},
pmid = {40431212},
issn = {2076-2607},
abstract = {Clear aligner treatment seems to be a good option for the periodontal patient by the reason of being removable. Multibracket appliances are more difficult to mantain clean and some bacteria might prefer to adhere on the archwire. A systematic review was carried out using 4 electronic databases (Pubmed-Medline, Scopus, Cochrane and Web of Science). The selected trials included quantitative (Shannon index, Simpson index, relative abundances) and/or qualitative (alpha and beta diversity) analysis in patients using clear aligners and multibracket appliances. Initially, a total of 123 articles were found after selecting clinical trials. The inclusion and exclusion criteria were applied by two authors. Finally, 20 articles were selected for the systematic review. The results showed that clear aligner treatment produced less dysbiosis in the selected bacteria compared to multibracket appliances. However, some microbiological changes were observed in some articles during clear aligner use. Oral dysibiosis was related with intestinal dysbiosis, inflammatory response and even cancer. The Firmicutes/Bacteroidetes ratio showed to have a very important role in this development. Periodontitis is also a bacterial disease and clear aligners were recommended to periodontal risk patients. Clear aligner treatment obtained less supra and subgingival biofilm changes compared with multibracket appliances but some bacteria were altered during treatment.},
}
RevDate: 2025-05-28
Molecular Characterization, Antibiotic Resistance, and Biofilm Formation of Escherichia coli Isolated from Commercial Broilers from Four Chinese Provinces.
Microorganisms, 13(5): pii:microorganisms13051017.
Escherichia coli (E. coli) represents a significant etiological agent of colibacillosis in poultry, resulting in considerable economic losses for the global poultry sector. The present study aimed to determine molecular characterization, antibiotic resistance, and biofilm formation of E. coli strains isolated from diseased broilers from four provinces of China. A total of 200 tissue samples were collected from the intestine, liver, crop, heart, and spleen and processed for microbiological examination. Molecular detection of E. coli strains, virulence genes, and serotypes was performed using polymerase chain reaction (PCR). Antibiotic susceptibility testing and biofilm formation were assessed using disk diffusion and 96-well microtiter plate assays. The study retrieved 68% (136/200) of E. coli strains from collected samples. Most of the E. coli strains were resistant to enrofloxacin (56%), followed by cefepime (54%), amoxicillin/clavulanate (52%), streptomycin (50%), ampicillin (48%), clindamycin (47%), kanamycin (41%), polymyxin B (37%), tetracycline (35%), sulfamethoxazole/trimethoprim (33%), ceftazidime (31%), meropenem (4.7%), and florfenicol (2.9%). Similarly, the E. coli strains tested positive for at least one virulence gene and specific serotypes. Among these, O145 was the most prevalent serotype, identified in 22 isolates (16.2%), followed by O8 (12.5%), O102 (11.8%), and O9 (11.0%). The tsh gene (10.2%) was the most prevalent virulence gene. This study found that 47.1% of E. coli strains were biofilm-producing, with 62.5% exhibiting weak biofilm production, 29.7% mild biofilm production, and 7.8% strong biofilm production. Similarly, 24.2% of the E. coli strains were avian pathogenic E. coli strains due to the presence of five or more virulence genes, specifically tsh, ompA, fimC, iss, fyuA, and astA, in a single strain by multiplex PCR. The present study recommends continuous surveillance and effective control measures to reduce the burden of avian pathogenic E. coli-related infections in poultry.
Additional Links: PMID-40431190
Publisher:
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40431190,
year = {2025},
author = {Nawaz, S and Shoaib, M and Huang, C and Jiang, W and Bao, Y and Wu, X and Nie, L and Fan, W and Wang, Z and Chen, Z and Yin, H and Han, X},
title = {Molecular Characterization, Antibiotic Resistance, and Biofilm Formation of Escherichia coli Isolated from Commercial Broilers from Four Chinese Provinces.},
journal = {Microorganisms},
volume = {13},
number = {5},
pages = {},
doi = {10.3390/microorganisms13051017},
pmid = {40431190},
issn = {2076-2607},
support = {U22A20518//National Natural Science Foundation of China/ ; 32072829//National Natural Science Foundation of China/ ; 32302883//National Natural Science Foundation of China/ ; 22ZR1475800//Shanghai Natural Science Foundation of China/ ; 2021J01132429//Natural Science Foundation of Fujian Province of China/ ; },
abstract = {Escherichia coli (E. coli) represents a significant etiological agent of colibacillosis in poultry, resulting in considerable economic losses for the global poultry sector. The present study aimed to determine molecular characterization, antibiotic resistance, and biofilm formation of E. coli strains isolated from diseased broilers from four provinces of China. A total of 200 tissue samples were collected from the intestine, liver, crop, heart, and spleen and processed for microbiological examination. Molecular detection of E. coli strains, virulence genes, and serotypes was performed using polymerase chain reaction (PCR). Antibiotic susceptibility testing and biofilm formation were assessed using disk diffusion and 96-well microtiter plate assays. The study retrieved 68% (136/200) of E. coli strains from collected samples. Most of the E. coli strains were resistant to enrofloxacin (56%), followed by cefepime (54%), amoxicillin/clavulanate (52%), streptomycin (50%), ampicillin (48%), clindamycin (47%), kanamycin (41%), polymyxin B (37%), tetracycline (35%), sulfamethoxazole/trimethoprim (33%), ceftazidime (31%), meropenem (4.7%), and florfenicol (2.9%). Similarly, the E. coli strains tested positive for at least one virulence gene and specific serotypes. Among these, O145 was the most prevalent serotype, identified in 22 isolates (16.2%), followed by O8 (12.5%), O102 (11.8%), and O9 (11.0%). The tsh gene (10.2%) was the most prevalent virulence gene. This study found that 47.1% of E. coli strains were biofilm-producing, with 62.5% exhibiting weak biofilm production, 29.7% mild biofilm production, and 7.8% strong biofilm production. Similarly, 24.2% of the E. coli strains were avian pathogenic E. coli strains due to the presence of five or more virulence genes, specifically tsh, ompA, fimC, iss, fyuA, and astA, in a single strain by multiplex PCR. The present study recommends continuous surveillance and effective control measures to reduce the burden of avian pathogenic E. coli-related infections in poultry.},
}
RevDate: 2025-05-28
Emerging Concepts for the Treatment of Biofilm-Associated Bone and Joint Infections with IV Fosfomycin: A Literature Review.
Microorganisms, 13(5): pii:microorganisms13050963.
Due to the involvement of biofilms in the pathogenesis of bone and joint infections (BJI), the treatment of these infections is often challenging, especially when multidrug- or extensively drug-resistant (MDR/XDR) pathogens are involved. Intravenous fosfomycin (FOS) is a phosphoenolpyruvate analogue with a unique mode of action and broad-spectrum activity against both Gram-positive (GP) and Gram-negative (GN) pathogens. It is used in various severe and deep-seated infections, including BJIs. This review article focuses on preclinical and clinical data surrounding the use of FOS for biofilm-related BJIs. Data from several in vitro and animal models of infection demonstrated that FOS, especially in combination with other antibiotics, is effective against biofilms of (methicillin-resistant) Staphylococcus spp., (vancomycin-resistant) Enterococcus spp., carbapenem-resistant and extended-spectrum beta-lactamase-producing Enterobacterales, and MDR Pseudomonas aeruginosa. Data from clinical studies, mostly retrospective observational studies and case reports/case series, revealed that FOS was typically used in combination with other antibiotics for the treatment of various BJI, including acute and chronic osteomyelitis, prosthetic joint infections, and fracture-related infections, in adult and pediatric patients. Success rates often exceeded 80%. FOS exhibits good and fast penetration into bone tissue and is generally well tolerated, with only a few adverse drug reactions, such as gastrointestinal disorders and electrolyte imbalances. Collectively, the data indicate that FOS is a valuable option as part of combination regimens for the treatment of BJIs caused by both GP and GN bacteria.
Additional Links: PMID-40431135
Publisher:
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40431135,
year = {2025},
author = {Tedeschi, S and Giannitsioti, E and Mayer, C},
title = {Emerging Concepts for the Treatment of Biofilm-Associated Bone and Joint Infections with IV Fosfomycin: A Literature Review.},
journal = {Microorganisms},
volume = {13},
number = {5},
pages = {},
doi = {10.3390/microorganisms13050963},
pmid = {40431135},
issn = {2076-2607},
abstract = {Due to the involvement of biofilms in the pathogenesis of bone and joint infections (BJI), the treatment of these infections is often challenging, especially when multidrug- or extensively drug-resistant (MDR/XDR) pathogens are involved. Intravenous fosfomycin (FOS) is a phosphoenolpyruvate analogue with a unique mode of action and broad-spectrum activity against both Gram-positive (GP) and Gram-negative (GN) pathogens. It is used in various severe and deep-seated infections, including BJIs. This review article focuses on preclinical and clinical data surrounding the use of FOS for biofilm-related BJIs. Data from several in vitro and animal models of infection demonstrated that FOS, especially in combination with other antibiotics, is effective against biofilms of (methicillin-resistant) Staphylococcus spp., (vancomycin-resistant) Enterococcus spp., carbapenem-resistant and extended-spectrum beta-lactamase-producing Enterobacterales, and MDR Pseudomonas aeruginosa. Data from clinical studies, mostly retrospective observational studies and case reports/case series, revealed that FOS was typically used in combination with other antibiotics for the treatment of various BJI, including acute and chronic osteomyelitis, prosthetic joint infections, and fracture-related infections, in adult and pediatric patients. Success rates often exceeded 80%. FOS exhibits good and fast penetration into bone tissue and is generally well tolerated, with only a few adverse drug reactions, such as gastrointestinal disorders and electrolyte imbalances. Collectively, the data indicate that FOS is a valuable option as part of combination regimens for the treatment of BJIs caused by both GP and GN bacteria.},
}
RevDate: 2025-05-28
The Natural Anthraquinone Parietin Inactivates Candida tropicalis Biofilm by Photodynamic Mechanisms.
Pharmaceutics, 17(5): pii:pharmaceutics17050548.
Background/Objectives: Parietin (PTN), a blue-light absorbing pigment from Teloschistes spp. lichens, exhibit photosensitizing properties via Type I (superoxide anion, O2[•-]) and Type II (singlet oxygen, [1]O2) mechanisms, inactivating bacteria in vitro after photoexcitation. We evaluate the in vitro antifungal activity of PTN against Candida tropicalis biofilms under actinic irradiation, its role in O2[•-] and [1]O2 production, and the cellular stress response. Methods: Minimum inhibitory concentration (MIC) of PTN was determined in C. tropicalis NCPF 3111 under dark and actinic light conditions. Biofilm susceptibility was assessed at MIC/2, MIC, MICx2, MICx4, and MICx6 in the same conditions, and viability was measured by colony-forming units. Photodynamic mechanisms were examined using Tiron (O2[•-] scavenger) or sodium azide ([1]O2 quencher). O2[•-] production was measured by the nitro-blue tetrazolium (NBT) reduction and nitric oxide (NO) generation by Griess assay. Total antioxidant capacity was studied by FRAP (Ferrous Reduction Antioxidant Potency) assay and superoxide dismutase (SOD) activity by NBT assay. Results: Photoexcitation of PTN reduced C. tropicalis biofilm viability by four logs at MICx2. Sodium azide partially reversed the effect, whereas Tiron fully inhibited it, indicating the critical role of O2[•-]. PTN also increased O2[•-] and NO levels, enhancing SOD activity and FRAP. However, this antioxidant response was insufficient to prevent biofilm photoinactivation. Conclusions: Photoinactivation of C. tropicalis biofilms by PTN is primarily mediated by O2[•-], with a minor contribution from [1]O2 and an imbalance in NO levels. These findings suggest PTN is a promising photosensitizer for antifungal photodynamic therapy.
Additional Links: PMID-40430841
Publisher:
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40430841,
year = {2025},
author = {Marioni, J and Romero, BC and Mugas, ML and Martinez, F and Gómez, TI and Morales, JMN and Konigheim, BS and Borsarelli, CD and Nuñez-Montoya, SC},
title = {The Natural Anthraquinone Parietin Inactivates Candida tropicalis Biofilm by Photodynamic Mechanisms.},
journal = {Pharmaceutics},
volume = {17},
number = {5},
pages = {},
doi = {10.3390/pharmaceutics17050548},
pmid = {40430841},
issn = {1999-4923},
support = {Consolidar, tipo 2, s/res. N◦ 411/18 y 155/22//SeCyT UNC/ ; N◦ 4576, s/ res. ANPCyT n◦ 401/19//FONCyT (PICT 2018)/ ; s/ res. 1639/2021//CONICET (PIP 2021-2023)/ ; },
abstract = {Background/Objectives: Parietin (PTN), a blue-light absorbing pigment from Teloschistes spp. lichens, exhibit photosensitizing properties via Type I (superoxide anion, O2[•-]) and Type II (singlet oxygen, [1]O2) mechanisms, inactivating bacteria in vitro after photoexcitation. We evaluate the in vitro antifungal activity of PTN against Candida tropicalis biofilms under actinic irradiation, its role in O2[•-] and [1]O2 production, and the cellular stress response. Methods: Minimum inhibitory concentration (MIC) of PTN was determined in C. tropicalis NCPF 3111 under dark and actinic light conditions. Biofilm susceptibility was assessed at MIC/2, MIC, MICx2, MICx4, and MICx6 in the same conditions, and viability was measured by colony-forming units. Photodynamic mechanisms were examined using Tiron (O2[•-] scavenger) or sodium azide ([1]O2 quencher). O2[•-] production was measured by the nitro-blue tetrazolium (NBT) reduction and nitric oxide (NO) generation by Griess assay. Total antioxidant capacity was studied by FRAP (Ferrous Reduction Antioxidant Potency) assay and superoxide dismutase (SOD) activity by NBT assay. Results: Photoexcitation of PTN reduced C. tropicalis biofilm viability by four logs at MICx2. Sodium azide partially reversed the effect, whereas Tiron fully inhibited it, indicating the critical role of O2[•-]. PTN also increased O2[•-] and NO levels, enhancing SOD activity and FRAP. However, this antioxidant response was insufficient to prevent biofilm photoinactivation. Conclusions: Photoinactivation of C. tropicalis biofilms by PTN is primarily mediated by O2[•-], with a minor contribution from [1]O2 and an imbalance in NO levels. These findings suggest PTN is a promising photosensitizer for antifungal photodynamic therapy.},
}
RevDate: 2025-05-28
CmpDate: 2025-05-28
Inhibition of Biofilm Production and Determination of In Vitro Time-Kill Thymus vulgaris L. Essential Oil (TEO) for the Control of Mastitis in Small Ruminants.
Pathogens (Basel, Switzerland), 14(5): pii:pathogens14050412.
Staphylococcus aureus and coagulase-negative staphylococci (CNS) are the main causative agents of mastitis in sheep. Their ability to form biofilms in vivo is considered an important virulence factor underlying mastitis outbreaks refractory to antibiotic treatments. Furthermore, pre- and postdipping immersion during milking in iodine substances could determine the presence of residues in milk and therefore represent a health risk factor for consumers. The aim of this study was to evaluate the antibacterial and biofilm inhibitory activity of Thymus vulgaris L. essential oil (TEO) against staphylococci strains isolated from ovine clinical mastitis. In particular, 3 reference strains (S. aureus 25923 and 11623 and S. epidermidis 12228) and 12 clinical isolates (6 S. aureus and 6 CNS) were used. TEO solutions, from a concentration of 1% (v/v) to 1.25% (v/v), corresponding to 9.28-2.32 mg/mL, were obtained after solubilization in 10% dimethyl sulfoxide (DMSO) and used to evaluate the bacterial time-kill compared to that of an iodine-based solution. Antibacterial efficacy was then assessed by the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC), while biofilm inhibition was assessed by minimum biofilm inhibitory concentration (MBIC) using a spectrophotometer at a wavelength of 570 nm. Additionally, biofilm-associated genes (icaA and icaD) were evaluated in all tested strains by PCR. The tested TEO concentrations were able to significantly and prominently reduce bacterial growth compared to controls, as demonstrated by bacterial time-kills. The MIC value was obtained at a concentration of 0.50% (v/v) for a single coagulation-positive isolate (S. aureus (f)) and at a concentration of 0.25% (v/v) for all other isolates. TEO showed effective bactericidal action with a 99.9% reduction in CFU/mL of all isolates in the MBC test at a concentration of 0.25% (v/v) for most of the tested strains. Furthermore, a marked inhibition in biofilm formation at all tested concentrations was observed, with MBIC value of 0.25%. All S. aureus tested were biofilm-producing strains and positive for icaA and icaD genes, while two CNS biofilm-producing strains were negative for both genes. These preliminary results suggest that TEO could be a promising alternative as an udder disinfectant during milking practices. Although in vivo studies are needed to confirm the efficacy and safety of TEO as an adjuvant in the prevention and treatment of udder infections, TEO could help counteract the emergence of antimicrobial resistance and reduce the potential risk of iodine residues in milk.
Additional Links: PMID-40430732
Publisher:
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40430732,
year = {2025},
author = {Galgano, M and Pellegrini, F and Mrenoshki, D and Addante, L and Sposato, A and Del Sambro, L and Capozzi, L and Catalano, E and Solito, M and D'Amico, F and Messina, D and Parisi, A and Pratelli, A and Capozza, P},
title = {Inhibition of Biofilm Production and Determination of In Vitro Time-Kill Thymus vulgaris L. Essential Oil (TEO) for the Control of Mastitis in Small Ruminants.},
journal = {Pathogens (Basel, Switzerland)},
volume = {14},
number = {5},
pages = {},
doi = {10.3390/pathogens14050412},
pmid = {40430732},
issn = {2076-0817},
mesh = {*Biofilms/drug effects/growth & development ; Animals ; *Thymus Plant/chemistry ; *Oils, Volatile/pharmacology/isolation & purification ; Sheep ; Microbial Sensitivity Tests ; *Anti-Bacterial Agents/pharmacology ; *Mastitis/veterinary/microbiology/drug therapy ; Female ; *Staphylococcal Infections/veterinary/microbiology/drug therapy ; *Staphylococcus aureus/drug effects/physiology ; *Sheep Diseases/microbiology/drug therapy ; *Staphylococcus/drug effects/physiology ; Staphylococcus epidermidis/drug effects ; },
abstract = {Staphylococcus aureus and coagulase-negative staphylococci (CNS) are the main causative agents of mastitis in sheep. Their ability to form biofilms in vivo is considered an important virulence factor underlying mastitis outbreaks refractory to antibiotic treatments. Furthermore, pre- and postdipping immersion during milking in iodine substances could determine the presence of residues in milk and therefore represent a health risk factor for consumers. The aim of this study was to evaluate the antibacterial and biofilm inhibitory activity of Thymus vulgaris L. essential oil (TEO) against staphylococci strains isolated from ovine clinical mastitis. In particular, 3 reference strains (S. aureus 25923 and 11623 and S. epidermidis 12228) and 12 clinical isolates (6 S. aureus and 6 CNS) were used. TEO solutions, from a concentration of 1% (v/v) to 1.25% (v/v), corresponding to 9.28-2.32 mg/mL, were obtained after solubilization in 10% dimethyl sulfoxide (DMSO) and used to evaluate the bacterial time-kill compared to that of an iodine-based solution. Antibacterial efficacy was then assessed by the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC), while biofilm inhibition was assessed by minimum biofilm inhibitory concentration (MBIC) using a spectrophotometer at a wavelength of 570 nm. Additionally, biofilm-associated genes (icaA and icaD) were evaluated in all tested strains by PCR. The tested TEO concentrations were able to significantly and prominently reduce bacterial growth compared to controls, as demonstrated by bacterial time-kills. The MIC value was obtained at a concentration of 0.50% (v/v) for a single coagulation-positive isolate (S. aureus (f)) and at a concentration of 0.25% (v/v) for all other isolates. TEO showed effective bactericidal action with a 99.9% reduction in CFU/mL of all isolates in the MBC test at a concentration of 0.25% (v/v) for most of the tested strains. Furthermore, a marked inhibition in biofilm formation at all tested concentrations was observed, with MBIC value of 0.25%. All S. aureus tested were biofilm-producing strains and positive for icaA and icaD genes, while two CNS biofilm-producing strains were negative for both genes. These preliminary results suggest that TEO could be a promising alternative as an udder disinfectant during milking practices. Although in vivo studies are needed to confirm the efficacy and safety of TEO as an adjuvant in the prevention and treatment of udder infections, TEO could help counteract the emergence of antimicrobial resistance and reduce the potential risk of iodine residues in milk.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
*Biofilms/drug effects/growth & development
Animals
*Thymus Plant/chemistry
*Oils, Volatile/pharmacology/isolation & purification
Sheep
Microbial Sensitivity Tests
*Anti-Bacterial Agents/pharmacology
*Mastitis/veterinary/microbiology/drug therapy
Female
*Staphylococcal Infections/veterinary/microbiology/drug therapy
*Staphylococcus aureus/drug effects/physiology
*Sheep Diseases/microbiology/drug therapy
*Staphylococcus/drug effects/physiology
Staphylococcus epidermidis/drug effects
RevDate: 2025-05-28
CmpDate: 2025-05-28
Enhanced Biofilm Disruption in Methicillin-Resistant Staphylococcus aureus Using Rifampin and Fluoroquinolone Combinations.
Pathogens (Basel, Switzerland), 14(5): pii:pathogens14050404.
Staphylococcus aureus biofilms complicate the treatment of device-related infections. We hypothesized that combining rifampin with fluoroquinolones could eradicate biofilms even in antimicrobial-resistant S. aureus strains. We determined the synergistic interactions of these combinations in a biofilm model. Thirty methicillin-resistant S. aureus (MRSA) isolates with varying susceptibility profiles were evaluated. Minimum biofilm eradication concentrations (MBECs) were determined using the Calgary Biofilm Device, and the synergy was assessed using the fractional biofilm eradication concentration (FBEC) index. Scanning electron microscopy (SEM) was performed on one strain, and confocal laser scanning microscopy (CLSM) was conducted on four strains for visualizing and evaluating the biofilm viability. The MBEC90 for rifampin and levofloxacin were 512 mg/L and 256 mg/L, respectively, and exceeded 1024 mg/L for ciprofloxacin. Synergy was observed in 56.7% of strains for both the rifampin + ciprofloxacin and rifampin + levofloxacin combinations, with no difference between the combinations. A higher ciprofloxacin MBEC (≥16 mg/L) increased the likelihood of synergy with rifampin by 18-fold. SEM and CLSM analyses in a subset of strains confirmed the enhanced biofilm disruption with rifampin + ciprofloxacin compared to ciprofloxacin alone. Our findings suggest that rifampin combined with ciprofloxacin or levofloxacin may synergistically eradicate MRSA biofilms, offering a potential treatment option for device-related infections when alternatives are limited.
Additional Links: PMID-40430725
Publisher:
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40430725,
year = {2025},
author = {Kang, YR and Park, JY and Chung, DR and Kang, M and Ko, JH and Huh, K and Cho, SY and Kang, CI and Peck, KR},
title = {Enhanced Biofilm Disruption in Methicillin-Resistant Staphylococcus aureus Using Rifampin and Fluoroquinolone Combinations.},
journal = {Pathogens (Basel, Switzerland)},
volume = {14},
number = {5},
pages = {},
doi = {10.3390/pathogens14050404},
pmid = {40430725},
issn = {2076-0817},
support = {SMX1230761//Samsung Medical Center/ ; RS-2023-00242888//National Research Foundation of Korea/ ; },
mesh = {*Biofilms/drug effects/growth & development ; *Rifampin/pharmacology ; *Methicillin-Resistant Staphylococcus aureus/drug effects/physiology ; Microbial Sensitivity Tests ; *Anti-Bacterial Agents/pharmacology ; *Fluoroquinolones/pharmacology ; Drug Synergism ; Levofloxacin/pharmacology ; Staphylococcal Infections/microbiology/drug therapy ; Humans ; Microscopy, Electron, Scanning ; Microscopy, Confocal ; Ciprofloxacin/pharmacology ; },
abstract = {Staphylococcus aureus biofilms complicate the treatment of device-related infections. We hypothesized that combining rifampin with fluoroquinolones could eradicate biofilms even in antimicrobial-resistant S. aureus strains. We determined the synergistic interactions of these combinations in a biofilm model. Thirty methicillin-resistant S. aureus (MRSA) isolates with varying susceptibility profiles were evaluated. Minimum biofilm eradication concentrations (MBECs) were determined using the Calgary Biofilm Device, and the synergy was assessed using the fractional biofilm eradication concentration (FBEC) index. Scanning electron microscopy (SEM) was performed on one strain, and confocal laser scanning microscopy (CLSM) was conducted on four strains for visualizing and evaluating the biofilm viability. The MBEC90 for rifampin and levofloxacin were 512 mg/L and 256 mg/L, respectively, and exceeded 1024 mg/L for ciprofloxacin. Synergy was observed in 56.7% of strains for both the rifampin + ciprofloxacin and rifampin + levofloxacin combinations, with no difference between the combinations. A higher ciprofloxacin MBEC (≥16 mg/L) increased the likelihood of synergy with rifampin by 18-fold. SEM and CLSM analyses in a subset of strains confirmed the enhanced biofilm disruption with rifampin + ciprofloxacin compared to ciprofloxacin alone. Our findings suggest that rifampin combined with ciprofloxacin or levofloxacin may synergistically eradicate MRSA biofilms, offering a potential treatment option for device-related infections when alternatives are limited.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
*Biofilms/drug effects/growth & development
*Rifampin/pharmacology
*Methicillin-Resistant Staphylococcus aureus/drug effects/physiology
Microbial Sensitivity Tests
*Anti-Bacterial Agents/pharmacology
*Fluoroquinolones/pharmacology
Drug Synergism
Levofloxacin/pharmacology
Staphylococcal Infections/microbiology/drug therapy
Humans
Microscopy, Electron, Scanning
Microscopy, Confocal
Ciprofloxacin/pharmacology
RevDate: 2025-05-28
Polydopamine-Coated Magnetic Nanoplatform for Magnetically Guided Penetration and Enhanced Antibacterial Efficacy in Root Canal Biofilm Elimination.
Polymers, 17(10): pii:polym17101305.
Clinical root canal therapy which takes place through mechanical and chemical strategies is faced with challenges in eliminating bacteria owing to the intricate and curved nature of the root canal system. Moreover, the plaque biofilm within the root canal hinders drug penetration and limits treatment efficacy. Hence, efficient root canal therapy hinges on penetrating into the root canal and overcoming the barriers presented by the plaque biofilms. To penetrate and eradicate biofilms effectively at the root canal, we designed a novel magnetic nanoparticle (MN)-based nanoplatform which was synthesized by the self-polymerization of dopamine on the surface of Fe3O4 MNs, and then loaded minocycline through the electrostatic interaction. The therapeutic efficacy of minocycline-loaded magnetic nanoparticles (FDM MNs) under a magnetostatic field was observed by various antibacterial experiments. The synthesized FDM MNs exhibited favorable biocompatibility and robust anti-biofilm efficacy. The designed nanoparticles could effectively navigate biofilms to eradicate bacteria residing deep with the assistance of magnetic force. Furthermore, FDM MNs penetrated into dentin tubules under a magnetic field, effectively disrupting biofilms for deep sterilization. The significant results offered valuable experimental evidence to support the potential clinical utility of magnetic nanoparticles for managing pulpitis and periapical inflammation.
Additional Links: PMID-40430601
Publisher:
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40430601,
year = {2025},
author = {Xu, X and Wang, P and Tong, F and Liu, Y and Hu, X and Yang, J and Guo, J},
title = {Polydopamine-Coated Magnetic Nanoplatform for Magnetically Guided Penetration and Enhanced Antibacterial Efficacy in Root Canal Biofilm Elimination.},
journal = {Polymers},
volume = {17},
number = {10},
pages = {},
doi = {10.3390/polym17101305},
pmid = {40430601},
issn = {2073-4360},
support = {202410037//Technological Plan of Health Commission of Jiangxi Province of China/ ; 82060198, 82460195//National Natural Science Foundation of China/ ; 2022A329, 2024B0483//Technological Plan of Traditional Chinese Medicine Administration of Jiangxi Province of China/ ; 20212BAB206072, 20224BAB216078//Jiangxi Provincial Natural Science Foundation/ ; },
abstract = {Clinical root canal therapy which takes place through mechanical and chemical strategies is faced with challenges in eliminating bacteria owing to the intricate and curved nature of the root canal system. Moreover, the plaque biofilm within the root canal hinders drug penetration and limits treatment efficacy. Hence, efficient root canal therapy hinges on penetrating into the root canal and overcoming the barriers presented by the plaque biofilms. To penetrate and eradicate biofilms effectively at the root canal, we designed a novel magnetic nanoparticle (MN)-based nanoplatform which was synthesized by the self-polymerization of dopamine on the surface of Fe3O4 MNs, and then loaded minocycline through the electrostatic interaction. The therapeutic efficacy of minocycline-loaded magnetic nanoparticles (FDM MNs) under a magnetostatic field was observed by various antibacterial experiments. The synthesized FDM MNs exhibited favorable biocompatibility and robust anti-biofilm efficacy. The designed nanoparticles could effectively navigate biofilms to eradicate bacteria residing deep with the assistance of magnetic force. Furthermore, FDM MNs penetrated into dentin tubules under a magnetic field, effectively disrupting biofilms for deep sterilization. The significant results offered valuable experimental evidence to support the potential clinical utility of magnetic nanoparticles for managing pulpitis and periapical inflammation.},
}
RevDate: 2025-05-28
CmpDate: 2025-05-28
The RNA Chaperone Hfq and Small Non-Coding RNAs Modulate the Biofilm Formation of the Fish Pathogen Yersinia ruckeri.
International journal of molecular sciences, 26(10): pii:ijms26104733.
The fish pathogen Yersinia ruckeri forms biofilms on abiotic surfaces, contributing to recurrent infections in aquaculture. Increasing evidence suggests that the RNA chaperone Hfq and small non-coding RNAs (sRNAs) are key regulators of bacterial biofilm formation. However, the regulatory mechanisms mediated by these factors remain largely unexplored in Y. ruckeri. In this study, we investigated the roles of Hfq and the Hfq-dependent sRNAs RprA, ArcZ, and RybB in the biofilm formation of Y. ruckeri. We first characterized the sRNAome of biofilm-forming cells, identifying the conserved RprA, ArcZ, and RybB, among the upregulated sRNAs. We then evaluated motility, biofilm formation, and architecture in strains lacking either hfq (Δhfq) or these sRNAs (ΔsRNA). Our results reveal that both Δhfq and ΔsRNA strains exhibit significant alterations in biofilm and motility phenotypes, including changes in bacterial morphology and extracellular matrix. Furthermore, expression analyses indicate that these sRNAs modulate the transcription of key regulatory factors, flagellar and phosphodiesterase genes, ultimately influencing intracellular cyclic di-GMP levels, a key second messenger in biofilm formation. Together, our findings demonstrate that Hfq and its associated sRNAs play critical regulatory roles in Y. ruckeri biofilm formation by controlling the expression of genes involved in motility, bacterial envelope proteins, and c-di-GMP metabolism.
Additional Links: PMID-40429875
Publisher:
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40429875,
year = {2025},
author = {Barros, MJ and Acuña, LG and Hernández-Vera, F and Vásquez-Arriagada, P and Peñaloza, D and Moya-Beltrán, A and Cabezas-Mera, F and Parra, F and Gil, F and Fuentes, JA and Calderón, IL},
title = {The RNA Chaperone Hfq and Small Non-Coding RNAs Modulate the Biofilm Formation of the Fish Pathogen Yersinia ruckeri.},
journal = {International journal of molecular sciences},
volume = {26},
number = {10},
pages = {},
doi = {10.3390/ijms26104733},
pmid = {40429875},
issn = {1422-0067},
support = {1221610//Agencia Nacional de Investigación y Desarrollo (ANID, Chile), FONDECYT REGULAR/ ; 1220584//Agencia Nacional de Investigación y Desarrollo (ANID, Chile), FONDECYT REGULAR/ ; },
mesh = {*Biofilms/growth & development ; *Host Factor 1 Protein/genetics/metabolism ; *Yersinia ruckeri/genetics/physiology ; *RNA, Small Untranslated/genetics/metabolism ; Gene Expression Regulation, Bacterial ; Animals ; Bacterial Proteins/genetics/metabolism ; RNA, Bacterial/genetics/metabolism ; Molecular Chaperones/genetics/metabolism ; Yersinia Infections/microbiology/veterinary ; Cyclic GMP/analogs & derivatives/metabolism ; Fishes/microbiology ; },
abstract = {The fish pathogen Yersinia ruckeri forms biofilms on abiotic surfaces, contributing to recurrent infections in aquaculture. Increasing evidence suggests that the RNA chaperone Hfq and small non-coding RNAs (sRNAs) are key regulators of bacterial biofilm formation. However, the regulatory mechanisms mediated by these factors remain largely unexplored in Y. ruckeri. In this study, we investigated the roles of Hfq and the Hfq-dependent sRNAs RprA, ArcZ, and RybB in the biofilm formation of Y. ruckeri. We first characterized the sRNAome of biofilm-forming cells, identifying the conserved RprA, ArcZ, and RybB, among the upregulated sRNAs. We then evaluated motility, biofilm formation, and architecture in strains lacking either hfq (Δhfq) or these sRNAs (ΔsRNA). Our results reveal that both Δhfq and ΔsRNA strains exhibit significant alterations in biofilm and motility phenotypes, including changes in bacterial morphology and extracellular matrix. Furthermore, expression analyses indicate that these sRNAs modulate the transcription of key regulatory factors, flagellar and phosphodiesterase genes, ultimately influencing intracellular cyclic di-GMP levels, a key second messenger in biofilm formation. Together, our findings demonstrate that Hfq and its associated sRNAs play critical regulatory roles in Y. ruckeri biofilm formation by controlling the expression of genes involved in motility, bacterial envelope proteins, and c-di-GMP metabolism.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
*Biofilms/growth & development
*Host Factor 1 Protein/genetics/metabolism
*Yersinia ruckeri/genetics/physiology
*RNA, Small Untranslated/genetics/metabolism
Gene Expression Regulation, Bacterial
Animals
Bacterial Proteins/genetics/metabolism
RNA, Bacterial/genetics/metabolism
Molecular Chaperones/genetics/metabolism
Yersinia Infections/microbiology/veterinary
Cyclic GMP/analogs & derivatives/metabolism
Fishes/microbiology
RevDate: 2025-05-28
CmpDate: 2025-05-28
Next-Generation Eco-Friendly Hybrid Air Purifier: Ag/TiO2/PLA Biofilm for Enhanced Bioaerosols Removal.
International journal of molecular sciences, 26(10): pii:ijms26104584.
Indoor air pollution poses a significant public health risk, particularly in urban areas, where PM2.5 and airborne contaminants contribute to respiratory diseases. In Thailand, including Chonburi Province, PM2.5 levels frequently exceed safety thresholds, underscoring the urgent need for effective mitigation strategies. To address this challenge, we developed a hybrid air purification system incorporating a bioplastic-based photocatalytic film of polylactic acid (PLA) embedded with titanium dioxide (TiO2) nanoparticles. For optimization, PLA films were functionalized with varying TiO2 concentrations and characterized using SEM, FTIR, TGDTA, and UV-Vis. spectroscopy. A 5 wt% TiO2 loading was identified as optimal and further enhanced with silver (Ag) nanoparticles to boost photocatalytic efficiency. The Ag/TiO2/PLA biofilm was fabricated via a compound pellet formulation process followed by blown film extrusion. Various compositions, with and without Ag, were systematically evaluated for photocatalytic performance. The novel customized hybrid air purifier developed in this study is designed to enhance indoor air purification efficiency by integrating Ag/TiO2/PLA biofilms into a controlled oxidation system. The air purification efficacy of the developed biofilm was evaluated through a controlled study on Staphylococcus aureus (S. aureus) removal under different treatment conditions: control, adsorption, photolysis, and photocatalytic oxidation. The impact of light intensity on photocatalytic efficiency was also examined. The photocatalytic oxidation of S. aureus was subjected to the first-order kinetic evaluation through mathematical modeling. Results demonstrated that the Ag/TiO2/PLA biofilm significantly enhances indoor air purification, providing a sustainable, scalable, and energy-efficient solution for microbial decontamination and pollutant removal. This innovative approach outperforms conventional adsorption, adsorption and photocatalytic oxidation systems, offering a promising pathway for improved indoor air quality.
Additional Links: PMID-40429732
Publisher:
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40429732,
year = {2025},
author = {Chotigawin, R and Kandasamy, B and Asa, P and Semangoen, T and Ajawatanawong, P and Phibanchon, S and Pahasup-Anan, T and Wongcharee, S and Suwannahong, K},
title = {Next-Generation Eco-Friendly Hybrid Air Purifier: Ag/TiO2/PLA Biofilm for Enhanced Bioaerosols Removal.},
journal = {International journal of molecular sciences},
volume = {26},
number = {10},
pages = {},
doi = {10.3390/ijms26104584},
pmid = {40429732},
issn = {1422-0067},
support = {Faculty of Public Health//Burapha University/ ; },
mesh = {*Titanium/chemistry ; *Biofilms ; *Silver/chemistry ; *Polyesters/chemistry ; *Air Filters/microbiology ; Staphylococcus aureus ; Aerosols/chemistry ; *Air Pollution, Indoor/prevention & control ; Catalysis ; Metal Nanoparticles/chemistry ; },
abstract = {Indoor air pollution poses a significant public health risk, particularly in urban areas, where PM2.5 and airborne contaminants contribute to respiratory diseases. In Thailand, including Chonburi Province, PM2.5 levels frequently exceed safety thresholds, underscoring the urgent need for effective mitigation strategies. To address this challenge, we developed a hybrid air purification system incorporating a bioplastic-based photocatalytic film of polylactic acid (PLA) embedded with titanium dioxide (TiO2) nanoparticles. For optimization, PLA films were functionalized with varying TiO2 concentrations and characterized using SEM, FTIR, TGDTA, and UV-Vis. spectroscopy. A 5 wt% TiO2 loading was identified as optimal and further enhanced with silver (Ag) nanoparticles to boost photocatalytic efficiency. The Ag/TiO2/PLA biofilm was fabricated via a compound pellet formulation process followed by blown film extrusion. Various compositions, with and without Ag, were systematically evaluated for photocatalytic performance. The novel customized hybrid air purifier developed in this study is designed to enhance indoor air purification efficiency by integrating Ag/TiO2/PLA biofilms into a controlled oxidation system. The air purification efficacy of the developed biofilm was evaluated through a controlled study on Staphylococcus aureus (S. aureus) removal under different treatment conditions: control, adsorption, photolysis, and photocatalytic oxidation. The impact of light intensity on photocatalytic efficiency was also examined. The photocatalytic oxidation of S. aureus was subjected to the first-order kinetic evaluation through mathematical modeling. Results demonstrated that the Ag/TiO2/PLA biofilm significantly enhances indoor air purification, providing a sustainable, scalable, and energy-efficient solution for microbial decontamination and pollutant removal. This innovative approach outperforms conventional adsorption, adsorption and photocatalytic oxidation systems, offering a promising pathway for improved indoor air quality.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
*Titanium/chemistry
*Biofilms
*Silver/chemistry
*Polyesters/chemistry
*Air Filters/microbiology
Staphylococcus aureus
Aerosols/chemistry
*Air Pollution, Indoor/prevention & control
Catalysis
Metal Nanoparticles/chemistry
RevDate: 2025-05-28
In Vitro Analysis of Interactions Between Staphylococcus aureus and Pseudomonas aeruginosa During Biofilm Formation.
Antibiotics (Basel, Switzerland), 14(5): pii:antibiotics14050504.
UNLABELLED: Staphylococcus aureus and Pseudomonas aeruginosa are classified as ESKAPE pathogens that present a significant challenge to treatment due to their increased resistance to a considerable number of antimicrobial agents. Background/Objective: Biofilms exacerbate treatment challenges by providing enhanced antimicrobial and environmental protection. Mixed-species biofilms further complicate treatment options through numerous complex interspecies interactions, leading to potentially severe adverse clinical outcomes.
METHODS: This study assessed the interaction between clinical S. aureus and P. aeruginosa isolates during biofilm formation using microplate biofilm formation assays, scanning electron microscopy, and confocal microscopy.
RESULTS: We identified a competitive relationship between P. aeruginosa and S. aureus, where both pathogens exhibited a reduction in biofilm formation during mixed-species biofilms compared with monocultures, although P. aeruginosa outcompeted S. aureus. Furthermore, we found that the cell-free conditioned media (CFCM) of P. aeruginosa significantly reduced the S. aureus biofilms. Using fractioned CFCM, we identified that the anti-staphylococcal activity of the >10 kDa fraction was almost identical to the non-fractioned CFCM. Our confocal microscopy results suggest that P. aeruginosa CFCM depolarize S. aureus membranes and reduces the biofilm burden.
CONCLUSIONS: These findings contribute to our understanding of the mechanisms underlying the interactions between these pathogens, suggesting that there is an antagonistic relationship between S. aureus and P. aeruginosa in a biofilm setting.
Additional Links: PMID-40426570
Publisher:
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40426570,
year = {2025},
author = {Scaffo, J and Lima, RD and Dobrotka, C and Ribeiro, TAN and Pereira, RFA and Sachs, D and Ferreira, RBR and Aguiar-Alves, F},
title = {In Vitro Analysis of Interactions Between Staphylococcus aureus and Pseudomonas aeruginosa During Biofilm Formation.},
journal = {Antibiotics (Basel, Switzerland)},
volume = {14},
number = {5},
pages = {},
doi = {10.3390/antibiotics14050504},
pmid = {40426570},
issn = {2079-6382},
support = {E-26/210.124/2022, E-26/210.505/2019; E-26/210.209/2018; E-26/010.002155/2019; SEI-260003/001213/2020; E-26/211.554/2019; E-26/010.001280/2016//Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro/ ; 001//University of Kansas/ ; 001//Lloyd L. Gregory School of Pharmacy - Palm Beach Atlantic University/ ; 001//Coordenação de Aperfeicoamento de Pessoal de Nível Superior/ ; },
abstract = {UNLABELLED: Staphylococcus aureus and Pseudomonas aeruginosa are classified as ESKAPE pathogens that present a significant challenge to treatment due to their increased resistance to a considerable number of antimicrobial agents. Background/Objective: Biofilms exacerbate treatment challenges by providing enhanced antimicrobial and environmental protection. Mixed-species biofilms further complicate treatment options through numerous complex interspecies interactions, leading to potentially severe adverse clinical outcomes.
METHODS: This study assessed the interaction between clinical S. aureus and P. aeruginosa isolates during biofilm formation using microplate biofilm formation assays, scanning electron microscopy, and confocal microscopy.
RESULTS: We identified a competitive relationship between P. aeruginosa and S. aureus, where both pathogens exhibited a reduction in biofilm formation during mixed-species biofilms compared with monocultures, although P. aeruginosa outcompeted S. aureus. Furthermore, we found that the cell-free conditioned media (CFCM) of P. aeruginosa significantly reduced the S. aureus biofilms. Using fractioned CFCM, we identified that the anti-staphylococcal activity of the >10 kDa fraction was almost identical to the non-fractioned CFCM. Our confocal microscopy results suggest that P. aeruginosa CFCM depolarize S. aureus membranes and reduces the biofilm burden.
CONCLUSIONS: These findings contribute to our understanding of the mechanisms underlying the interactions between these pathogens, suggesting that there is an antagonistic relationship between S. aureus and P. aeruginosa in a biofilm setting.},
}
RevDate: 2025-05-28
Essential Oils for Biofilm Control: Mechanisms, Synergies, and Translational Challenges in the Era of Antimicrobial Resistance.
Antibiotics (Basel, Switzerland), 14(5): pii:antibiotics14050503.
Biofilms, structured microbial consortia embedded in self-produced extracellular matrices, pose significant challenges across the medical, industrial, and environmental sectors due to their resistance to antimicrobial therapies and ability to evade the immune system. Their resilience is driven by multifaceted mechanisms, including matrix-mediated drug sequestration, metabolic dormancy, and quorum sensing (QS)-regulated virulence, which collectively sustain persistent infections and contribute to the amplification of antimicrobial resistance (AMR). This review critically examines the potential of plant-derived essential oils (EOs) as innovative agents for biofilm control. EOs exhibit broad-spectrum antibiofilm activity through multi-target mechanisms, including disrupting initial microbial adhesion, degrading extracellular polymeric substances (EPSs), suppressing QS pathways, and compromising membrane integrity. Their ability to act synergistically with conventional antimicrobials at sub-inhibitory concentrations enhances therapeutic efficacy while reducing the selection pressure for resistance. Despite their potential, EO applications face technical challenges, such as compositional variability due to botanical sources, formulation stability issues, and difficulties in standardization for large-scale production. Clinical translation is further complicated by biofilm stage- and strain-dependent efficacy, insufficient in vivo validation of therapeutic outcomes, and potential cytotoxicity at higher doses. These limitations underscore the need for optimized delivery systems, such as nanoencapsulation, to enhance bioavailability and mitigate adverse effects. Future strategies should include combinatorial approaches with antibiotics or EPS-degrading enzymes, advanced formulation technologies, and standardized protocols to bridge laboratory findings to clinical practice. By addressing these challenges, EOs hold transformative potential to mitigate biofilm-associated AMR, offering sustainable, multi-target alternatives for infection management and biofilm prevention in diverse contexts.
Additional Links: PMID-40426569
Publisher:
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40426569,
year = {2025},
author = {Touati, A and Mairi, A and Ibrahim, NA and Idres, T},
title = {Essential Oils for Biofilm Control: Mechanisms, Synergies, and Translational Challenges in the Era of Antimicrobial Resistance.},
journal = {Antibiotics (Basel, Switzerland)},
volume = {14},
number = {5},
pages = {},
doi = {10.3390/antibiotics14050503},
pmid = {40426569},
issn = {2079-6382},
support = {IMSIU-DDRSP2502//Deanship of Scientific Research at Imam Mohammad Ibn Saud Islamic University (IMSIU)/ ; },
abstract = {Biofilms, structured microbial consortia embedded in self-produced extracellular matrices, pose significant challenges across the medical, industrial, and environmental sectors due to their resistance to antimicrobial therapies and ability to evade the immune system. Their resilience is driven by multifaceted mechanisms, including matrix-mediated drug sequestration, metabolic dormancy, and quorum sensing (QS)-regulated virulence, which collectively sustain persistent infections and contribute to the amplification of antimicrobial resistance (AMR). This review critically examines the potential of plant-derived essential oils (EOs) as innovative agents for biofilm control. EOs exhibit broad-spectrum antibiofilm activity through multi-target mechanisms, including disrupting initial microbial adhesion, degrading extracellular polymeric substances (EPSs), suppressing QS pathways, and compromising membrane integrity. Their ability to act synergistically with conventional antimicrobials at sub-inhibitory concentrations enhances therapeutic efficacy while reducing the selection pressure for resistance. Despite their potential, EO applications face technical challenges, such as compositional variability due to botanical sources, formulation stability issues, and difficulties in standardization for large-scale production. Clinical translation is further complicated by biofilm stage- and strain-dependent efficacy, insufficient in vivo validation of therapeutic outcomes, and potential cytotoxicity at higher doses. These limitations underscore the need for optimized delivery systems, such as nanoencapsulation, to enhance bioavailability and mitigate adverse effects. Future strategies should include combinatorial approaches with antibiotics or EPS-degrading enzymes, advanced formulation technologies, and standardized protocols to bridge laboratory findings to clinical practice. By addressing these challenges, EOs hold transformative potential to mitigate biofilm-associated AMR, offering sustainable, multi-target alternatives for infection management and biofilm prevention in diverse contexts.},
}
RevDate: 2025-05-28
Heterogeneity of Biofilm Formation Among Staphylococcus aureus and Coagulase-Negative Staphylococcus Species in Clinically Relevant Intravenous Fat Emulsions.
Antibiotics (Basel, Switzerland), 14(5): pii:antibiotics14050484.
Background: Compared to soybean oil intravenous fat emulsion (SO-IFE), use of mixed-oil IFE (MO-IFE) is associated with reduced rates of catheter-related bloodstream infections caused by coagulase-negative Staphylococcus species (CoNS) in pediatric patients receiving parenteral nutrition. Methods: Using an in vitro biofilm model, this study aimed to assess the impact of IFEs on biofilm formation among Staphylococcus species. S. aureus, S. capitis, S. epidermidis, S. haemolyticus, S. hominis, and S. lugdunensis were cultivated as biofilms in media supplemented with SO-IFE, MO-IFE, or fish oil IFE (IFE). Biomass was quantified by the crystal violet method, and follow-up planktonic growth assays assessed antimicrobial effects of IFEs. Results: Compared to SO-IFE, MO-IFE and FO-IFE significantly inhibited biofilm formation of S. aureus but did not impact planktonic growth. Contrary to clinical data, CoNS biofilm formation was not impacted by any of the IFEs tested. S. aureus biofilm inhibition in IFEs was further investigated by comparing differences following growth in SO-IFE supplemented with capric acid, docosahexaenoic acid (DHA), or eicosapenaenoic acid (EPA) to concentrations matching those of MO-IFE. Capric acid supplementation was associated with significant reduction in biofilm formation compared to SO-IFE alone. However, this was attributed to a bactericidal effect based on follow-up planktonic growth assays. Conclusions: These results suggest that biofilm formation in S. aureus is variably impacted by fatty acid composition in clinically relevant IFEs, with capric acid exhibiting bactericidal activity against tested isolates.
Additional Links: PMID-40426550
Publisher:
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40426550,
year = {2025},
author = {Alvira-Arill, GR and Herrera, OR and Stultz, JS and Peters, BM},
title = {Heterogeneity of Biofilm Formation Among Staphylococcus aureus and Coagulase-Negative Staphylococcus Species in Clinically Relevant Intravenous Fat Emulsions.},
journal = {Antibiotics (Basel, Switzerland)},
volume = {14},
number = {5},
pages = {},
doi = {10.3390/antibiotics14050484},
pmid = {40426550},
issn = {2079-6382},
support = {R21AI153768//National Institutes of Allergy and Infectious Disease/ ; UTHSC collaborative seed grant//University of Tennessee Health Science Center College of Pharmacy/ ; Foundation Futures grant//American College of Clinical Pharmacy/ ; NA//University of Tennessee Health Science Center's Center for Pediatric Experimental Therapeutics/ ; R01AI177615//National Institutes of Allergy and Infectious Disease/ ; },
abstract = {Background: Compared to soybean oil intravenous fat emulsion (SO-IFE), use of mixed-oil IFE (MO-IFE) is associated with reduced rates of catheter-related bloodstream infections caused by coagulase-negative Staphylococcus species (CoNS) in pediatric patients receiving parenteral nutrition. Methods: Using an in vitro biofilm model, this study aimed to assess the impact of IFEs on biofilm formation among Staphylococcus species. S. aureus, S. capitis, S. epidermidis, S. haemolyticus, S. hominis, and S. lugdunensis were cultivated as biofilms in media supplemented with SO-IFE, MO-IFE, or fish oil IFE (IFE). Biomass was quantified by the crystal violet method, and follow-up planktonic growth assays assessed antimicrobial effects of IFEs. Results: Compared to SO-IFE, MO-IFE and FO-IFE significantly inhibited biofilm formation of S. aureus but did not impact planktonic growth. Contrary to clinical data, CoNS biofilm formation was not impacted by any of the IFEs tested. S. aureus biofilm inhibition in IFEs was further investigated by comparing differences following growth in SO-IFE supplemented with capric acid, docosahexaenoic acid (DHA), or eicosapenaenoic acid (EPA) to concentrations matching those of MO-IFE. Capric acid supplementation was associated with significant reduction in biofilm formation compared to SO-IFE alone. However, this was attributed to a bactericidal effect based on follow-up planktonic growth assays. Conclusions: These results suggest that biofilm formation in S. aureus is variably impacted by fatty acid composition in clinically relevant IFEs, with capric acid exhibiting bactericidal activity against tested isolates.},
}
RevDate: 2025-05-28
Antimicrobial Resistance Profile and Biofilm Formation of Listeria monocytogenes Isolated from Meat.
Antibiotics (Basel, Switzerland), 14(5): pii:antibiotics14050454.
INTRODUCTION: Listeria monocytogenes is the causative agent of listeriosis, a serious infectious disease with one of the highest case fatality rates among foodborne diseases affecting humans.
OBJECTIVES: This study investigated the prevalence, antimicrobial resistance pattern and biofilm production capacity of L. monocytogenes isolated in meats.
MATERIALS: A total of 75 samples were analyzed, including fresh meats and meat preparations, in Northern Portugal.
METHODS: The strains were identified using morphological and molecular methods. Antimicrobial resistance was determined using the Kirby-Bauer disk diffusion method, against a panel of 12 antibiotics and the presence of the respective antimicrobial resistance genes was investigated by polymerase chain reaction (PCR). The ability to form biofilms was evaluated by the microtiter biofilm assay.
RESULTS: The overall prevalence of L. monocytogenes among screened samples was 17.33%. The isolates were resistant to trimethoprim-sulfamethoxazole (85.71%), ciprofloxacin (38.10%), meropenem (33.33%), tetracycline and erythromycin (28.57%), rifampicin (23.81%), and kanamycin (14.29%). Six isolates (28.57%) exhibited a multidrug-resistance profile. All strains showed positive result for the virulence gene specific to listeriolysin O (hlyA). In the genotypic resistance analysis of the strains, the genes identified were tetK (23.81%), aadA, tetL, blaOXA-48 (14.29%), ermC, and msr(A/B) (4.76%). All isolates had the ability to form biofilms, with no significant differences in biofilm biomass production at 24 h and 48 h. Some of these strains showed a high capacity for biofilm production.
CONCLUSIONS: These findings raise public health concerns due to resistance to first-line antibiotics and the biofilm-forming capacity of these isolates, which pose risks to the food industry. Enhanced monitoring and surveillance are essential to guide public health strategies in order to mitigate the threat posed by L. monocytogenes in food.
Additional Links: PMID-40426521
Publisher:
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40426521,
year = {2025},
author = {Paiva, J and Silva, V and Poeta, P and Saraiva, C},
title = {Antimicrobial Resistance Profile and Biofilm Formation of Listeria monocytogenes Isolated from Meat.},
journal = {Antibiotics (Basel, Switzerland)},
volume = {14},
number = {5},
pages = {},
doi = {10.3390/antibiotics14050454},
pmid = {40426521},
issn = {2079-6382},
support = {UIDB/00772/2020//FCT/ ; },
abstract = {INTRODUCTION: Listeria monocytogenes is the causative agent of listeriosis, a serious infectious disease with one of the highest case fatality rates among foodborne diseases affecting humans.
OBJECTIVES: This study investigated the prevalence, antimicrobial resistance pattern and biofilm production capacity of L. monocytogenes isolated in meats.
MATERIALS: A total of 75 samples were analyzed, including fresh meats and meat preparations, in Northern Portugal.
METHODS: The strains were identified using morphological and molecular methods. Antimicrobial resistance was determined using the Kirby-Bauer disk diffusion method, against a panel of 12 antibiotics and the presence of the respective antimicrobial resistance genes was investigated by polymerase chain reaction (PCR). The ability to form biofilms was evaluated by the microtiter biofilm assay.
RESULTS: The overall prevalence of L. monocytogenes among screened samples was 17.33%. The isolates were resistant to trimethoprim-sulfamethoxazole (85.71%), ciprofloxacin (38.10%), meropenem (33.33%), tetracycline and erythromycin (28.57%), rifampicin (23.81%), and kanamycin (14.29%). Six isolates (28.57%) exhibited a multidrug-resistance profile. All strains showed positive result for the virulence gene specific to listeriolysin O (hlyA). In the genotypic resistance analysis of the strains, the genes identified were tetK (23.81%), aadA, tetL, blaOXA-48 (14.29%), ermC, and msr(A/B) (4.76%). All isolates had the ability to form biofilms, with no significant differences in biofilm biomass production at 24 h and 48 h. Some of these strains showed a high capacity for biofilm production.
CONCLUSIONS: These findings raise public health concerns due to resistance to first-line antibiotics and the biofilm-forming capacity of these isolates, which pose risks to the food industry. Enhanced monitoring and surveillance are essential to guide public health strategies in order to mitigate the threat posed by L. monocytogenes in food.},
}
RevDate: 2025-05-27
Novel yellow light-responsive SnO2/SnS2 piezo-photocatalysts with excellent performances for tooth whitening and biofilm eradication.
Journal of materials chemistry. B [Epub ahead of print].
Oral problems caused by pathogens and tooth discoloration have posed great threats to public health in recent years. Timely killing of cariogenic bacteria and removing surface pigments are the key points to treat yellow teeth to restore healthy whitening. Piezo-photocatalysis has been proved to be an effective strategy for treating yellow teeth. However, few effective and safe nanomaterials have been developed to address this issue in the oral field. Herein, yellow light-responsive SnO2/SnS2 heterostructures are proposed for piezo-photocatalytic biofilm eradication and tooth whitening for the first time. Initially, XRD and HRTEM results experimentally verified the formation of SnO2/SnS2 heterostructures. Further, UV-vis DRS spectra indicated that the absorbance in the visible region was effectively improved after the formation of SnO2/SnS2 heterostructures. Subsequently, yellow light with excellent biocompatibility was combined with ultrasonic treatment to explore the piezo-photocatalytic performances of SnO2/SnS2 for tooth whitening and biofilm removal. Results demonstrated that the SnO2/SnS2 heterostructure prepared with a TAA : SnO2 molar ratio of 1 : 1 for 3 h exhibited the best piezo-photocatalytic performance. The degradation efficiency for the food colorant indigo carmine reached 94.12%, which was much higher than that of single SnS2 (48.31%), single SnO2 (near zero) and treating with only irradiation (63.03%) and only ultrasonic (79.41%). Simultaneously, the heterostructures exhibited excellent piezo-photocatalytic tooth whitening effect on stained teeth. Moreover, the SnO2/SnS2 heterojunctions exhibited excellent piezo-photocatalytic performances in bacteria killing and biofilm removal, and the antibacterial efficiencies reached 77.3% and 56.5% for planktonic S. mutans and biofilms, respectively. In addition, synergistic treating process of SnO2/SnS2 heterostructures resulted in excellent biocompatibility, including much less cytotoxicity and negligible enamel damage. In-depth mechanism investigation indicated that the improved piezo-photocatalytic performances were due to the increased carrier separation efficiency and ROS productivity of SnO2/SnS2 heterostructures, demonstrating the great potential of SnO2/SnS2 heterostructures for future dental care field.
Additional Links: PMID-40423942
Publisher:
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40423942,
year = {2025},
author = {Song, J and Yuan, S and Liu, S and Wang, Y and Yang, B and Ji, L and He, L and Liu, S},
title = {Novel yellow light-responsive SnO2/SnS2 piezo-photocatalysts with excellent performances for tooth whitening and biofilm eradication.},
journal = {Journal of materials chemistry. B},
volume = {},
number = {},
pages = {},
doi = {10.1039/d5tb00407a},
pmid = {40423942},
issn = {2050-7518},
abstract = {Oral problems caused by pathogens and tooth discoloration have posed great threats to public health in recent years. Timely killing of cariogenic bacteria and removing surface pigments are the key points to treat yellow teeth to restore healthy whitening. Piezo-photocatalysis has been proved to be an effective strategy for treating yellow teeth. However, few effective and safe nanomaterials have been developed to address this issue in the oral field. Herein, yellow light-responsive SnO2/SnS2 heterostructures are proposed for piezo-photocatalytic biofilm eradication and tooth whitening for the first time. Initially, XRD and HRTEM results experimentally verified the formation of SnO2/SnS2 heterostructures. Further, UV-vis DRS spectra indicated that the absorbance in the visible region was effectively improved after the formation of SnO2/SnS2 heterostructures. Subsequently, yellow light with excellent biocompatibility was combined with ultrasonic treatment to explore the piezo-photocatalytic performances of SnO2/SnS2 for tooth whitening and biofilm removal. Results demonstrated that the SnO2/SnS2 heterostructure prepared with a TAA : SnO2 molar ratio of 1 : 1 for 3 h exhibited the best piezo-photocatalytic performance. The degradation efficiency for the food colorant indigo carmine reached 94.12%, which was much higher than that of single SnS2 (48.31%), single SnO2 (near zero) and treating with only irradiation (63.03%) and only ultrasonic (79.41%). Simultaneously, the heterostructures exhibited excellent piezo-photocatalytic tooth whitening effect on stained teeth. Moreover, the SnO2/SnS2 heterojunctions exhibited excellent piezo-photocatalytic performances in bacteria killing and biofilm removal, and the antibacterial efficiencies reached 77.3% and 56.5% for planktonic S. mutans and biofilms, respectively. In addition, synergistic treating process of SnO2/SnS2 heterostructures resulted in excellent biocompatibility, including much less cytotoxicity and negligible enamel damage. In-depth mechanism investigation indicated that the improved piezo-photocatalytic performances were due to the increased carrier separation efficiency and ROS productivity of SnO2/SnS2 heterostructures, demonstrating the great potential of SnO2/SnS2 heterostructures for future dental care field.},
}
RevDate: 2025-05-27
CmpDate: 2025-05-27
Exploring evolutionary perspectives and antibiogram analysis of biofilm-forming Staphylococcus aureus in goat mastitis.
Veterinary research communications, 49(4):209.
Biofilm formation plays a key role in developing antimicrobial resistance in Staphylococcus aureus (S. aureus) and is thus a major virulence factor responsible for persistent intramammary infections and subclinical mastitis in goats. The current study investigated the prevalence and molecular characterization of biofilm-forming S. aureus isolated from goat mastitis, the associated risk factors, and comparative antibiogram profiling. A total of 768 milk samples were conveniently collected from farms dairy goats in three districts of Pakistan Multan, Bahawalpur, and Rahim Yar Khan. The results revealed a molecular prevalence (presence of nuc gene) of 206/426 (48.37%) for S. aureus in milk samples from goats. The risk factors analysis showed that age group, water availability, previous mastitis history, hygienic measures during milking, teat lesion, and veterinary services posed significant associations with S. aureus intramammary infections in goats. The prevalence of biofilm production by phenotypic methods i.e. Congo Red agar and Microtitre plate were recorded to be 36.90% and 27.67% respectively. In comparison, the genotypic confirmation was done by the presence of the icaA gene and was found to be 55.34%. The phylogenetic analysis of the icaA gene revealed high homology between sequences of study isolates and the isolates of other countries like India, Egypt, Japan Kenya, the USA, and China. The S. aureus subjected to the Kirby-Bauer disc diffusion method revealed the highest resistance to cefoxitin and oxytetracycline followed by gentamycin, amikacin, trimethoprim + sulphamethoxazole, and vancomycin. There was a slight variation among the resistant profile of biofilm and non-biofilm producing S. aureus strains against antimicrobial agents. Out of 206, 31.07% (64/206) tested isolates exhibited resistance to three or more antibiotics concurrently, categorizing them as multiple drug resistant (MDR) with multiple antibiotic resistance index greater than 0.2. The study concluded that biofilm-producing S. aureus is prevalent in dairy goats of different breeds, including Beetal, Teddi, Barbari, and Makhi-cheeni, across various lactation stages (early, mid, and late), regardless of milk collection times in Pakistan of Pakistan with risk to the udder health and milk quality. Moreover, the biofilm formation may be associated with multidrug resistance of study isolates.
Additional Links: PMID-40423849
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40423849,
year = {2025},
author = {Javed, MU and Ijaz, M and Ahmed, A and Rasheed, H and Jabir, AA and Batool, M and Shahid, K and Ali, A and Talha, M},
title = {Exploring evolutionary perspectives and antibiogram analysis of biofilm-forming Staphylococcus aureus in goat mastitis.},
journal = {Veterinary research communications},
volume = {49},
number = {4},
pages = {209},
pmid = {40423849},
issn = {1573-7446},
mesh = {Animals ; Goats ; *Biofilms/growth & development/drug effects ; *Goat Diseases/microbiology/epidemiology ; Female ; *Staphylococcus aureus/physiology/drug effects/genetics ; *Staphylococcal Infections/veterinary/microbiology/epidemiology ; Pakistan/epidemiology ; *Mastitis/veterinary/microbiology/epidemiology ; Anti-Bacterial Agents/pharmacology ; Microbial Sensitivity Tests/veterinary ; Milk/microbiology ; Phylogeny ; Risk Factors ; Prevalence ; },
abstract = {Biofilm formation plays a key role in developing antimicrobial resistance in Staphylococcus aureus (S. aureus) and is thus a major virulence factor responsible for persistent intramammary infections and subclinical mastitis in goats. The current study investigated the prevalence and molecular characterization of biofilm-forming S. aureus isolated from goat mastitis, the associated risk factors, and comparative antibiogram profiling. A total of 768 milk samples were conveniently collected from farms dairy goats in three districts of Pakistan Multan, Bahawalpur, and Rahim Yar Khan. The results revealed a molecular prevalence (presence of nuc gene) of 206/426 (48.37%) for S. aureus in milk samples from goats. The risk factors analysis showed that age group, water availability, previous mastitis history, hygienic measures during milking, teat lesion, and veterinary services posed significant associations with S. aureus intramammary infections in goats. The prevalence of biofilm production by phenotypic methods i.e. Congo Red agar and Microtitre plate were recorded to be 36.90% and 27.67% respectively. In comparison, the genotypic confirmation was done by the presence of the icaA gene and was found to be 55.34%. The phylogenetic analysis of the icaA gene revealed high homology between sequences of study isolates and the isolates of other countries like India, Egypt, Japan Kenya, the USA, and China. The S. aureus subjected to the Kirby-Bauer disc diffusion method revealed the highest resistance to cefoxitin and oxytetracycline followed by gentamycin, amikacin, trimethoprim + sulphamethoxazole, and vancomycin. There was a slight variation among the resistant profile of biofilm and non-biofilm producing S. aureus strains against antimicrobial agents. Out of 206, 31.07% (64/206) tested isolates exhibited resistance to three or more antibiotics concurrently, categorizing them as multiple drug resistant (MDR) with multiple antibiotic resistance index greater than 0.2. The study concluded that biofilm-producing S. aureus is prevalent in dairy goats of different breeds, including Beetal, Teddi, Barbari, and Makhi-cheeni, across various lactation stages (early, mid, and late), regardless of milk collection times in Pakistan of Pakistan with risk to the udder health and milk quality. Moreover, the biofilm formation may be associated with multidrug resistance of study isolates.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
Animals
Goats
*Biofilms/growth & development/drug effects
*Goat Diseases/microbiology/epidemiology
Female
*Staphylococcus aureus/physiology/drug effects/genetics
*Staphylococcal Infections/veterinary/microbiology/epidemiology
Pakistan/epidemiology
*Mastitis/veterinary/microbiology/epidemiology
Anti-Bacterial Agents/pharmacology
Microbial Sensitivity Tests/veterinary
Milk/microbiology
Phylogeny
Risk Factors
Prevalence
RevDate: 2025-05-27
CmpDate: 2025-05-27
Metabolite-Driven Modulation of Biofilm Formation in Shewanella: Insights from Shewanella sp. Pdp11 Extracellular Products.
Microbial ecology, 88(1):55.
Biofilm formation is a survival strategy for bacteria, contributing to their persistence in natural and industrial environments. In this study, we investigated the ability of extracellular products (ECPs) produced by the probiotic strain Shewanella sp. Pdp11 under different culture conditions to inhibit biofilm formation in pathogenic and environmental Shewanella strains. ECPs from specific culture conditions altered biofilm formation in several Shewanella strains, with Shewanella hafniensis P14 displaying the highest sensitivity. Metabolomic analysis of the ECPs identified glycogen as a key metabolite associated with biofilm inhibition. Further genomic analysis of S. hafniensis P14 revealed an interruption in its glycogen synthesis pathway, suggesting a dependency on external glycogen-related metabolites for biofilm development. These findings demonstrate that Shewanella sp. Pdp11 ECPs can modify biofilm formation across multiple Shewanella strains, particularly in S. hafniensis P14 through glycogen-associated mechanisms.
Additional Links: PMID-40423845
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40423845,
year = {2025},
author = {Pérez-Gómez, O and Domínguez-Maqueda, M and García-Márquez, J and Moriñigo, MÁ and Tapia-Paniagua, ST},
title = {Metabolite-Driven Modulation of Biofilm Formation in Shewanella: Insights from Shewanella sp. Pdp11 Extracellular Products.},
journal = {Microbial ecology},
volume = {88},
number = {1},
pages = {55},
pmid = {40423845},
issn = {1432-184X},
support = {PID2020-113637RB-C21//Ministerio de Ciencia e Innovación/ ; PID2020-113637RB-C21//Ministerio de Ciencia e Innovación/ ; PID2020-113637RB-C21//Ministerio de Ciencia e Innovación/ ; PID2020-113637RB-C21//Ministerio de Ciencia e Innovación/ ; PID2020-113637RB-C21//Ministerio de Ciencia e Innovación/ ; },
mesh = {*Shewanella/metabolism/physiology/genetics ; *Biofilms/growth & development/drug effects ; Glycogen/metabolism ; },
abstract = {Biofilm formation is a survival strategy for bacteria, contributing to their persistence in natural and industrial environments. In this study, we investigated the ability of extracellular products (ECPs) produced by the probiotic strain Shewanella sp. Pdp11 under different culture conditions to inhibit biofilm formation in pathogenic and environmental Shewanella strains. ECPs from specific culture conditions altered biofilm formation in several Shewanella strains, with Shewanella hafniensis P14 displaying the highest sensitivity. Metabolomic analysis of the ECPs identified glycogen as a key metabolite associated with biofilm inhibition. Further genomic analysis of S. hafniensis P14 revealed an interruption in its glycogen synthesis pathway, suggesting a dependency on external glycogen-related metabolites for biofilm development. These findings demonstrate that Shewanella sp. Pdp11 ECPs can modify biofilm formation across multiple Shewanella strains, particularly in S. hafniensis P14 through glycogen-associated mechanisms.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
*Shewanella/metabolism/physiology/genetics
*Biofilms/growth & development/drug effects
Glycogen/metabolism
RevDate: 2025-05-27
Breaking Biofilm Barriers: Using CATH-ICG-Loaded Bilayer Dissolving Microneedle-Assisted Photodynamic Therapy for Deep Skin Candidiasis.
Molecular pharmaceutics [Epub ahead of print].
Deep skin fungal infections, particularly biofilm-associated Candida albicans (C. albicans), pose significant clinical challenges due to their resistance to conventional antifungal therapies. The stratum corneum acts as a barrier to high molecular weight drugs, limiting the penetration of systemic and topical antifungal agents. In this study, we explored a transdermal delivery system utilizing novel Cathelicidin─HcCATH-KL30 (CATH)-loaded dissolving microneedles (DMNs) for the treatment of deep dermal C. albicans biofilm infections. Preliminary evaluations demonstrated that CATH exhibited potent antifungal activity against nonfilamentous and filamentous C. albicans but was ineffective against biofilm-embedded Candida, suggesting biofilm penetration limitations. To enhance its efficacy, we integrated indocyanine green into DMNs and applied photodynamic therapy (PDT) using near-infrared (NIR) irradiation. The generated reactive oxygen species disrupted the biofilm matrix, allowing a deeper penetration of CATH for enhanced antifungal activity. Results from in vitro, ex vivo, and in vivo models demonstrated a significant reduction (∼94%) in fungal burden with CATH-ICG-DMNs following NIR irradiation, highlighting a synergistic effect. Findings of the study were mechanistically validated through qRT-PCR and propodeum iodide staining, which were in accordance with the proposed hypothesis. The current research work for the first time explored the novel antimicrobial peptide from a drug delivery platform in order to investigate its potential. This study establishes a promising microneedle-based PDT strategy for combating deep skin fungal infections, overcoming biofilm-mediated resistance and enhancing antifungal therapy efficacy.
Additional Links: PMID-40423575
Publisher:
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40423575,
year = {2025},
author = {Hussain, Y and Dormocara, A and Li, H and Li, C and Khan, MK and Ma, Y and Leng, G and Wang, Y and You, BG and Cui, JH},
title = {Breaking Biofilm Barriers: Using CATH-ICG-Loaded Bilayer Dissolving Microneedle-Assisted Photodynamic Therapy for Deep Skin Candidiasis.},
journal = {Molecular pharmaceutics},
volume = {},
number = {},
pages = {},
doi = {10.1021/acs.molpharmaceut.5c00367},
pmid = {40423575},
issn = {1543-8392},
abstract = {Deep skin fungal infections, particularly biofilm-associated Candida albicans (C. albicans), pose significant clinical challenges due to their resistance to conventional antifungal therapies. The stratum corneum acts as a barrier to high molecular weight drugs, limiting the penetration of systemic and topical antifungal agents. In this study, we explored a transdermal delivery system utilizing novel Cathelicidin─HcCATH-KL30 (CATH)-loaded dissolving microneedles (DMNs) for the treatment of deep dermal C. albicans biofilm infections. Preliminary evaluations demonstrated that CATH exhibited potent antifungal activity against nonfilamentous and filamentous C. albicans but was ineffective against biofilm-embedded Candida, suggesting biofilm penetration limitations. To enhance its efficacy, we integrated indocyanine green into DMNs and applied photodynamic therapy (PDT) using near-infrared (NIR) irradiation. The generated reactive oxygen species disrupted the biofilm matrix, allowing a deeper penetration of CATH for enhanced antifungal activity. Results from in vitro, ex vivo, and in vivo models demonstrated a significant reduction (∼94%) in fungal burden with CATH-ICG-DMNs following NIR irradiation, highlighting a synergistic effect. Findings of the study were mechanistically validated through qRT-PCR and propodeum iodide staining, which were in accordance with the proposed hypothesis. The current research work for the first time explored the novel antimicrobial peptide from a drug delivery platform in order to investigate its potential. This study establishes a promising microneedle-based PDT strategy for combating deep skin fungal infections, overcoming biofilm-mediated resistance and enhancing antifungal therapy efficacy.},
}
RevDate: 2025-05-27
In Situ Eradication of Mature Oral Biofilm on Titanium Implant Surfaces Using Cold Atmospheric Plasma.
Dentistry journal, 13(5):.
Objective: This study evaluated the effectiveness of a new cold atmospheric plasma device (AmbiJet) for eradicating mature oral biofilm on titanium implant surfaces, aiming to improve decontamination methods for the treatment of peri-implant infections. Material and methods: Mature oral biofilms were grown on titanium disks placed in participants' mouths. These disks were divided into control and plasma treatment groups. The AmbiJet device delivered plasma directly to the implant surface for 3 min per 20 mm[2], utilizing the applicator nozzle and implant as electrodes. Biofilm reduction was quantified by counting colony-forming units (CFUs). Results: Cold plasma treatment rendered approximately 90% of samples bacteria-free. A > 6-log10 reduction (≈99.9999%) in bacterial load was achieved in 30% of samples, with an overall average reduction of 4.9-log10 across all treated samples. The temperature during treatment remained below 40 °C. Conclusions: Within the study's limitations, cold atmospheric plasma effectively eradicates mature oral biofilm on titanium surfaces. This high disinfection efficacy is likely due to the combined action of reactive species and electrical phenomena, which does not cause significant temperature increases.
Additional Links: PMID-40422630
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40422630,
year = {2025},
author = {Altenburger, MJ and Bergmann, ME and Ledernez, LA and Romanos, G},
title = {In Situ Eradication of Mature Oral Biofilm on Titanium Implant Surfaces Using Cold Atmospheric Plasma.},
journal = {Dentistry journal},
volume = {13},
number = {5},
pages = {},
pmid = {40422630},
issn = {2304-6767},
support = {03VP06620//German Federal Ministry for Education and Research (BMBF)/ ; xxx//Open Access Publication Fund of the University of Freiburg/ ; },
abstract = {Objective: This study evaluated the effectiveness of a new cold atmospheric plasma device (AmbiJet) for eradicating mature oral biofilm on titanium implant surfaces, aiming to improve decontamination methods for the treatment of peri-implant infections. Material and methods: Mature oral biofilms were grown on titanium disks placed in participants' mouths. These disks were divided into control and plasma treatment groups. The AmbiJet device delivered plasma directly to the implant surface for 3 min per 20 mm[2], utilizing the applicator nozzle and implant as electrodes. Biofilm reduction was quantified by counting colony-forming units (CFUs). Results: Cold plasma treatment rendered approximately 90% of samples bacteria-free. A > 6-log10 reduction (≈99.9999%) in bacterial load was achieved in 30% of samples, with an overall average reduction of 4.9-log10 across all treated samples. The temperature during treatment remained below 40 °C. Conclusions: Within the study's limitations, cold atmospheric plasma effectively eradicates mature oral biofilm on titanium surfaces. This high disinfection efficacy is likely due to the combined action of reactive species and electrical phenomena, which does not cause significant temperature increases.},
}
RevDate: 2025-05-27
Molecular characteristics of antimicrobial resistance and biofilm formation of bloodstream infection pathogens isolated from pediatric patients in Ukraine.
IJID regions, 15:100646.
OBJECTIVES: To determine antimicrobial resistance and biofilm-associated genes among clinical isolates of bloodstream infection pathogens in Ukraine.
METHODS: A total of 35 clinical strains of Klebsiella pneumonia and 50 clinical strains of Staphylococcus spp. were isolated from patients from Ukrainian tertiary-level children`s hospitals during 2023 with bloodstream infections including central venous catheter-associated infections. Antimicrobial susceptibility testing was conducted following the European Committee on Antimicrobial Susceptibility Testing methodology. Capacity to form biofilms was assessed using a microtiter plate assay. Amplification of the variable resistance genes (blaNDM-1, blaKPC, OXA-48, blaCTX-M-1, blaTEM, qnrB, gyrA, mecA) and biofilm-associated genes (clfA, fnbpA, icaA, fimH, mrkA, matBecp) was performed by polymerase chain reaction.
RESULTS: |Overall, 96% (n = 46/50) of all Staphylococcus spp. strains expressed icaA, 94% (n = 47/50) of strains expressed fnbpA and 92% (n = 45/50) expressed clfA genes. In total, 32% (n = 16/50) of strains were resistant to methicillin, and all of the strains expressed mecA. All K. pneumoniae strains expressed matBecp, and 97% (n = 34/35) expressed fimH and mrkA genes. All of K. pneumonia were resistant to third-generation cephalosporins, 74.3% (n = 25/35) of isolates expressed CTX and 80% (n = 28/35) expressed blaTEM gene, 71.4% (n = 25/35) strains expressed both genes. In total, 80% (n = 28/35) of K. pneumoniae were resistant to carbapenems, 60.7% (n = 17/28) expressed blaNDM-1, 64.3% (n = 18/28) expressed OXA-48 and all 28 strains expressed blaKPC. A total of 90% (n = 18/20) of K. pneumoniae were resistant to fluoroquinolones, 88.9% (n = 16/18) expressed qnrB and none of the isolates expressed gyrA gene.
CONCLUSIONS: Very high prevalence of genes associated with biofilm formation was observed in clinical isolates of Staphylococcus spp. and K. pneumoniae. High-level resistance to all antimicrobials was observed in K. pneumoniae strains.
Additional Links: PMID-40417591
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40417591,
year = {2025},
author = {Vodianyk, A and Poniatovskiy, V and Shyrobokov, V},
title = {Molecular characteristics of antimicrobial resistance and biofilm formation of bloodstream infection pathogens isolated from pediatric patients in Ukraine.},
journal = {IJID regions},
volume = {15},
number = {},
pages = {100646},
pmid = {40417591},
issn = {2772-7076},
abstract = {OBJECTIVES: To determine antimicrobial resistance and biofilm-associated genes among clinical isolates of bloodstream infection pathogens in Ukraine.
METHODS: A total of 35 clinical strains of Klebsiella pneumonia and 50 clinical strains of Staphylococcus spp. were isolated from patients from Ukrainian tertiary-level children`s hospitals during 2023 with bloodstream infections including central venous catheter-associated infections. Antimicrobial susceptibility testing was conducted following the European Committee on Antimicrobial Susceptibility Testing methodology. Capacity to form biofilms was assessed using a microtiter plate assay. Amplification of the variable resistance genes (blaNDM-1, blaKPC, OXA-48, blaCTX-M-1, blaTEM, qnrB, gyrA, mecA) and biofilm-associated genes (clfA, fnbpA, icaA, fimH, mrkA, matBecp) was performed by polymerase chain reaction.
RESULTS: |Overall, 96% (n = 46/50) of all Staphylococcus spp. strains expressed icaA, 94% (n = 47/50) of strains expressed fnbpA and 92% (n = 45/50) expressed clfA genes. In total, 32% (n = 16/50) of strains were resistant to methicillin, and all of the strains expressed mecA. All K. pneumoniae strains expressed matBecp, and 97% (n = 34/35) expressed fimH and mrkA genes. All of K. pneumonia were resistant to third-generation cephalosporins, 74.3% (n = 25/35) of isolates expressed CTX and 80% (n = 28/35) expressed blaTEM gene, 71.4% (n = 25/35) strains expressed both genes. In total, 80% (n = 28/35) of K. pneumoniae were resistant to carbapenems, 60.7% (n = 17/28) expressed blaNDM-1, 64.3% (n = 18/28) expressed OXA-48 and all 28 strains expressed blaKPC. A total of 90% (n = 18/20) of K. pneumoniae were resistant to fluoroquinolones, 88.9% (n = 16/18) expressed qnrB and none of the isolates expressed gyrA gene.
CONCLUSIONS: Very high prevalence of genes associated with biofilm formation was observed in clinical isolates of Staphylococcus spp. and K. pneumoniae. High-level resistance to all antimicrobials was observed in K. pneumoniae strains.},
}
RevDate: 2025-05-27
Influence of nitrate-containing arugula juice on nitrate-reducing oral bacteria and periodontopathogens in smokers' biofilm.
Frontiers in dental medicine, 6:1545479.
Green leafy vegetables such as arugula are rich in nitrates that support oral health, yet their effects on oral microbial balance, especially in smokers, remain unclear. This study evaluated the survival and activity of nitrate-reducing bacteria (NRB; Veillonella spp. and Rothia spp.) in biofilm exposed to nitrate-containing arugula juice (3.25 or 6.25 μM). The proportions of NRB were compared with periodontopathogens (Porphyromonas gingivalis and Fusobacterium nucleatum). Using quantitative real-time PCR (qPCR), we assessed bacterial survival and transcription of nitrate reductase genes (narG and napA) in biofilm from smokers and non-smokers. The results revealed that nitrate-containing arugula juice increased NRB bacteria abundance while reducing periodontopathogen growth. A higher level of nitrate (6.25 μM) increased nitrate reductase expression. Prolonged exposure (9 h) sustained the growth-promoting effect on Rothia spp. These results suggest that non-smokers have more nitrate-reducing bacteria in their biofilm, which promotes oral microbial balance. Thus, smokers might be advised to consume nitrate-containing arugula juice to promote NRB, which may have health benefits.
Additional Links: PMID-40416551
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40416551,
year = {2025},
author = {Bachtiar, BM and Rieuwpassa, IE and Susilowati, H and Indrawati, R and Theodorea, CF and Fath, T and Bachtiar, EW},
title = {Influence of nitrate-containing arugula juice on nitrate-reducing oral bacteria and periodontopathogens in smokers' biofilm.},
journal = {Frontiers in dental medicine},
volume = {6},
number = {},
pages = {1545479},
pmid = {40416551},
issn = {2673-4915},
abstract = {Green leafy vegetables such as arugula are rich in nitrates that support oral health, yet their effects on oral microbial balance, especially in smokers, remain unclear. This study evaluated the survival and activity of nitrate-reducing bacteria (NRB; Veillonella spp. and Rothia spp.) in biofilm exposed to nitrate-containing arugula juice (3.25 or 6.25 μM). The proportions of NRB were compared with periodontopathogens (Porphyromonas gingivalis and Fusobacterium nucleatum). Using quantitative real-time PCR (qPCR), we assessed bacterial survival and transcription of nitrate reductase genes (narG and napA) in biofilm from smokers and non-smokers. The results revealed that nitrate-containing arugula juice increased NRB bacteria abundance while reducing periodontopathogen growth. A higher level of nitrate (6.25 μM) increased nitrate reductase expression. Prolonged exposure (9 h) sustained the growth-promoting effect on Rothia spp. These results suggest that non-smokers have more nitrate-reducing bacteria in their biofilm, which promotes oral microbial balance. Thus, smokers might be advised to consume nitrate-containing arugula juice to promote NRB, which may have health benefits.},
}
RevDate: 2025-05-27
Detection of Extended-Spectrum β-Lactamases, Metallo-β-Lactamases, Antimicrobial Resistance Profiles, and Biofilm-Forming Capacity in Pseudomonas aeruginosa Strains Recovered From Dogs With Otitis Externa in Italy.
Veterinary medicine international, 2025:5566151.
Pseudomonas aeruginosa is considered the second major causative agent of otitis externa in dogs, after Staphylococcus pseudintermedius. This study aimed to evaluate the antimicrobial resistance profiles and to detect the extended-spectrum β-lactamase (ESBL) and metallo-β-lactamase (MBL) genes in Pseudomonas aeruginosa (P. aeruginosa). Precisely, seventeen P. aeruginosa strains, recovered from auricular specimens of dogs affected by otitis externa, were identified by MALDI-TOF MS. Antimicrobial susceptibility testing was carried out against eleven clinically relevant antimicrobials using the Kirby Bauer disk diffusion method on Mueller Hinton agar plates. The PCR assay was performed to detect ESBL bla CTX-M , bla TEM , bla SHV , bla PER , and MBL bla IMP , bla OXA-48, bla VIM , bla NDM , bla GES genes. The results showed that P. aeruginosa isolates had a phenotypic resistance value of 100% to ceftazidime, imipenem, and meropenem, followed by piperacillin-tazobactam, sulfamethoxazole-trimethoprim (94%), and aztreonam (88%). An alarming result was represented by the high prevalence of multidrug-resistant strains with 100% of the total isolates. The most common ESBL-genotype combination was bla PER + bla SHV (29.4%). Thirteen isolates (76.5%) carried together bla VIM + bla GES genes, which resulted to be the most common MBL-genotype combination. All the isolates harboring ESBL and MBL genes were biofilm producers, evaluated by the crystal violet-based assay and PCR. Precisely, 76.5% were strong biofilm producers, and 23.5% resulted in being moderate producers. No relationship was observed between strong or moderate biofilm producers and numerical variability of ESBL and MBL genes. This study revealed worrying antimicrobial resistance profiles of P. aeruginosa-associated canine otitis externa, considering also the zoonotic potential of this pathogen.
Additional Links: PMID-40415870
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40415870,
year = {2025},
author = {Nocera, FP and Chiaromonte, A and Schena, R and Pizzano, F and Arslan, S and Pedicini, C and De Martino, L},
title = {Detection of Extended-Spectrum β-Lactamases, Metallo-β-Lactamases, Antimicrobial Resistance Profiles, and Biofilm-Forming Capacity in Pseudomonas aeruginosa Strains Recovered From Dogs With Otitis Externa in Italy.},
journal = {Veterinary medicine international},
volume = {2025},
number = {},
pages = {5566151},
pmid = {40415870},
issn = {2090-8113},
abstract = {Pseudomonas aeruginosa is considered the second major causative agent of otitis externa in dogs, after Staphylococcus pseudintermedius. This study aimed to evaluate the antimicrobial resistance profiles and to detect the extended-spectrum β-lactamase (ESBL) and metallo-β-lactamase (MBL) genes in Pseudomonas aeruginosa (P. aeruginosa). Precisely, seventeen P. aeruginosa strains, recovered from auricular specimens of dogs affected by otitis externa, were identified by MALDI-TOF MS. Antimicrobial susceptibility testing was carried out against eleven clinically relevant antimicrobials using the Kirby Bauer disk diffusion method on Mueller Hinton agar plates. The PCR assay was performed to detect ESBL bla CTX-M , bla TEM , bla SHV , bla PER , and MBL bla IMP , bla OXA-48, bla VIM , bla NDM , bla GES genes. The results showed that P. aeruginosa isolates had a phenotypic resistance value of 100% to ceftazidime, imipenem, and meropenem, followed by piperacillin-tazobactam, sulfamethoxazole-trimethoprim (94%), and aztreonam (88%). An alarming result was represented by the high prevalence of multidrug-resistant strains with 100% of the total isolates. The most common ESBL-genotype combination was bla PER + bla SHV (29.4%). Thirteen isolates (76.5%) carried together bla VIM + bla GES genes, which resulted to be the most common MBL-genotype combination. All the isolates harboring ESBL and MBL genes were biofilm producers, evaluated by the crystal violet-based assay and PCR. Precisely, 76.5% were strong biofilm producers, and 23.5% resulted in being moderate producers. No relationship was observed between strong or moderate biofilm producers and numerical variability of ESBL and MBL genes. This study revealed worrying antimicrobial resistance profiles of P. aeruginosa-associated canine otitis externa, considering also the zoonotic potential of this pathogen.},
}
RevDate: 2025-05-26
Thienoacene-Based Conjugated Oligoelectrolytes for Membrane-Targeting Antimicrobial Approaches: Synergistic Biofilm Eradication and Antimicrobial Resistance Reversal.
ACS applied materials & interfaces [Epub ahead of print].
Membrane-targeting antimicrobials represent a promising class of materials to combat the escalating issue of antimicrobial resistance. Herein, we report a series of membrane-targeting conjugated oligoelectrolytes (COE-nT) featuring thienoacene moieties as π-conjugated cores, designed for tackling antimicrobial resistance. COE-nT exhibited higher activity against Gram-positive bacteria compared to Gram-negative bacteria, with no intrinsic resistance observed in either drug-resistant strain. Notably, a reduction in the π-conjugated length of COE-nT correlated with an increase in membrane permeability and toxicity toward cells and animals. Moreover, COE-nT demonstrated synergistic effects with commercial antibiotics against drug-resistant strains and restored susceptibility to ribosome-targeting antibiotics, such as clindamycin and erythromycin. To illustrate their synergistic potential, the combination of COE-4T and mupirocin was employed to treat methicillin-resistant Staphylococcus aureus infections in a murine wound model, resulting in significant biofilm eradication and enhanced antimicrobial efficacy. This new series of thienoacene-based COEs expands the antimicrobial COEs library with defined structure-activity relationship profiles and demonstrates its potential as a powerful adjunctive therapy for overcoming antimicrobial resistance.
Additional Links: PMID-40415377
Publisher:
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40415377,
year = {2025},
author = {Chen, L and Wang, L and Mao, Y and Hu, H and Xu, L and Shen, W and Wang, B and Xiao, J and Zhang, H and Nie, C},
title = {Thienoacene-Based Conjugated Oligoelectrolytes for Membrane-Targeting Antimicrobial Approaches: Synergistic Biofilm Eradication and Antimicrobial Resistance Reversal.},
journal = {ACS applied materials & interfaces},
volume = {},
number = {},
pages = {},
doi = {10.1021/acsami.5c05491},
pmid = {40415377},
issn = {1944-8252},
abstract = {Membrane-targeting antimicrobials represent a promising class of materials to combat the escalating issue of antimicrobial resistance. Herein, we report a series of membrane-targeting conjugated oligoelectrolytes (COE-nT) featuring thienoacene moieties as π-conjugated cores, designed for tackling antimicrobial resistance. COE-nT exhibited higher activity against Gram-positive bacteria compared to Gram-negative bacteria, with no intrinsic resistance observed in either drug-resistant strain. Notably, a reduction in the π-conjugated length of COE-nT correlated with an increase in membrane permeability and toxicity toward cells and animals. Moreover, COE-nT demonstrated synergistic effects with commercial antibiotics against drug-resistant strains and restored susceptibility to ribosome-targeting antibiotics, such as clindamycin and erythromycin. To illustrate their synergistic potential, the combination of COE-4T and mupirocin was employed to treat methicillin-resistant Staphylococcus aureus infections in a murine wound model, resulting in significant biofilm eradication and enhanced antimicrobial efficacy. This new series of thienoacene-based COEs expands the antimicrobial COEs library with defined structure-activity relationship profiles and demonstrates its potential as a powerful adjunctive therapy for overcoming antimicrobial resistance.},
}
RevDate: 2025-05-27
CmpDate: 2025-05-25
Antibacterial efficacy of ultrasonically activated probiotic endodontic irrigant against Enterococcus faecalis biofilm: an in-vitro study.
BMC oral health, 25(1):794.
BACKGROUND: Enterococcus faecalis (E. faecalis) is the most frequently retrieved microorganism from teeth with failed endodontic treatment. Sodium hypochlorite (NaOCl) irrigant still poses some drawbacks, such as its cytotoxic effect and reduced effectiveness when applied at lower concentrations. Root canal disinfection by probiotics may yield positive outcomes due to their proven antibacterial and anti-inflammatory abilities. This research was intended to assess the antibacterial efficacy of a probiotic irrigant after ultrasonic activation against E. faecalis in a tooth model.
METHODS: Teeth specimens were infected with E. faecalis biofilm and then randomly divided into five groups according to the final flush irrigation protocol used; PRO for probiotic irrigant, PRO + for activated probiotic irrigant, NaOCl for NaOCl irrigant, NaOCl + for activated NaOCl irrigant, and saline for saline irrigation. Activation of the irrigant was done for 1 min using an Ultra X ultrasonic tip. By counting the colony-forming units per milliliter, the antibacterial activity was quantitatively evaluated for each group pre- and post-irrigation application; then, the bacterial load reduction percentages were calculated accordingly. The one-way ANOVA was conducted to compare the mean values of all variables, followed by the post-hoc Tukey test to make group comparisons with a significance level set at p < 0.05.
RESULTS: All experimental groups exerted antibacterial activity against E. faecalis with a reduction in the mean CFUs/mL values and an increase in the mean bacterial load reduction percentages. The lowest mean post-irrigation CFUs/mL values were observed in the NaOCl + group, followed by NaOCl, PRO + , PRO, and saline groups respectively. Statistically significant differences were observed among all groups, except for the NaOCl and PRO + groups which did not exhibit any statistically significant difference.
CONCLUSION: Ultrasonically activated probiotic irrigant revealed an antibacterial effect similar to the conventional NaOCl and can be effectively used to fight against E. faecalis biofilm.
Additional Links: PMID-40414833
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40414833,
year = {2025},
author = {Hanafy, MS and Kamal, NM and Fathallah, HA},
title = {Antibacterial efficacy of ultrasonically activated probiotic endodontic irrigant against Enterococcus faecalis biofilm: an in-vitro study.},
journal = {BMC oral health},
volume = {25},
number = {1},
pages = {794},
pmid = {40414833},
issn = {1472-6831},
mesh = {*Enterococcus faecalis/drug effects ; *Biofilms/drug effects ; *Root Canal Irrigants/pharmacology ; *Probiotics/pharmacology ; Sodium Hypochlorite/pharmacology ; Humans ; *Anti-Bacterial Agents/pharmacology ; Bacterial Load/drug effects ; In Vitro Techniques ; Dental Pulp Cavity/microbiology ; Ultrasonics ; },
abstract = {BACKGROUND: Enterococcus faecalis (E. faecalis) is the most frequently retrieved microorganism from teeth with failed endodontic treatment. Sodium hypochlorite (NaOCl) irrigant still poses some drawbacks, such as its cytotoxic effect and reduced effectiveness when applied at lower concentrations. Root canal disinfection by probiotics may yield positive outcomes due to their proven antibacterial and anti-inflammatory abilities. This research was intended to assess the antibacterial efficacy of a probiotic irrigant after ultrasonic activation against E. faecalis in a tooth model.
METHODS: Teeth specimens were infected with E. faecalis biofilm and then randomly divided into five groups according to the final flush irrigation protocol used; PRO for probiotic irrigant, PRO + for activated probiotic irrigant, NaOCl for NaOCl irrigant, NaOCl + for activated NaOCl irrigant, and saline for saline irrigation. Activation of the irrigant was done for 1 min using an Ultra X ultrasonic tip. By counting the colony-forming units per milliliter, the antibacterial activity was quantitatively evaluated for each group pre- and post-irrigation application; then, the bacterial load reduction percentages were calculated accordingly. The one-way ANOVA was conducted to compare the mean values of all variables, followed by the post-hoc Tukey test to make group comparisons with a significance level set at p < 0.05.
RESULTS: All experimental groups exerted antibacterial activity against E. faecalis with a reduction in the mean CFUs/mL values and an increase in the mean bacterial load reduction percentages. The lowest mean post-irrigation CFUs/mL values were observed in the NaOCl + group, followed by NaOCl, PRO + , PRO, and saline groups respectively. Statistically significant differences were observed among all groups, except for the NaOCl and PRO + groups which did not exhibit any statistically significant difference.
CONCLUSION: Ultrasonically activated probiotic irrigant revealed an antibacterial effect similar to the conventional NaOCl and can be effectively used to fight against E. faecalis biofilm.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
*Enterococcus faecalis/drug effects
*Biofilms/drug effects
*Root Canal Irrigants/pharmacology
*Probiotics/pharmacology
Sodium Hypochlorite/pharmacology
Humans
*Anti-Bacterial Agents/pharmacology
Bacterial Load/drug effects
In Vitro Techniques
Dental Pulp Cavity/microbiology
Ultrasonics
RevDate: 2025-05-25
Bacterial biofilm degradation by recombinant SpdAZ cloned from Streptococcus pyogenes ADUYE1.
Microbial pathogenesis pii:S0882-4010(25)00450-4 [Epub ahead of print].
Nucleases break down nucleic acids into smaller pieces or monomers. These enzymes are important in many biological activities, such as obtaining nucleotides necessary for cell division, DNA repair and recombination, fragmenting DNA during apoptosis, as well as functioning as an infectious agent or contributing to host defense mechanisms and disrupting bacterial biofilm structures. Herein, a nuclease from Streptococcus pyogenes (S. pyogenes) ADUYE1, homologous to the spd3 gene and named as spdAZ, was cloned and heterologously expressed in Escherichia coli (E. coli). Total protein was extracted from transformed E. coli and recombinant SpdAZ (rSpdAZ) was purified using IMAC method. Sequencing analysis of the cloned gene showed 5 amino acid substitutions between Spd3 and SpdAZ. The DNAse activity of the purified rSpdAZ was tested on viral, bacterial and eukaryotic DNA as well as with DNase agar. The anti-biofilm activity of rSpdAZ was tested against biofilms formed by 8 bacterial isolates, including Pseudomonas aeruginosa, E. coli, methicillin-resistant Staphylococcus aureus (MRSA), and methicillin-resistant Staphylococcus epidermidis (MRSE). Our results showed that rSpdAZ exhibited nuclease activity on all the DNA samples tested. rSpdAZ enzyme was effective against the biofilms formed by all the tested bacteria. While the effect of rSpdAZ in reducing the mature biofilm layers ranged between 65% and 93%, its effect in preventing biofilm formation (i.e., pre-biofilm) was between 48% and 91%. Enzyme activity against mature biofilms occurred after 4 hours in all studied species Biofilm formation is one of the main problems to fight against bacteria by decreasing efficacy of the antibacterial agents used. Our data suggest that rSpdAZ may be used as an antibiofilm agent.
Additional Links: PMID-40414440
Publisher:
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40414440,
year = {2025},
author = {Erdem Aynur, Z and Başbülbül, G and Karaynir, A and Bozdoğan, B},
title = {Bacterial biofilm degradation by recombinant SpdAZ cloned from Streptococcus pyogenes ADUYE1.},
journal = {Microbial pathogenesis},
volume = {},
number = {},
pages = {107725},
doi = {10.1016/j.micpath.2025.107725},
pmid = {40414440},
issn = {1096-1208},
abstract = {Nucleases break down nucleic acids into smaller pieces or monomers. These enzymes are important in many biological activities, such as obtaining nucleotides necessary for cell division, DNA repair and recombination, fragmenting DNA during apoptosis, as well as functioning as an infectious agent or contributing to host defense mechanisms and disrupting bacterial biofilm structures. Herein, a nuclease from Streptococcus pyogenes (S. pyogenes) ADUYE1, homologous to the spd3 gene and named as spdAZ, was cloned and heterologously expressed in Escherichia coli (E. coli). Total protein was extracted from transformed E. coli and recombinant SpdAZ (rSpdAZ) was purified using IMAC method. Sequencing analysis of the cloned gene showed 5 amino acid substitutions between Spd3 and SpdAZ. The DNAse activity of the purified rSpdAZ was tested on viral, bacterial and eukaryotic DNA as well as with DNase agar. The anti-biofilm activity of rSpdAZ was tested against biofilms formed by 8 bacterial isolates, including Pseudomonas aeruginosa, E. coli, methicillin-resistant Staphylococcus aureus (MRSA), and methicillin-resistant Staphylococcus epidermidis (MRSE). Our results showed that rSpdAZ exhibited nuclease activity on all the DNA samples tested. rSpdAZ enzyme was effective against the biofilms formed by all the tested bacteria. While the effect of rSpdAZ in reducing the mature biofilm layers ranged between 65% and 93%, its effect in preventing biofilm formation (i.e., pre-biofilm) was between 48% and 91%. Enzyme activity against mature biofilms occurred after 4 hours in all studied species Biofilm formation is one of the main problems to fight against bacteria by decreasing efficacy of the antibacterial agents used. Our data suggest that rSpdAZ may be used as an antibiofilm agent.},
}
RevDate: 2025-05-25
CmpDate: 2025-05-25
Relationship between antibiotic resistance and biofilm-forming capacity with RND efflux pumps expression in clinical Acinetobacter baumannii isolates.
Archives of microbiology, 207(7):153.
This study investigated the gene expression pattern of resistance-nodulation-division (RND) efflux pumps, in Acinetobacter baumannii isolates with a focus on their association with carbapenem resistance and biofilm formation ability. A collection of 102 A. baumannii isolates was evaluated for antibiotic susceptibility testing using an automated broth microdilution technique. The ability of these isolates to form biofilms was evaluated using a standardized protocol. The isolates were genotyped using the Multiple-Locus Variable number tandem repeat Analysis-8 (MLVA-8) method and the gene expression levels of the RND efflux pump genes were quantified by real-time PCR. Results showed widespread antibiotic resistance, with 85% of isolates classified as multidrug resistant. Genotyping results identified 32 different MLVA types organized into six clusters (A-F) and 17 unique genotypes. The majority of isolates demonstrated the ability to form biofilms, and an inverse relationship was observed between biofilm formation and carbapenem resistance. The expression of the adeB gene was significantly increased in carbapenem-non-susceptible A. baumannii isolates. In addition, the expression of the adeG gene was 2.08 times higher in isolates capable of forming moderate to strong biofilms compared to those forming weak biofilms. The novelty of this study is a new insight into the relationship between efflux pump expression, antibiotic resistance and biofilm formation in A. baumannii, as well as AdeABC overexpression in carbapenem-resistant isolates and AdeFGH overexpression in biofilm-forming strains, providing potential therapeutic targets. These findings suggest that targeting RND efflux pumps may be a promising strategy to control survival and antibiotic resistance of A. baumannii isolates through biofilm inhibition.
Additional Links: PMID-40413665
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40413665,
year = {2025},
author = {Farshadzadeh, Z and Khoshnood, S and Akrami, S and Abbasi Montazeri, E and Moradi, M and Masihzadeh, S and Daneshfar, S and Navidifar, T},
title = {Relationship between antibiotic resistance and biofilm-forming capacity with RND efflux pumps expression in clinical Acinetobacter baumannii isolates.},
journal = {Archives of microbiology},
volume = {207},
number = {7},
pages = {153},
pmid = {40413665},
issn = {1432-072X},
mesh = {*Acinetobacter baumannii/drug effects/genetics/physiology/isolation & purification ; *Biofilms/growth & development ; *Membrane Transport Proteins/genetics/metabolism ; *Anti-Bacterial Agents/pharmacology ; *Bacterial Proteins/genetics/metabolism ; Microbial Sensitivity Tests ; Carbapenems/pharmacology ; Humans ; Acinetobacter Infections/microbiology ; Drug Resistance, Multiple, Bacterial/genetics ; Genotype ; Gene Expression Regulation, Bacterial ; },
abstract = {This study investigated the gene expression pattern of resistance-nodulation-division (RND) efflux pumps, in Acinetobacter baumannii isolates with a focus on their association with carbapenem resistance and biofilm formation ability. A collection of 102 A. baumannii isolates was evaluated for antibiotic susceptibility testing using an automated broth microdilution technique. The ability of these isolates to form biofilms was evaluated using a standardized protocol. The isolates were genotyped using the Multiple-Locus Variable number tandem repeat Analysis-8 (MLVA-8) method and the gene expression levels of the RND efflux pump genes were quantified by real-time PCR. Results showed widespread antibiotic resistance, with 85% of isolates classified as multidrug resistant. Genotyping results identified 32 different MLVA types organized into six clusters (A-F) and 17 unique genotypes. The majority of isolates demonstrated the ability to form biofilms, and an inverse relationship was observed between biofilm formation and carbapenem resistance. The expression of the adeB gene was significantly increased in carbapenem-non-susceptible A. baumannii isolates. In addition, the expression of the adeG gene was 2.08 times higher in isolates capable of forming moderate to strong biofilms compared to those forming weak biofilms. The novelty of this study is a new insight into the relationship between efflux pump expression, antibiotic resistance and biofilm formation in A. baumannii, as well as AdeABC overexpression in carbapenem-resistant isolates and AdeFGH overexpression in biofilm-forming strains, providing potential therapeutic targets. These findings suggest that targeting RND efflux pumps may be a promising strategy to control survival and antibiotic resistance of A. baumannii isolates through biofilm inhibition.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
*Acinetobacter baumannii/drug effects/genetics/physiology/isolation & purification
*Biofilms/growth & development
*Membrane Transport Proteins/genetics/metabolism
*Anti-Bacterial Agents/pharmacology
*Bacterial Proteins/genetics/metabolism
Microbial Sensitivity Tests
Carbapenems/pharmacology
Humans
Acinetobacter Infections/microbiology
Drug Resistance, Multiple, Bacterial/genetics
Genotype
Gene Expression Regulation, Bacterial
RevDate: 2025-05-24
CmpDate: 2025-05-24
Naringenin as a Potent Natural Biofilm Inhibitor of Pseudomonas aeruginosa in Diabetic Foot Ulcers Through lasR Competitive Inhibition.
Current microbiology, 82(7):305.
Chronic non-healing foot ulcers are a major complication in diabetic patients, contributing to significant morbidity and mortality. Microorganisms in these wounds form biofilms, conferring greater virulence and enhanced protection from antibiotics. Hence, we examined naringenin, and other natural compounds like chlorofuranone, 4-nitropyridine N-oxide, and quercetin as a positive control against the major pathogenic organism that forms biofilm in foot ulcers. Here, we focused on Pseudomonas aeruginosa, which produces high levels of biofilm in diabetic foot ulcers. Naringenin (47.10 µg/ml for PA21; 124.7 µg/ml for PA333) and other natural compounds were tested for their ability to inhibit biofilm formation and virulence in vitro, and their effect on biofilm-associated gene expression was studied. The biofilm inhibitory mechanism of naringenin was elucidated using in silico analysis and in vitro reporter gene assay. In vitro biofilm assays, confocal and scanning electron microscopy showed that natural compounds effectively inhibited biofilm, without causing cell death. Treatment with these compounds significantly altered the expression of genes associated with quorum sensing in P. aeruginosa, such as lasR, pslA, algA, gacS, and pelA. Naringenin decreased the production of major virulence factors in P. aeruginosa. Molecular docking showed that naringenin exhibited the strongest binding affinity to LasR, and the same was validated by reporter gene assay using plasmid pSB1142 indicating its role as a competitive inhibitor in the las quorum sensing system in P. aeruginosa. The findings of this study could be extrapolated to in vivo diabetic wound infection models to help optimize the use of naringenin in effective biofilm control for better wound management in diabetic patients.
Additional Links: PMID-40413369
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40413369,
year = {2025},
author = {Warrier, A and Satyamoorthy, K and Murali, TS},
title = {Naringenin as a Potent Natural Biofilm Inhibitor of Pseudomonas aeruginosa in Diabetic Foot Ulcers Through lasR Competitive Inhibition.},
journal = {Current microbiology},
volume = {82},
number = {7},
pages = {305},
pmid = {40413369},
issn = {1432-0991},
support = {CRG/2022/003227//Science and Engineering Research Board/ ; MAC ID/SGA/2016/011//Manipal Centre for Infectious Diseases/ ; },
mesh = {*Biofilms/drug effects/growth & development ; *Pseudomonas aeruginosa/drug effects/physiology/genetics ; *Flavanones/pharmacology ; *Diabetic Foot/microbiology/drug therapy ; *Bacterial Proteins/antagonists & inhibitors/metabolism/genetics ; *Trans-Activators/antagonists & inhibitors/metabolism/genetics ; *Anti-Bacterial Agents/pharmacology ; Molecular Docking Simulation ; Quorum Sensing/drug effects ; Humans ; *Pseudomonas Infections/microbiology/drug therapy ; Gene Expression Regulation, Bacterial/drug effects ; Virulence Factors/genetics ; Virulence/drug effects ; },
abstract = {Chronic non-healing foot ulcers are a major complication in diabetic patients, contributing to significant morbidity and mortality. Microorganisms in these wounds form biofilms, conferring greater virulence and enhanced protection from antibiotics. Hence, we examined naringenin, and other natural compounds like chlorofuranone, 4-nitropyridine N-oxide, and quercetin as a positive control against the major pathogenic organism that forms biofilm in foot ulcers. Here, we focused on Pseudomonas aeruginosa, which produces high levels of biofilm in diabetic foot ulcers. Naringenin (47.10 µg/ml for PA21; 124.7 µg/ml for PA333) and other natural compounds were tested for their ability to inhibit biofilm formation and virulence in vitro, and their effect on biofilm-associated gene expression was studied. The biofilm inhibitory mechanism of naringenin was elucidated using in silico analysis and in vitro reporter gene assay. In vitro biofilm assays, confocal and scanning electron microscopy showed that natural compounds effectively inhibited biofilm, without causing cell death. Treatment with these compounds significantly altered the expression of genes associated with quorum sensing in P. aeruginosa, such as lasR, pslA, algA, gacS, and pelA. Naringenin decreased the production of major virulence factors in P. aeruginosa. Molecular docking showed that naringenin exhibited the strongest binding affinity to LasR, and the same was validated by reporter gene assay using plasmid pSB1142 indicating its role as a competitive inhibitor in the las quorum sensing system in P. aeruginosa. The findings of this study could be extrapolated to in vivo diabetic wound infection models to help optimize the use of naringenin in effective biofilm control for better wound management in diabetic patients.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
*Biofilms/drug effects/growth & development
*Pseudomonas aeruginosa/drug effects/physiology/genetics
*Flavanones/pharmacology
*Diabetic Foot/microbiology/drug therapy
*Bacterial Proteins/antagonists & inhibitors/metabolism/genetics
*Trans-Activators/antagonists & inhibitors/metabolism/genetics
*Anti-Bacterial Agents/pharmacology
Molecular Docking Simulation
Quorum Sensing/drug effects
Humans
*Pseudomonas Infections/microbiology/drug therapy
Gene Expression Regulation, Bacterial/drug effects
Virulence Factors/genetics
Virulence/drug effects
RevDate: 2025-05-24
CmpDate: 2025-05-24
Distribution of antibiotic resistance genes on chromosomes, plasmids and phages in aerobic biofilm microbiota under antibiotic pressure.
Journal of environmental sciences (China), 156:647-659.
The objective of this study is to quantitatively reveal the main genetic carrier of antibiotic resistance genes (ARGs) for blocking their environmental dissemination. The distribution of ARGs in chromosomes, plasmids, and phages for understanding their respective contributions to the development of antimicrobial resistance in aerobic biofilm consortium under increasing stresses of oxytetracycline, streptomycin, and tigecycline were revealed based on metagenomics analysis. Results showed that the plasmids harbored 49.2 %-83.9 % of resistomes, which was higher (p < 0.001) than chromosomes (2.0 %-35.6 %), and no ARGs were detected in phage contigs under the strict alignment standard of over 80 % identity used in this study. Plasmids and chromosomes tended to encode different types of ARGs, whose abundances all increased with the hike of antibiotic concentrations, and the variety of ARGs encoded by plasmids (14 types and 64 subtypes) was higher than that (11 types and 27 subtypes) of chromosomes. The dosing of the three antibiotics facilitated the transposition and recombination of ARGs on plasmids, mediated by transposable and integrable transfer elements, which increased the co-occurrence of associated and unassociated ARGs. The results quantitatively proved that plasmids dominate the proliferation of ARGs in aerobic biofilm driven by antibiotic selection, which should be a key target for blocking ARG dissemination.
Additional Links: PMID-40412963
Publisher:
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40412963,
year = {2025},
author = {Wang, C and Tian, Z and Luan, X and Zhang, H and Zhang, Y and Yang, M},
title = {Distribution of antibiotic resistance genes on chromosomes, plasmids and phages in aerobic biofilm microbiota under antibiotic pressure.},
journal = {Journal of environmental sciences (China)},
volume = {156},
number = {},
pages = {647-659},
doi = {10.1016/j.jes.2024.10.008},
pmid = {40412963},
issn = {1001-0742},
mesh = {*Biofilms/drug effects ; Plasmids/genetics ; *Anti-Bacterial Agents/pharmacology ; Bacteriophages/genetics ; *Drug Resistance, Microbial/genetics ; *Microbiota/genetics ; *Genes, Bacterial ; *Drug Resistance, Bacterial/genetics ; },
abstract = {The objective of this study is to quantitatively reveal the main genetic carrier of antibiotic resistance genes (ARGs) for blocking their environmental dissemination. The distribution of ARGs in chromosomes, plasmids, and phages for understanding their respective contributions to the development of antimicrobial resistance in aerobic biofilm consortium under increasing stresses of oxytetracycline, streptomycin, and tigecycline were revealed based on metagenomics analysis. Results showed that the plasmids harbored 49.2 %-83.9 % of resistomes, which was higher (p < 0.001) than chromosomes (2.0 %-35.6 %), and no ARGs were detected in phage contigs under the strict alignment standard of over 80 % identity used in this study. Plasmids and chromosomes tended to encode different types of ARGs, whose abundances all increased with the hike of antibiotic concentrations, and the variety of ARGs encoded by plasmids (14 types and 64 subtypes) was higher than that (11 types and 27 subtypes) of chromosomes. The dosing of the three antibiotics facilitated the transposition and recombination of ARGs on plasmids, mediated by transposable and integrable transfer elements, which increased the co-occurrence of associated and unassociated ARGs. The results quantitatively proved that plasmids dominate the proliferation of ARGs in aerobic biofilm driven by antibiotic selection, which should be a key target for blocking ARG dissemination.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
*Biofilms/drug effects
Plasmids/genetics
*Anti-Bacterial Agents/pharmacology
Bacteriophages/genetics
*Drug Resistance, Microbial/genetics
*Microbiota/genetics
*Genes, Bacterial
*Drug Resistance, Bacterial/genetics
RevDate: 2025-05-24
Delayed biofilm formation in non-motile uropathogenic Escherichia coli strain in static and dynamic growth conditions.
Microbial pathogenesis pii:S0882-4010(25)00437-1 [Epub ahead of print].
Urinary tract infections associated with the placement of indwelling urinary catheters are significant concern in hospital settings, as they are linked to an increased risk of severe infections and complications due to biofilm formation. These infections are primarily caused by uropathogens such as Escherichia coli (UPEC). UPEC possesses peritrichous flagella, which facilitates its motility, adhesion to surfaces, and biofilm formation. Understanding the development of UPEC communities is essential for developing effective treatment and eradication strategies. In this study, we characterized the biofilm formation of a clinical non-motile UPEC strain under both static and dynamic culture conditions that simulate the urinary catheter environment. We developed a dynamic culture system coupled with light sheet fluorescence microscopy (LSFM) to quantify the stages of biofilm formation over time. Our results demonstrate that flagella play a crucial role in the initial phase of biofilm formation. The non-motile strain exhibited a delay in the adhesion phase compared to motile strains but ultimately formed biofilms of similar volume during subsequent stages. These findings highlight the significance of flagella in dynamic biofilm formation models and provide valuable insights for modeling the evolution of bacterial communities in nosocomial environments using LSFM.
Additional Links: PMID-40412736
Publisher:
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40412736,
year = {2025},
author = {Canales-Huerta, N and Cádiz, M and Ulloa, MT and Chilet, LA and Palma, K and Jara-Wilde, J and Cuevas, F and González, MJ and Navarro, N and Toledo, J and Castañeda, V and Scavone, P and Härtel, S},
title = {Delayed biofilm formation in non-motile uropathogenic Escherichia coli strain in static and dynamic growth conditions.},
journal = {Microbial pathogenesis},
volume = {},
number = {},
pages = {107712},
doi = {10.1016/j.micpath.2025.107712},
pmid = {40412736},
issn = {1096-1208},
abstract = {Urinary tract infections associated with the placement of indwelling urinary catheters are significant concern in hospital settings, as they are linked to an increased risk of severe infections and complications due to biofilm formation. These infections are primarily caused by uropathogens such as Escherichia coli (UPEC). UPEC possesses peritrichous flagella, which facilitates its motility, adhesion to surfaces, and biofilm formation. Understanding the development of UPEC communities is essential for developing effective treatment and eradication strategies. In this study, we characterized the biofilm formation of a clinical non-motile UPEC strain under both static and dynamic culture conditions that simulate the urinary catheter environment. We developed a dynamic culture system coupled with light sheet fluorescence microscopy (LSFM) to quantify the stages of biofilm formation over time. Our results demonstrate that flagella play a crucial role in the initial phase of biofilm formation. The non-motile strain exhibited a delay in the adhesion phase compared to motile strains but ultimately formed biofilms of similar volume during subsequent stages. These findings highlight the significance of flagella in dynamic biofilm formation models and provide valuable insights for modeling the evolution of bacterial communities in nosocomial environments using LSFM.},
}
RevDate: 2025-05-23
Multidrug resistance, biofilm formation, and genetic determinants in diabetic foot infections from Uttar Pradesh, India: a clinical-microbiological insight from a prospective study.
Naunyn-Schmiedeberg's archives of pharmacology [Epub ahead of print].
This prospective cohort study systematically analyzed the demographic profile, clinical characteristics, spectrum of microorganisms, and antimicrobial resistance pattern in 248 patients with diabetic foot ulcer (DFU) over 2.7 years. Most patients were male (75.4%) and had a mean age of 56.1 years, and high comorbidity rates (81% neuropathy, 77% retinopathy, and 67.7% hypertension). A combined 439 bacterial isolates were obtained, with the dominance of Gram-negative pathogens, including Escherichia coli (16.6%) and Pseudomonas aeruginosa (15.3%). Staphylococcus aureus was also the dominant Gram-positive pathogen (12.8%). Polymicrobial infections were found in 43.1% of cases, and 71% of strains were biofilm-producing. The prevalence of multidrug-resistant (MDR) was alarmingly high (67%), particularly among Escherichia coli (97.3%), Staphylococcus aureus (83.9%), and Proteus mirabilis (90.5%). MDR infections were associated with tobacco use, biofilm formation, polymicrobial infection, and clinical complications. In specific, seven bacterial types, Pseudomonas aeruginosa, Staphylococcus aureus, Providencia rettgeri, Enterococcus faecalis, Enterobacter cloacae, Pseudomonas flourescens, and Staphylococcus epidermidis, as described, were statistically associated with amputation. Beta-lactams (ampicillin, piperacillin) showed 100% resistance. Cephalosporins (ceftazidime, ceftriaxone, cefotaxime, cefepime) had resistance rates ranging from 25 to 96%. Amoxicillin-clavulanic acid showed 30 to 92.3% resistance, while piperacillin-tazobactam ranged from 7.7 to 71.4% resistance. Out of 338 Gram-negative isolates, 105 (31.1%) were ESBL producers, and molecular characterization shows blaCTX-M as the most predominant, 40 (38.1%), followed by blaSHV 20 (19.0%), and blaTEM 7 (6.7%) isolates. Methicillin and vancomycin resistance were common among Gram-positive isolates, particularly Methicillin-resistant Staphylococcus aureus (MRSA) (51.8%) and Vancomycin-resistant Enterococci (VRE) (33.3%). Despite widespread resistance, antibacterial drugs such as colistin (100%), polymyxin B (100%), linezolid (100%), and vancomycin (100%) retained efficacy. These data emphasize the significant burden of MDR infections in DFUs and emphasize the urgent actions needed for aggressive antimicrobial stewardship, early infection control, and personalized treatment approaches to prevent amputation and enhance patient outcomes.
Additional Links: PMID-40410552
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40410552,
year = {2025},
author = {Saleem, M and Khan, MS and Neyaz, A and Ahmad, I and Qattan, MY and Ahmad, N},
title = {Multidrug resistance, biofilm formation, and genetic determinants in diabetic foot infections from Uttar Pradesh, India: a clinical-microbiological insight from a prospective study.},
journal = {Naunyn-Schmiedeberg's archives of pharmacology},
volume = {},
number = {},
pages = {},
pmid = {40410552},
issn = {1432-1912},
support = {Grant no. R.G.P.2/513/45//the Deanship of Research and Graduate Studies, King Khalid University, Abha, Saudi Arabia/ ; },
abstract = {This prospective cohort study systematically analyzed the demographic profile, clinical characteristics, spectrum of microorganisms, and antimicrobial resistance pattern in 248 patients with diabetic foot ulcer (DFU) over 2.7 years. Most patients were male (75.4%) and had a mean age of 56.1 years, and high comorbidity rates (81% neuropathy, 77% retinopathy, and 67.7% hypertension). A combined 439 bacterial isolates were obtained, with the dominance of Gram-negative pathogens, including Escherichia coli (16.6%) and Pseudomonas aeruginosa (15.3%). Staphylococcus aureus was also the dominant Gram-positive pathogen (12.8%). Polymicrobial infections were found in 43.1% of cases, and 71% of strains were biofilm-producing. The prevalence of multidrug-resistant (MDR) was alarmingly high (67%), particularly among Escherichia coli (97.3%), Staphylococcus aureus (83.9%), and Proteus mirabilis (90.5%). MDR infections were associated with tobacco use, biofilm formation, polymicrobial infection, and clinical complications. In specific, seven bacterial types, Pseudomonas aeruginosa, Staphylococcus aureus, Providencia rettgeri, Enterococcus faecalis, Enterobacter cloacae, Pseudomonas flourescens, and Staphylococcus epidermidis, as described, were statistically associated with amputation. Beta-lactams (ampicillin, piperacillin) showed 100% resistance. Cephalosporins (ceftazidime, ceftriaxone, cefotaxime, cefepime) had resistance rates ranging from 25 to 96%. Amoxicillin-clavulanic acid showed 30 to 92.3% resistance, while piperacillin-tazobactam ranged from 7.7 to 71.4% resistance. Out of 338 Gram-negative isolates, 105 (31.1%) were ESBL producers, and molecular characterization shows blaCTX-M as the most predominant, 40 (38.1%), followed by blaSHV 20 (19.0%), and blaTEM 7 (6.7%) isolates. Methicillin and vancomycin resistance were common among Gram-positive isolates, particularly Methicillin-resistant Staphylococcus aureus (MRSA) (51.8%) and Vancomycin-resistant Enterococci (VRE) (33.3%). Despite widespread resistance, antibacterial drugs such as colistin (100%), polymyxin B (100%), linezolid (100%), and vancomycin (100%) retained efficacy. These data emphasize the significant burden of MDR infections in DFUs and emphasize the urgent actions needed for aggressive antimicrobial stewardship, early infection control, and personalized treatment approaches to prevent amputation and enhance patient outcomes.},
}
RevDate: 2025-05-26
CmpDate: 2025-05-23
Titanium dioxide nanoparticles augment Ciprofloxacin activity via Inhibition of biofilm formation for multidrug resistance bacteria in-vitro and insilco prediction study.
Scientific reports, 15(1):18014.
The increasing of multi-drug among pathogenic microbes is rendering antibiotics ineffective. Consequently, efforts are now concentrated on addressing this challenge through developing novel antibiotics and enhancing existing ones. This study combined ciprofloxacin (CIP) with titanium dioxide nanoparticles (TiO2NPs). We characterized the prepared nanoparticles (NPs) using several methods, including UV-Vis spectra, XRD, FESEM, TEM, and FTIR. The well diffusion agar was used to study the antibacterial activity of ciprofloxacin (CIP) alone and combined with titanium dioxide nanoparticles CIP@TiO2NPs. CIP@TiO2NPs showed higher antibacterial activity against Klebsiella pneumoniae (K.pneumoniae) and Streptococcus mutans S.mutans. The CIP@TiO2NPs showed remarkable inhibitory properties compared to CIP alone and TiO2NP alone, with its inhibition zone 28.50 ± 0.20 and 17.50 ± 0.10 in K.pneumoniae and S.mutans, respectively. Insilico study was done on bacterial strains to describe the effective binding behavior towards the ciprofloxacin@TiO2 adsorption system. The best conformers, from 50 conformational adsorption systems, were analyzed with a significant favorable inhibition with binding energy values of -9.61 kcal/mol and - 9.40 kcal/mol with K.pneumoniae and S. mutans, respectively. The interaction between CIP@TiO2NPs nanoparticles and Klebsiella pneumonia (ID: 8JGW) was studied using 50 conformations. The results showed binding energies up to -9.61 kcal/mol, indicating high interaction efficacy. Compared to TiO2NPs and CIP alone, CIP@TiO2NPs displayed the highest antibacterial and anti-biofilm properties against pathogenic bacteria. CIP@TiO2NPs have demonstrated promising results, suggesting that they may prove to be a dependable treatment for K. pneumoniae and S.mutans in the future and a possible agent for reducing bacterial biofilm during bacterial infections.
Additional Links: PMID-40410449
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40410449,
year = {2025},
author = {Najm, MAA and Shakir, HA and Hasen, ST and Jawad, KH and Hasoon, BA and Jabir, MS and Issa, AA and Albukhaty, S and Gatasheh, MK and Molla, MH},
title = {Titanium dioxide nanoparticles augment Ciprofloxacin activity via Inhibition of biofilm formation for multidrug resistance bacteria in-vitro and insilco prediction study.},
journal = {Scientific reports},
volume = {15},
number = {1},
pages = {18014},
pmid = {40410449},
issn = {2045-2322},
mesh = {*Ciprofloxacin/pharmacology/chemistry ; *Titanium/chemistry/pharmacology ; *Biofilms/drug effects/growth & development ; Klebsiella pneumoniae/drug effects/physiology ; *Anti-Bacterial Agents/pharmacology/chemistry ; Streptococcus mutans/drug effects/physiology ; Microbial Sensitivity Tests ; *Metal Nanoparticles/chemistry ; *Drug Resistance, Multiple, Bacterial/drug effects ; *Nanoparticles/chemistry ; },
abstract = {The increasing of multi-drug among pathogenic microbes is rendering antibiotics ineffective. Consequently, efforts are now concentrated on addressing this challenge through developing novel antibiotics and enhancing existing ones. This study combined ciprofloxacin (CIP) with titanium dioxide nanoparticles (TiO2NPs). We characterized the prepared nanoparticles (NPs) using several methods, including UV-Vis spectra, XRD, FESEM, TEM, and FTIR. The well diffusion agar was used to study the antibacterial activity of ciprofloxacin (CIP) alone and combined with titanium dioxide nanoparticles CIP@TiO2NPs. CIP@TiO2NPs showed higher antibacterial activity against Klebsiella pneumoniae (K.pneumoniae) and Streptococcus mutans S.mutans. The CIP@TiO2NPs showed remarkable inhibitory properties compared to CIP alone and TiO2NP alone, with its inhibition zone 28.50 ± 0.20 and 17.50 ± 0.10 in K.pneumoniae and S.mutans, respectively. Insilico study was done on bacterial strains to describe the effective binding behavior towards the ciprofloxacin@TiO2 adsorption system. The best conformers, from 50 conformational adsorption systems, were analyzed with a significant favorable inhibition with binding energy values of -9.61 kcal/mol and - 9.40 kcal/mol with K.pneumoniae and S. mutans, respectively. The interaction between CIP@TiO2NPs nanoparticles and Klebsiella pneumonia (ID: 8JGW) was studied using 50 conformations. The results showed binding energies up to -9.61 kcal/mol, indicating high interaction efficacy. Compared to TiO2NPs and CIP alone, CIP@TiO2NPs displayed the highest antibacterial and anti-biofilm properties against pathogenic bacteria. CIP@TiO2NPs have demonstrated promising results, suggesting that they may prove to be a dependable treatment for K. pneumoniae and S.mutans in the future and a possible agent for reducing bacterial biofilm during bacterial infections.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
*Ciprofloxacin/pharmacology/chemistry
*Titanium/chemistry/pharmacology
*Biofilms/drug effects/growth & development
Klebsiella pneumoniae/drug effects/physiology
*Anti-Bacterial Agents/pharmacology/chemistry
Streptococcus mutans/drug effects/physiology
Microbial Sensitivity Tests
*Metal Nanoparticles/chemistry
*Drug Resistance, Multiple, Bacterial/drug effects
*Nanoparticles/chemistry
RevDate: 2025-05-25
Berberine@AgNPs@Carboxylated chitosan hydrogel dressing with immunomodulatory and anti-biofilm properties promotes wound repair in drug-resistant bacterial infections.
International journal of biological macromolecules, 315(Pt 1):144496 pii:S0141-8130(25)05048-2 [Epub ahead of print].
Methicillin-resistant Staphylococcus aureus (MRSA) is a bacterial strain resistant to multiple antibiotics frequently encountered in clinical settings. Excessive antibiotic use has increased bacterial resistance, leaving a lack of effective treatments for MRSA infections. MRSA often colonizes the surface of skin wounds, resulting in chronic inflammation and protracted wound healing. The biofilm formation hinders the complete eradication of the bacteria, exacerbating the local inflammatory response and impeding wound healing. This study presents an innovative methodology for managing MRSA-infected skin wounds. The novel immunomodulatory hydrogel composed of Berberine, silver nanoparticles (AgNPs), and carboxylated chitosan (designated as Ber@AgNPs@CHI hydrogel) demonstrates enhanced therapeutic efficacy in a murine model of MRSA skin infection. This hydrogel is effective in eradicating MRSA and preventing biofilm formation. Furthermore, it modulates the local immune microenvironment by facilitating the transition of macrophages from the M1 to M2 phenotype and increasing the production of vascular endothelial growth factor (VEGF). These actions collectively facilitate the progression of the wound from the inflammatory to the proliferative phase, enhancing the early stages of wound healing. Hence, this safe and effective hydrogel mediates wound healing from multiple perspectives and targets, providing a new potential avenue for treating persistent infected wounds caused by clinical MRSA.
Additional Links: PMID-40409636
Publisher:
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40409636,
year = {2025},
author = {Wang, X and Hu, J and Chen, C and Lu, J and Liu, C and Ning, Y and Lu, F},
title = {Berberine@AgNPs@Carboxylated chitosan hydrogel dressing with immunomodulatory and anti-biofilm properties promotes wound repair in drug-resistant bacterial infections.},
journal = {International journal of biological macromolecules},
volume = {315},
number = {Pt 1},
pages = {144496},
doi = {10.1016/j.ijbiomac.2025.144496},
pmid = {40409636},
issn = {1879-0003},
abstract = {Methicillin-resistant Staphylococcus aureus (MRSA) is a bacterial strain resistant to multiple antibiotics frequently encountered in clinical settings. Excessive antibiotic use has increased bacterial resistance, leaving a lack of effective treatments for MRSA infections. MRSA often colonizes the surface of skin wounds, resulting in chronic inflammation and protracted wound healing. The biofilm formation hinders the complete eradication of the bacteria, exacerbating the local inflammatory response and impeding wound healing. This study presents an innovative methodology for managing MRSA-infected skin wounds. The novel immunomodulatory hydrogel composed of Berberine, silver nanoparticles (AgNPs), and carboxylated chitosan (designated as Ber@AgNPs@CHI hydrogel) demonstrates enhanced therapeutic efficacy in a murine model of MRSA skin infection. This hydrogel is effective in eradicating MRSA and preventing biofilm formation. Furthermore, it modulates the local immune microenvironment by facilitating the transition of macrophages from the M1 to M2 phenotype and increasing the production of vascular endothelial growth factor (VEGF). These actions collectively facilitate the progression of the wound from the inflammatory to the proliferative phase, enhancing the early stages of wound healing. Hence, this safe and effective hydrogel mediates wound healing from multiple perspectives and targets, providing a new potential avenue for treating persistent infected wounds caused by clinical MRSA.},
}
RevDate: 2025-05-24
Quorum sensing mediated attenuation of biofilm formation and virulence traits in Staphylococcus aureus by trigonelline.
Microbial pathogenesis, 205:107731 pii:S0882-4010(25)00456-5 [Epub ahead of print].
Pathogenesis of Staphylococcus aureus is largely associated with its biofilm formation, that protects the cells from host immune system and antimicrobial threats. Considering the concern over the emergence of antimicrobial resistant S. aureus strains, this study was aimed to explore an effective alternative therapeutant. Trigonelline, an alkaloid, was evaluated for its antibiofilm and antivirulence activities against S. aureus. Trigonelline efficiently inhibited and eradicated biofilm, and abled to decrease the production of protease and hemolysin, the major virulence factors of S. aureus. Inhibition of biofilm formation and eradication of mature biofilm on the catheter surface suggested its potentiality in clinical application. The observed reduction in biofilm formation and virulence factor production following trigonelline treatment may be attributed to its ability to alter the expression of key regulatory genes such as agrA, sarA, saeR, arlR, icaR, and sigB, which control quorum sensing network and biofilm development. Additionally, molecular docking analysis revealed a substantial binding affinity of trigonelline to these regulatory proteins, further supporting its possible inhibitory mechanism. Thus, trigonelline might be a promising alternative chemical lead to manage biofilm-associated bacterial infections caused by S. aureus.
Additional Links: PMID-40409430
Publisher:
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40409430,
year = {2025},
author = {Kar, A and Mukherjee, SK and Hossain, ST},
title = {Quorum sensing mediated attenuation of biofilm formation and virulence traits in Staphylococcus aureus by trigonelline.},
journal = {Microbial pathogenesis},
volume = {205},
number = {},
pages = {107731},
doi = {10.1016/j.micpath.2025.107731},
pmid = {40409430},
issn = {1096-1208},
abstract = {Pathogenesis of Staphylococcus aureus is largely associated with its biofilm formation, that protects the cells from host immune system and antimicrobial threats. Considering the concern over the emergence of antimicrobial resistant S. aureus strains, this study was aimed to explore an effective alternative therapeutant. Trigonelline, an alkaloid, was evaluated for its antibiofilm and antivirulence activities against S. aureus. Trigonelline efficiently inhibited and eradicated biofilm, and abled to decrease the production of protease and hemolysin, the major virulence factors of S. aureus. Inhibition of biofilm formation and eradication of mature biofilm on the catheter surface suggested its potentiality in clinical application. The observed reduction in biofilm formation and virulence factor production following trigonelline treatment may be attributed to its ability to alter the expression of key regulatory genes such as agrA, sarA, saeR, arlR, icaR, and sigB, which control quorum sensing network and biofilm development. Additionally, molecular docking analysis revealed a substantial binding affinity of trigonelline to these regulatory proteins, further supporting its possible inhibitory mechanism. Thus, trigonelline might be a promising alternative chemical lead to manage biofilm-associated bacterial infections caused by S. aureus.},
}
RevDate: 2025-05-23
Immunometabolism shapes chronic Staphylococcus aureus infection: insights from biofilm infection models.
Current opinion in microbiology, 86:102612 pii:S1369-5274(25)00034-7 [Epub ahead of print].
Staphylococcus aureus is both a commensal bacterium and versatile pathogen, capable of transitioning from a benign colonizer to cause invasive disease. Its ability to form biofilm - a resilient, highly structured bacterial community - plays a key role in chronic infections, including those associated with medical implants and native tissues. The unique microenvironments of these biofilm niches create challenges for the host immune system, complicating pathogen clearance. Immunometabolism, the interplay between immune function and metabolic programming, plays a crucial role in dictating how the host combats S. aureus biofilms. Leukocytes undergo profound metabolic changes in response to biofilm, which can lead to dysregulated immune responses and persistent infection. This review explores recent insights defining the metabolic landscape of immune responses to S. aureus biofilm with a focus on two clinically relevant models, namely, craniotomy and prosthetic joint infection.
Additional Links: PMID-40409167
Publisher:
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40409167,
year = {2025},
author = {Ogunware, AE and Kielian, T},
title = {Immunometabolism shapes chronic Staphylococcus aureus infection: insights from biofilm infection models.},
journal = {Current opinion in microbiology},
volume = {86},
number = {},
pages = {102612},
doi = {10.1016/j.mib.2025.102612},
pmid = {40409167},
issn = {1879-0364},
abstract = {Staphylococcus aureus is both a commensal bacterium and versatile pathogen, capable of transitioning from a benign colonizer to cause invasive disease. Its ability to form biofilm - a resilient, highly structured bacterial community - plays a key role in chronic infections, including those associated with medical implants and native tissues. The unique microenvironments of these biofilm niches create challenges for the host immune system, complicating pathogen clearance. Immunometabolism, the interplay between immune function and metabolic programming, plays a crucial role in dictating how the host combats S. aureus biofilms. Leukocytes undergo profound metabolic changes in response to biofilm, which can lead to dysregulated immune responses and persistent infection. This review explores recent insights defining the metabolic landscape of immune responses to S. aureus biofilm with a focus on two clinically relevant models, namely, craniotomy and prosthetic joint infection.},
}
RevDate: 2025-05-23
Functional Amyloid Phenol-Soluble Modulin α1-Targeting Photothermal Nanoplatform for Effective Elimination of Biofilm-Associated Infections.
ACS nano [Epub ahead of print].
Biofilm-associated infections (BAIs) often lead to chronic infections and implant failure and are challenging to treat due to their resilience and complex structure, especially the extracellular polymeric substance (EPS). Phenol-soluble modulin α1 (PSMα1), a key biofilm-forming protein in methicillin-resistant Staphylococcus aureus (MRSA), can assemble into amyloid fibrils through self/cross-fibrillation and thus function as a scaffold that contributes to the integrity of the biofilm matrix. Here, using a phage display library-based biopanning strategy, we identified KG7, a PSMα1-targeting peptide that binds specifically to the fibrillation-dependent sequence in PSMα1, significantly inhibiting the amyloid fibrillation of PSMα1 and the subsequent biofilm formation in vitro. Further, the KG7 peptide was conjugated to the surface of polydopamine (PDA)-modified hollow copper sulfide (CuS) nanoparticles to develop an EPS-targeting photothermal nanoplatform (CuS@PPDA). This nanoplatform achieved a 94.7% biofilm inhibition rate and cleared 56.8% of mature biofilms through the regulation of PSMα1 fibrillation and the destruction of extracellular DNA, thanks to the synergistic effect of KG7-mediated inhibition and photothermal capability. Additionally, Cu[2+] release from the nanoplatform regulated macrophage polarization toward the M2 phenotype. In vivo studies also demonstrated that this nanoplatform significantly accelerated diabetic wound healing and prevented biofilm formation on implants, along with excellent antibacterial performance and tissue regeneration efficiency. This work introduces a proof-of-concept of photothermal nanoplatform targeting biofilm-scaffolding amyloid PSMα1, offering a promising treatment for BAIs.
Additional Links: PMID-40407368
Publisher:
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40407368,
year = {2025},
author = {Chen, C and Gao, Y and Qiao, X and Feng, Y and Yu, X and Cai, J and Hu, Q and Lin, X and Xuan, Q and Li, H},
title = {Functional Amyloid Phenol-Soluble Modulin α1-Targeting Photothermal Nanoplatform for Effective Elimination of Biofilm-Associated Infections.},
journal = {ACS nano},
volume = {},
number = {},
pages = {},
doi = {10.1021/acsnano.5c01761},
pmid = {40407368},
issn = {1936-086X},
abstract = {Biofilm-associated infections (BAIs) often lead to chronic infections and implant failure and are challenging to treat due to their resilience and complex structure, especially the extracellular polymeric substance (EPS). Phenol-soluble modulin α1 (PSMα1), a key biofilm-forming protein in methicillin-resistant Staphylococcus aureus (MRSA), can assemble into amyloid fibrils through self/cross-fibrillation and thus function as a scaffold that contributes to the integrity of the biofilm matrix. Here, using a phage display library-based biopanning strategy, we identified KG7, a PSMα1-targeting peptide that binds specifically to the fibrillation-dependent sequence in PSMα1, significantly inhibiting the amyloid fibrillation of PSMα1 and the subsequent biofilm formation in vitro. Further, the KG7 peptide was conjugated to the surface of polydopamine (PDA)-modified hollow copper sulfide (CuS) nanoparticles to develop an EPS-targeting photothermal nanoplatform (CuS@PPDA). This nanoplatform achieved a 94.7% biofilm inhibition rate and cleared 56.8% of mature biofilms through the regulation of PSMα1 fibrillation and the destruction of extracellular DNA, thanks to the synergistic effect of KG7-mediated inhibition and photothermal capability. Additionally, Cu[2+] release from the nanoplatform regulated macrophage polarization toward the M2 phenotype. In vivo studies also demonstrated that this nanoplatform significantly accelerated diabetic wound healing and prevented biofilm formation on implants, along with excellent antibacterial performance and tissue regeneration efficiency. This work introduces a proof-of-concept of photothermal nanoplatform targeting biofilm-scaffolding amyloid PSMα1, offering a promising treatment for BAIs.},
}
RevDate: 2025-05-23
A dynamic microcosm biofilm model for root carious-like lesion development: analysis of demineralization and microbiological characterization.
Biofouling [Epub ahead of print].
This study investigated the multifunctional oral cavity simulator (MOCS) in terms of microbial composition, functional profile, and dentin root demineralization. Microcosm biofilms were grown on dentin using human saliva for 4, 7, and 14 days, with exposure to sucrose and a mucin-enriched medium. Biofilms were analyzed for microbial viability and composition through CFU count and 16S-rRNA gene sequencing. Demineralization was quantified by percentage surface hardness change (%SHC), mineral loss (ML), and lesion depth (LD). The results showed microbial viability at all time points. After 7 days, aciduric/acidogenic and proteolytic organisms increased in abundance. The functional profile reflected the oscillations in microbial composition. No significant differences in %SHC, ML, or LD were observed across the time points. Carious lesions exhibited 60-70% SHC and 125-200 µm depth. MOCS was able to induce root carious lesions as result of microcosm biofilm metabolic activity, indicating its potential use in preclinical studies on root dentin caries.
Additional Links: PMID-40405518
Publisher:
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40405518,
year = {2025},
author = {Maske, TT and Marques, GÁ and Fritsch, BD and Kremer, BM and Cenci, MS and Rampelotto, PH and Arthur, RA},
title = {A dynamic microcosm biofilm model for root carious-like lesion development: analysis of demineralization and microbiological characterization.},
journal = {Biofouling},
volume = {},
number = {},
pages = {1-15},
doi = {10.1080/08927014.2025.2507893},
pmid = {40405518},
issn = {1029-2454},
abstract = {This study investigated the multifunctional oral cavity simulator (MOCS) in terms of microbial composition, functional profile, and dentin root demineralization. Microcosm biofilms were grown on dentin using human saliva for 4, 7, and 14 days, with exposure to sucrose and a mucin-enriched medium. Biofilms were analyzed for microbial viability and composition through CFU count and 16S-rRNA gene sequencing. Demineralization was quantified by percentage surface hardness change (%SHC), mineral loss (ML), and lesion depth (LD). The results showed microbial viability at all time points. After 7 days, aciduric/acidogenic and proteolytic organisms increased in abundance. The functional profile reflected the oscillations in microbial composition. No significant differences in %SHC, ML, or LD were observed across the time points. Carious lesions exhibited 60-70% SHC and 125-200 µm depth. MOCS was able to induce root carious lesions as result of microcosm biofilm metabolic activity, indicating its potential use in preclinical studies on root dentin caries.},
}
RevDate: 2025-05-25
CmpDate: 2025-05-22
Pathogenicity of commensal gut biofilm in prefrail aging.
NPJ biofilms and microbiomes, 11(1):84.
Pathophysiological mechanisms of unhealthy aging, particularly the transition from robustness to frailty, remain poorly understood. Despite extensive microbiome research on taxonomy, the behavior of early prefrail gut bacteria in their natural community-host mucosal tissue context remains unexplored. Using fecal samples from the INSPIRE-T aging human cohort, we characterized gut microbiota phenotype during prefrailty stages using a polymicrobial biofilm model. Results revealed that prefrail-derived biofilms exhibited distinct taxonomic and physical alterations, enhanced dispersal, and increased epithelial virulence compared to robust counterparts. Multiparametric analyses linked biofilm characteristics to clinical traits, suggesting their potential as aging status indicators. Polyphenol-rich grape pomace extract partially reversed prefrail biofilm alterations and reduced proinflammatory prefrail biofilm responses in vitro. Microbiota from prefrail-aged mice induced colon damage in antibiotic-treated recipients, establishing a prefrail microbiome-inflammation causality. Overall, the findings identified novel prefrail microbiome characteristics, established causal inflammatory links, and supported microbiota-targeted geroprotective interventions for the prefrail populations.
Additional Links: PMID-40404666
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40404666,
year = {2025},
author = {Le Cosquer, G and Pannier, M and Meunier, E and Thevenin, J and Pyhourquet, E and Guyonnet, S and Vellas, B and Santin, Y and Guiard, B and Parini, A and Buscail, L and Bournet, B and Guillemet, D and Deraison, C and Vergnolle, N and Motta, JP and , },
title = {Pathogenicity of commensal gut biofilm in prefrail aging.},
journal = {NPJ biofilms and microbiomes},
volume = {11},
number = {1},
pages = {84},
pmid = {40404666},
issn = {2055-5008},
support = {IHU HealthAge Open Science initiative//ANR-23-IAHU-0011/ ; IHU HealthAge Open Science initiative//ANR-23-IAHU-0011/ ; PARCURE PRCE-CE18, 2020//ANR/ ; dysBIOFILM ANR-22-CE14-0041-01//ANR/ ; national program "Microbiote"//INSERM/ ; national program "Microbiote"//INSERM/ ; AMIGO//INSPIRE-Grant/ ; },
mesh = {*Biofilms/growth & development/drug effects ; *Gastrointestinal Microbiome/drug effects ; Animals ; Humans ; Mice ; *Aging ; Feces/microbiology ; *Bacteria/pathogenicity/classification/genetics/drug effects/isolation & purification ; Female ; Male ; Virulence ; Frailty/microbiology ; Aged ; Plant Extracts/pharmacology ; Vitis/chemistry ; },
abstract = {Pathophysiological mechanisms of unhealthy aging, particularly the transition from robustness to frailty, remain poorly understood. Despite extensive microbiome research on taxonomy, the behavior of early prefrail gut bacteria in their natural community-host mucosal tissue context remains unexplored. Using fecal samples from the INSPIRE-T aging human cohort, we characterized gut microbiota phenotype during prefrailty stages using a polymicrobial biofilm model. Results revealed that prefrail-derived biofilms exhibited distinct taxonomic and physical alterations, enhanced dispersal, and increased epithelial virulence compared to robust counterparts. Multiparametric analyses linked biofilm characteristics to clinical traits, suggesting their potential as aging status indicators. Polyphenol-rich grape pomace extract partially reversed prefrail biofilm alterations and reduced proinflammatory prefrail biofilm responses in vitro. Microbiota from prefrail-aged mice induced colon damage in antibiotic-treated recipients, establishing a prefrail microbiome-inflammation causality. Overall, the findings identified novel prefrail microbiome characteristics, established causal inflammatory links, and supported microbiota-targeted geroprotective interventions for the prefrail populations.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
*Biofilms/growth & development/drug effects
*Gastrointestinal Microbiome/drug effects
Animals
Humans
Mice
*Aging
Feces/microbiology
*Bacteria/pathogenicity/classification/genetics/drug effects/isolation & purification
Female
Male
Virulence
Frailty/microbiology
Aged
Plant Extracts/pharmacology
Vitis/chemistry
RevDate: 2025-05-22
Microbial conversion of methane into single cell protein in a dual-membrane biofilm reactor.
Water research, 283:123838 pii:S0043-1354(25)00746-8 [Epub ahead of print].
Single cell protein (SCP, or microbial protein) is a promising alternative food source that could sustainably address the growing demand for proteins. Recently, methane, as the main component of biogas, has been explored as a carbon and energy source for SCP production due to its lower cost and renewability compared to traditional substrates such as carbohydrates. However, a major challenge is how to safely deliver methane and oxygen, and the explosion risk impedes the CH4-based SCP production. This study designed a dual-membrane biofilm reactor (dMBfR) for SCP production from methane, incorporating hollow fiber membranes to enhance the delivery of methane and oxygen. Over a 240-day operation, methane utilization efficiency reached 100 %, achieving the SCP yield of up to 0.49 g SCP/g CH4. The reactor also exhibited competitive protein content of 50.2 % and biomass productivity of 506 mg/L/d. Additionally, we evaluated the reactor performance in response to varying aeration modes (open-end versus dead-end) and weekly protein harvest ratios (20 % versus 50 %). Compared to the dead-end aeration mode, the open-end mode led to 1.5-fold higher SCP production rates, 3.5-fold higher nitrogen-based SCP yields, 3.7-fold higher carbon-based SCP yields, and 1.1-fold higher protein content. Moreover, we applied the freeze-drying approach to produce dry SCP products in the reactor. The final SCP products exhibited higher solubility (17.4 %), water holding capacity (5.0 %), and emulsifying stability (93.3 %, after 24 h incubation) compared to typical fish meals, jointly indicative of the high quality of the produced SCP. This work offers valuable insights into CH4-based SCP production, offering a promising avenue for efficient microbial protein synthesis.
Additional Links: PMID-40403554
Publisher:
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40403554,
year = {2025},
author = {Ma, Y and Liu, T and Yuan, Z and Guo, J},
title = {Microbial conversion of methane into single cell protein in a dual-membrane biofilm reactor.},
journal = {Water research},
volume = {283},
number = {},
pages = {123838},
doi = {10.1016/j.watres.2025.123838},
pmid = {40403554},
issn = {1879-2448},
abstract = {Single cell protein (SCP, or microbial protein) is a promising alternative food source that could sustainably address the growing demand for proteins. Recently, methane, as the main component of biogas, has been explored as a carbon and energy source for SCP production due to its lower cost and renewability compared to traditional substrates such as carbohydrates. However, a major challenge is how to safely deliver methane and oxygen, and the explosion risk impedes the CH4-based SCP production. This study designed a dual-membrane biofilm reactor (dMBfR) for SCP production from methane, incorporating hollow fiber membranes to enhance the delivery of methane and oxygen. Over a 240-day operation, methane utilization efficiency reached 100 %, achieving the SCP yield of up to 0.49 g SCP/g CH4. The reactor also exhibited competitive protein content of 50.2 % and biomass productivity of 506 mg/L/d. Additionally, we evaluated the reactor performance in response to varying aeration modes (open-end versus dead-end) and weekly protein harvest ratios (20 % versus 50 %). Compared to the dead-end aeration mode, the open-end mode led to 1.5-fold higher SCP production rates, 3.5-fold higher nitrogen-based SCP yields, 3.7-fold higher carbon-based SCP yields, and 1.1-fold higher protein content. Moreover, we applied the freeze-drying approach to produce dry SCP products in the reactor. The final SCP products exhibited higher solubility (17.4 %), water holding capacity (5.0 %), and emulsifying stability (93.3 %, after 24 h incubation) compared to typical fish meals, jointly indicative of the high quality of the produced SCP. This work offers valuable insights into CH4-based SCP production, offering a promising avenue for efficient microbial protein synthesis.},
}
RevDate: 2025-05-22
Multiple genome analysis of Staphylococcus aureus from wild ungulates renders new insights into the links between genetic diversity and biofilm formation.
Journal of applied microbiology pii:8140857 [Epub ahead of print].
AIMS: Staphylococcus aureus is an opportunistic pathogen affecting humans and animals, with infection imposing significant socio-ecological burden. Its ability to colonize new hosts is linked to adhesion and biofilm formation. While biofilm studies mainly focus on human and livestock isolates, those from wildlife remain understudied. This study investigates whether S. aureus adapted to wild artiodactyls undergoes genome remodeling for biofilm establishment.
METHODS AND RESULTS: We analyzed 110 S. aureus genomes from three wild ungulate species with distinct biofilm phenotypes, searching for genetic variants exclusive to strong or weak biofilm producers (SBP/WBP). We examined 15 biofilm-related genes and performed microbial genome-wide association studies (mGWAS). Isolates of sequence type (ST) ST6133, related to clonal complex CC398, formed significantly stronger biofilms than other STs. Across biofilm-related genes, 697 single nucleotide polymorphisms (SNPs) were identified, with a balanced ratio of synonymous and non-synonymous mutations. Two non-synonymous SNPs in clfA (n.2894C>T; p.Thr965Ile) and icaB (n.431G>A; p.Gly144Glu) were exclusive to WBP, while one in icaA (n.767C>T; p.Thr256Ile) was found only in SBP. However, no SNP was universally associated with either phenotype. Genes fnbA, ebpS, and clfA had the highest missense mutation rates, while fib showed the highest mutation ratio per sequence size. The mGWAS identified a genomic element linked to SBP -comprising a putative primase and four hypothetical proteins (two with prophage-related domains)- potentially influencing colonization efficiency.
CONCLUSIONS: Despite complexity of biofilm mechanisms, our findings reveal S. aureus genetic factors associated with biofilm formation and colonization of wildlife, highlighting variants for further study.
Additional Links: PMID-40402823
Publisher:
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40402823,
year = {2025},
author = {Teixeira, S and Ramos, B and Cunha, MV},
title = {Multiple genome analysis of Staphylococcus aureus from wild ungulates renders new insights into the links between genetic diversity and biofilm formation.},
journal = {Journal of applied microbiology},
volume = {},
number = {},
pages = {},
doi = {10.1093/jambio/lxaf126},
pmid = {40402823},
issn = {1365-2672},
abstract = {AIMS: Staphylococcus aureus is an opportunistic pathogen affecting humans and animals, with infection imposing significant socio-ecological burden. Its ability to colonize new hosts is linked to adhesion and biofilm formation. While biofilm studies mainly focus on human and livestock isolates, those from wildlife remain understudied. This study investigates whether S. aureus adapted to wild artiodactyls undergoes genome remodeling for biofilm establishment.
METHODS AND RESULTS: We analyzed 110 S. aureus genomes from three wild ungulate species with distinct biofilm phenotypes, searching for genetic variants exclusive to strong or weak biofilm producers (SBP/WBP). We examined 15 biofilm-related genes and performed microbial genome-wide association studies (mGWAS). Isolates of sequence type (ST) ST6133, related to clonal complex CC398, formed significantly stronger biofilms than other STs. Across biofilm-related genes, 697 single nucleotide polymorphisms (SNPs) were identified, with a balanced ratio of synonymous and non-synonymous mutations. Two non-synonymous SNPs in clfA (n.2894C>T; p.Thr965Ile) and icaB (n.431G>A; p.Gly144Glu) were exclusive to WBP, while one in icaA (n.767C>T; p.Thr256Ile) was found only in SBP. However, no SNP was universally associated with either phenotype. Genes fnbA, ebpS, and clfA had the highest missense mutation rates, while fib showed the highest mutation ratio per sequence size. The mGWAS identified a genomic element linked to SBP -comprising a putative primase and four hypothetical proteins (two with prophage-related domains)- potentially influencing colonization efficiency.
CONCLUSIONS: Despite complexity of biofilm mechanisms, our findings reveal S. aureus genetic factors associated with biofilm formation and colonization of wildlife, highlighting variants for further study.},
}
RevDate: 2025-05-23
The potential impact of iron supply on the development of starved Enterococcus faecalis biofilm by modulating the liberation of extracellular DNA.
Frontiers in microbiology, 16:1526909.
Enterococcus faecalis (E. faecalis) is commonly associated with persistent periapical infections. Even after multiple courses of root canal therapy, the infection is difficult to eradicate due to its drug resistance and adaptability. However, root canal treatment will remove nutrients from the root canal and make the remaining E. faecalis near starvation. Iron is an essential element for the growth and metabolism of E. faecalis, but previous studies were mostly based on bacterial nutrient sufficient conditions. Therefore, in this study, the starvation state was used as the breakthrough point to explore the mechanism of iron on the biofilm formation of E. faecalis, so as to be more suitable for clinical practice. In this study, we first constructed a starving E. faecalis model. Subsequently, we found that iron supply promoted biofilm formation in starved E. faecalis, with more eDNA in the biofilm. Iron starvation induced by the iron competitive inhibitor gallium nitrate reduced biofilm formation but increased the proportion of eDNA. In contrast, high iron levels in the environment counteracted this inhibition of biofilm formation. Following DNase I treatment, both the eDNA content and viable bacteria within the biofilm of the iron-supply group exhibited a statistically significant reduction. These results suggest that iron supply may regulate the proliferation of active bacteria by regulating eDNA release, thereby promoting biofilm formation of starved E. faecalis and providing a new perspective on its survival strategy under stress.
Additional Links: PMID-40400678
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40400678,
year = {2025},
author = {Zhen, Y and Baima, Q and Yang, S and Cao, Y and Meng, X},
title = {The potential impact of iron supply on the development of starved Enterococcus faecalis biofilm by modulating the liberation of extracellular DNA.},
journal = {Frontiers in microbiology},
volume = {16},
number = {},
pages = {1526909},
pmid = {40400678},
issn = {1664-302X},
abstract = {Enterococcus faecalis (E. faecalis) is commonly associated with persistent periapical infections. Even after multiple courses of root canal therapy, the infection is difficult to eradicate due to its drug resistance and adaptability. However, root canal treatment will remove nutrients from the root canal and make the remaining E. faecalis near starvation. Iron is an essential element for the growth and metabolism of E. faecalis, but previous studies were mostly based on bacterial nutrient sufficient conditions. Therefore, in this study, the starvation state was used as the breakthrough point to explore the mechanism of iron on the biofilm formation of E. faecalis, so as to be more suitable for clinical practice. In this study, we first constructed a starving E. faecalis model. Subsequently, we found that iron supply promoted biofilm formation in starved E. faecalis, with more eDNA in the biofilm. Iron starvation induced by the iron competitive inhibitor gallium nitrate reduced biofilm formation but increased the proportion of eDNA. In contrast, high iron levels in the environment counteracted this inhibition of biofilm formation. Following DNase I treatment, both the eDNA content and viable bacteria within the biofilm of the iron-supply group exhibited a statistically significant reduction. These results suggest that iron supply may regulate the proliferation of active bacteria by regulating eDNA release, thereby promoting biofilm formation of starved E. faecalis and providing a new perspective on its survival strategy under stress.},
}
RevDate: 2025-05-21
CmpDate: 2025-05-22
Biofilm formation capacity and Carbapenem-resistance in Acinetobacter-calcoaceticus-baumannii isolated from inpatients in a tertiary care hospital in Nepal.
BMC research notes, 18(1):225.
OBJECTIVE: Acinetobacter calcoaceticus-baumannii complex (ACBC), as an emerging global burden to various clinical infections, has a huge problem in empirical therapy due to the increasing resistance to the majority of antibiotics. The ability of biofilm formation added to its antimicrobial resistance and helped its persistence and survival in the environment. To associate biofilm formation with carbapenem resistance, a hospital-based cross-sectional study was carried out from February 2020 to August 2020 at Kathmandu Model Hospital, Kathmandu, Nepal. ACBC was identified from the clinical samples following standard Microbiological procedures. A modified Kirby-Bauer disk diffusion method was performed to assay the antibiotic susceptibility testing of ACBC isolates to various antibiotic classes. A quantitative adherence assay was used to determine the biofilm assay. A conventional Polymerase Chain Reaction (PCR) method was used to find the targeted biofilm-related genes, Bap, csuE, and blaPER1 using specific primers.
RESULTS: Out of 665 different clinical samples, bacterial growth was observed in 281 (42.3%) clinical samples. Of these, 32 (11.4%) isolates were identified as ACBC. Out of 32 ACBC isolates, 29 (90.6%) of which were carbapenem-resistant. All carbapenem-resistant ACBC isolates were found to be sensitive to Polymixin B and Colistin. Out of 29 CR-ACBC, 17.2% of isolates were resistant to Tigecycline. The majority of ACBC isolates (93.8%) were multidrug-resistant (MDR) while 13 (40.6%) of isolates were extensively drug-resistant (XDR). A total of 31 ACBC isolates were biofilm producers, out of which 2 were strong biofilm producers followed by 8 moderate, and 21 were weak biofilm producers. The occurrence of biofilm-forming genes; Bap, csuE, and blaPER1 genes were found to be 65.6%, 65.6%, and 56.3% respectively among ACBC clinical isolates. A significant association was observed between carbapenem resistance, biofilm formation, and biofilm-related genes.
CONCLUSION: The higher rate of MDR and XDR ACBC isolates associated with biofilm formation in the study alarms the ACBC-related infection in clinical settings among inpatients. The hospital environment and clinical equipment are potential sources of biofilm-forming isolates. Hence, the effective sterilization of clinical equipment and hospital environment are utmost and a strong policy should be made to prescribe the proper antibiotic based on antibiogram profile to fight against an emerging threat of ACBC infections.
Additional Links: PMID-40399960
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40399960,
year = {2025},
author = {Bhandari, S and Upreti, MK and Angbuhang, KB and Shrestha, B and Thapa Shrestha, U},
title = {Biofilm formation capacity and Carbapenem-resistance in Acinetobacter-calcoaceticus-baumannii isolated from inpatients in a tertiary care hospital in Nepal.},
journal = {BMC research notes},
volume = {18},
number = {1},
pages = {225},
pmid = {40399960},
issn = {1756-0500},
mesh = {*Biofilms/drug effects/growth & development ; Nepal ; Humans ; *Carbapenems/pharmacology ; Tertiary Care Centers ; Cross-Sectional Studies ; *Acinetobacter baumannii/drug effects/isolation & purification/physiology/genetics ; *Anti-Bacterial Agents/pharmacology ; *Acinetobacter Infections/microbiology/drug therapy ; *Acinetobacter calcoaceticus/drug effects/isolation & purification/physiology/genetics ; Microbial Sensitivity Tests ; Inpatients ; *Drug Resistance, Bacterial ; Drug Resistance, Multiple, Bacterial ; },
abstract = {OBJECTIVE: Acinetobacter calcoaceticus-baumannii complex (ACBC), as an emerging global burden to various clinical infections, has a huge problem in empirical therapy due to the increasing resistance to the majority of antibiotics. The ability of biofilm formation added to its antimicrobial resistance and helped its persistence and survival in the environment. To associate biofilm formation with carbapenem resistance, a hospital-based cross-sectional study was carried out from February 2020 to August 2020 at Kathmandu Model Hospital, Kathmandu, Nepal. ACBC was identified from the clinical samples following standard Microbiological procedures. A modified Kirby-Bauer disk diffusion method was performed to assay the antibiotic susceptibility testing of ACBC isolates to various antibiotic classes. A quantitative adherence assay was used to determine the biofilm assay. A conventional Polymerase Chain Reaction (PCR) method was used to find the targeted biofilm-related genes, Bap, csuE, and blaPER1 using specific primers.
RESULTS: Out of 665 different clinical samples, bacterial growth was observed in 281 (42.3%) clinical samples. Of these, 32 (11.4%) isolates were identified as ACBC. Out of 32 ACBC isolates, 29 (90.6%) of which were carbapenem-resistant. All carbapenem-resistant ACBC isolates were found to be sensitive to Polymixin B and Colistin. Out of 29 CR-ACBC, 17.2% of isolates were resistant to Tigecycline. The majority of ACBC isolates (93.8%) were multidrug-resistant (MDR) while 13 (40.6%) of isolates were extensively drug-resistant (XDR). A total of 31 ACBC isolates were biofilm producers, out of which 2 were strong biofilm producers followed by 8 moderate, and 21 were weak biofilm producers. The occurrence of biofilm-forming genes; Bap, csuE, and blaPER1 genes were found to be 65.6%, 65.6%, and 56.3% respectively among ACBC clinical isolates. A significant association was observed between carbapenem resistance, biofilm formation, and biofilm-related genes.
CONCLUSION: The higher rate of MDR and XDR ACBC isolates associated with biofilm formation in the study alarms the ACBC-related infection in clinical settings among inpatients. The hospital environment and clinical equipment are potential sources of biofilm-forming isolates. Hence, the effective sterilization of clinical equipment and hospital environment are utmost and a strong policy should be made to prescribe the proper antibiotic based on antibiogram profile to fight against an emerging threat of ACBC infections.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
*Biofilms/drug effects/growth & development
Nepal
Humans
*Carbapenems/pharmacology
Tertiary Care Centers
Cross-Sectional Studies
*Acinetobacter baumannii/drug effects/isolation & purification/physiology/genetics
*Anti-Bacterial Agents/pharmacology
*Acinetobacter Infections/microbiology/drug therapy
*Acinetobacter calcoaceticus/drug effects/isolation & purification/physiology/genetics
Microbial Sensitivity Tests
Inpatients
*Drug Resistance, Bacterial
Drug Resistance, Multiple, Bacterial
RevDate: 2025-05-21
CmpDate: 2025-05-22
Biofilm formation by the host microbiota: a protective shield against immunity and its implication in cancer.
Molecular cancer, 24(1):148.
Human-resident microbes typically cluster into biofilms - structurally organized communities embedded within a matrix of self-produced extracellular polymeric substance (EPS) that serves as a protective shield. These biofilms enhance microbial survival and functional adaptability, favoring a symbiotic relationship with the host under physiological conditions. However, biofilms exhibit a dual role in modulating the immune response. If their ability to promote tolerance is key to safeguarding homeostasis, by contrast, their persistence can overcome the cutting-edge balance resulting in immune evasion, chronic inflammation and development of numerous diseases such as cancer. Recent evidence highlights the significance of cancer-associated microbiota in shaping the tumor microenvironment (TME). These microbial inhabitants often exhibit biofilm-like structures, which may protect them from host immune responses and therapeutic interventions. The presence of biofilm-forming microbiota within the TME may promote chronic inflammation, and release of bioactive molecules that interfere with immune surveillance mechanisms, thereby enabling cancer cells to evade immune destruction. This review delves into the complex interplay between biofilms and cancer, with particular focus on the tumor-associated microbiota and the implications of biofilm involvement in modulating the immune landscape of the TME. Addressing this intricate relationship holds promises for innovative therapeutic approaches aimed at reprogramming the microbiota-cancer axis for better clinical outcomes.
Additional Links: PMID-40399923
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40399923,
year = {2025},
author = {Montanari, E and Bernardo, G and Le Noci, V and Anselmi, M and Pupa, SM and Tagliabue, E and Sommariva, M and Sfondrini, L},
title = {Biofilm formation by the host microbiota: a protective shield against immunity and its implication in cancer.},
journal = {Molecular cancer},
volume = {24},
number = {1},
pages = {148},
pmid = {40399923},
issn = {1476-4598},
support = {P2022R5TCA//PRIN, PROGETTI DI RICERCA DI RILEVANTE INTERESSE NAZIONALE/ ; 24718//AIRC IG/ ; },
mesh = {Humans ; *Biofilms/growth & development ; *Neoplasms/immunology/microbiology/etiology/pathology/metabolism ; *Microbiota/immunology ; Tumor Microenvironment/immunology ; Animals ; },
abstract = {Human-resident microbes typically cluster into biofilms - structurally organized communities embedded within a matrix of self-produced extracellular polymeric substance (EPS) that serves as a protective shield. These biofilms enhance microbial survival and functional adaptability, favoring a symbiotic relationship with the host under physiological conditions. However, biofilms exhibit a dual role in modulating the immune response. If their ability to promote tolerance is key to safeguarding homeostasis, by contrast, their persistence can overcome the cutting-edge balance resulting in immune evasion, chronic inflammation and development of numerous diseases such as cancer. Recent evidence highlights the significance of cancer-associated microbiota in shaping the tumor microenvironment (TME). These microbial inhabitants often exhibit biofilm-like structures, which may protect them from host immune responses and therapeutic interventions. The presence of biofilm-forming microbiota within the TME may promote chronic inflammation, and release of bioactive molecules that interfere with immune surveillance mechanisms, thereby enabling cancer cells to evade immune destruction. This review delves into the complex interplay between biofilms and cancer, with particular focus on the tumor-associated microbiota and the implications of biofilm involvement in modulating the immune landscape of the TME. Addressing this intricate relationship holds promises for innovative therapeutic approaches aimed at reprogramming the microbiota-cancer axis for better clinical outcomes.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
Humans
*Biofilms/growth & development
*Neoplasms/immunology/microbiology/etiology/pathology/metabolism
*Microbiota/immunology
Tumor Microenvironment/immunology
Animals
RevDate: 2025-05-21
Bacterial biofilm on peritoneal dialysis catheters: A retrospective observational study.
Peritoneal dialysis international : journal of the International Society for Peritoneal Dialysis [Epub ahead of print].
Objective: Biofilm formation significantly impacts infection risks in peritoneal dialysis (PD) patients. However, few studies focused on biofilms on PD catheters. This study aims to explore the formation and characteristics of bacterial biofilm on PD catheters. Methods: A retrospective study was conducted on maintenance PD patients from January 2007 to January 2024. We summarized the general characteristics of the patients, the reasons for catheter removal, scanning electron microscopy (SEM) results of the PD catheter, and bacterial culture results from the PD effluent. The selected patients were divided into two groups: catheter removal due to peritonitis group (20 cases) and catheter removal due to non-peritonitis group (8 cases). Results: (1) The average dialysis duration in catheter removal due to peritonitis group was 84.2 ± 46.6 months, significantly longer than that in catheter removal due to non-peritonitis group (21.8 ± 18.7 months). Thirteen patients (65.5%) in catheter removal due to peritonitis group had a history of peritonitis before the current episode, whereas none in catheter removal due to non-peritonitis group had experienced it previously (p = 0.002). (2) Bacterial biofilm was detected in 20 (71.4%) out of 28 patients. Of these, bacterial biofilm was found in 18 patients (90.0%) in catheter removal due to peritonitis group, compared to only 2 patients (25.0%) in catheter removal due to non-peritonitis group (p = 0.002). SEM revealed that the bacterial biofilm forms present on the PD catheters were exclusively cocci biofilms. The bacterial culture results from the PD fluid of patients in catheter removal due to peritonitis group indicated that the three most prevalent pathogens were Escherichia coli (7/20), methicillin-sensitive Staphylococcus aureus (3/20), and Staphylococcus epidermidis (3/20). Conclusion: Bacterial biofilm formation on PD catheters is common among long-term PD patients. It is important to note that not all PD catheters removed due to peritonitis exhibit bacterial biofilms, and such biofilms may also be present in patients without peritonitis.
Additional Links: PMID-40398648
Publisher:
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40398648,
year = {2025},
author = {Liu, A and Zhao, H and Wu, B and Zheng, S and Lu, L and Qiao, J and Chu, X and Men, C and He, Y and Zuo, L and Wang, M},
title = {Bacterial biofilm on peritoneal dialysis catheters: A retrospective observational study.},
journal = {Peritoneal dialysis international : journal of the International Society for Peritoneal Dialysis},
volume = {},
number = {},
pages = {8968608251331894},
doi = {10.1177/08968608251331894},
pmid = {40398648},
issn = {1718-4304},
abstract = {Objective: Biofilm formation significantly impacts infection risks in peritoneal dialysis (PD) patients. However, few studies focused on biofilms on PD catheters. This study aims to explore the formation and characteristics of bacterial biofilm on PD catheters. Methods: A retrospective study was conducted on maintenance PD patients from January 2007 to January 2024. We summarized the general characteristics of the patients, the reasons for catheter removal, scanning electron microscopy (SEM) results of the PD catheter, and bacterial culture results from the PD effluent. The selected patients were divided into two groups: catheter removal due to peritonitis group (20 cases) and catheter removal due to non-peritonitis group (8 cases). Results: (1) The average dialysis duration in catheter removal due to peritonitis group was 84.2 ± 46.6 months, significantly longer than that in catheter removal due to non-peritonitis group (21.8 ± 18.7 months). Thirteen patients (65.5%) in catheter removal due to peritonitis group had a history of peritonitis before the current episode, whereas none in catheter removal due to non-peritonitis group had experienced it previously (p = 0.002). (2) Bacterial biofilm was detected in 20 (71.4%) out of 28 patients. Of these, bacterial biofilm was found in 18 patients (90.0%) in catheter removal due to peritonitis group, compared to only 2 patients (25.0%) in catheter removal due to non-peritonitis group (p = 0.002). SEM revealed that the bacterial biofilm forms present on the PD catheters were exclusively cocci biofilms. The bacterial culture results from the PD fluid of patients in catheter removal due to peritonitis group indicated that the three most prevalent pathogens were Escherichia coli (7/20), methicillin-sensitive Staphylococcus aureus (3/20), and Staphylococcus epidermidis (3/20). Conclusion: Bacterial biofilm formation on PD catheters is common among long-term PD patients. It is important to note that not all PD catheters removed due to peritonitis exhibit bacterial biofilms, and such biofilms may also be present in patients without peritonitis.},
}
RevDate: 2025-05-21
Sequencing and genome-scale virulome reconstruction of Enterococcus faecalis clinical isolates delineate genes involved in gelatinase activity and biofilm formation.
Microbial pathogenesis pii:S0882-4010(25)00446-2 [Epub ahead of print].
INTRODUCTION: and gap statement: Enterococci are a leading cause of nosocomial infections with a wide array of virulence factors. Clinically isolated enterococci vary in gelatinase activity and biofilm-forming ability, yet the genetic basis for this variation is not fully understood.
AIM: This study aimed to identify genetic factors associated with the discrepancy in biofilm formation and gelatinase activity.
METHODS: Biofilm formation was quantified by the crystal violet assay and the gelatinase activity was determined on gelatin agar plates. The genomes of 33 clinical Enterococcus faecalis isolates were sequenced by Illumina HiSeq and annotated by the Rapid Annotations using Subsystems Technology tool kit (RASTtk) and tools within the Bacterial Viral Bioinfromatic Resource Center (BV-BRC). Virulence factors and prophages were predicted, and genotype-phenotype associations were statistically assessed.
RESULTS: All isolates formed biofilms with different intensities, with the majority (65%) forming moderate to strong biofilms. Gelatinase activity was detected in 39% of isolates. The hyaluronic acid precursor gene (EF0818), adhesion protein gene (prgB/asc10), manganese uptake gene (psaA), enterococcal surface protein gene (esp), and the complete capsule locus (cps) were significantly positively correlated with biofilm intensity (p < 0.05), while the quorum sensing genes, fsrA and fsrB, collagen adhesion gene (ace), and capsule gene, cpsF, were significantly positively correlated with gelatinase activity (p < 0.05). Prophage content was positively associated with biofilm formation.
CONCLUSION: Whole-genome sequencing identified genes and prophages linked to biofilm formation and gelatinase activity in Enterococcus faecalis. Future studies will experimentally confirm the role of identified genes in virulence and their possible anti-virulence intervention potential.
Additional Links: PMID-40398639
Publisher:
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40398639,
year = {2025},
author = {Abdelrahman, KA and Hashem, YA and Szubin, R and Monk, JM and Kashef, MT and Aziz, RK},
title = {Sequencing and genome-scale virulome reconstruction of Enterococcus faecalis clinical isolates delineate genes involved in gelatinase activity and biofilm formation.},
journal = {Microbial pathogenesis},
volume = {},
number = {},
pages = {107721},
doi = {10.1016/j.micpath.2025.107721},
pmid = {40398639},
issn = {1096-1208},
abstract = {INTRODUCTION: and gap statement: Enterococci are a leading cause of nosocomial infections with a wide array of virulence factors. Clinically isolated enterococci vary in gelatinase activity and biofilm-forming ability, yet the genetic basis for this variation is not fully understood.
AIM: This study aimed to identify genetic factors associated with the discrepancy in biofilm formation and gelatinase activity.
METHODS: Biofilm formation was quantified by the crystal violet assay and the gelatinase activity was determined on gelatin agar plates. The genomes of 33 clinical Enterococcus faecalis isolates were sequenced by Illumina HiSeq and annotated by the Rapid Annotations using Subsystems Technology tool kit (RASTtk) and tools within the Bacterial Viral Bioinfromatic Resource Center (BV-BRC). Virulence factors and prophages were predicted, and genotype-phenotype associations were statistically assessed.
RESULTS: All isolates formed biofilms with different intensities, with the majority (65%) forming moderate to strong biofilms. Gelatinase activity was detected in 39% of isolates. The hyaluronic acid precursor gene (EF0818), adhesion protein gene (prgB/asc10), manganese uptake gene (psaA), enterococcal surface protein gene (esp), and the complete capsule locus (cps) were significantly positively correlated with biofilm intensity (p < 0.05), while the quorum sensing genes, fsrA and fsrB, collagen adhesion gene (ace), and capsule gene, cpsF, were significantly positively correlated with gelatinase activity (p < 0.05). Prophage content was positively associated with biofilm formation.
CONCLUSION: Whole-genome sequencing identified genes and prophages linked to biofilm formation and gelatinase activity in Enterococcus faecalis. Future studies will experimentally confirm the role of identified genes in virulence and their possible anti-virulence intervention potential.},
}
RevDate: 2025-05-21
Designing of eucalyptol nanoemulsion drug delivery system loaded with amphotericin B for Candida albicans biofilm control: in vitro and in vivo assessment using the Galleria mellonella model.
Microbial pathogenesis pii:S0882-4010(25)00444-9 [Epub ahead of print].
OBJECTIVE: (s): Candida species can form biofilm in various clinical settings, making them challenging to treat due to their resistance to antifungal drugs. The present study aimed to evaluate the effects of eucalyptol/amphotericin B nanoemulsion (NEA) on Candida albicans (C. albicans) biofilm.
MATERIALS AND METHODS: In this study, NEA was synthesized and its capacity to combat biofilms generated by four clinical isolates and a reference strain of C. albicans was investigated according to CLSI M27-A3 guidelines. The NEA was prepared using eucalyptol oil, Tween 80, and ethanol, and characterized by measuring particle size, Z-potential, and encapsulation efficiency (EE %). The cytotoxicity study was performed on myeloblast KG1 cells and human RBCs. The gene assessment and molecular docking were conducted by Real-Time PCR and AutoDock Vina software, respectively. The in vivo stage was conducted on Galleria mellonella (G. mellonella) larvae, and ultimately, histopathological analysis was executed using H and E Staining.
RESULTS: Based on the results obtained, the NEA exhibited EE of 80% for Amphotericin B (AmB), displaying an average size of 39 nm and zeta potential of -2 mV. Minimum inhibitory concentration (MIC) and minimum biofilm inhibitory concentration (MBIC) revealed more efficiency to inhibit biofilms (MIC Geomean=4.25 μg/mL, MBIC Geomean=19.58 μg/mL) compared to AmB (MIC Geomean=17.05 μg/mL, MBIC Geomean=59.37 μg/mL). While ALS1 and HWP1 gene expression remained unchanged, molecular docking suggested the binding of eucalyptol to ALS1 and HWP1 proteins. The results of FE-SEM demonstrated the biofilm destruction through yeast bursting and cytoplasm leakage. The NEA, in comparison to AmB, decreased melanization in tissue sections and also enhanced the survival of G. melonella larvae.
CONCLUSION: The NEA exhibited superior biocompatibility toward the KG1 myeloblasts cell line and RBCs cells additionally enhances the survival rate of G. mellonella larvae compared to AmB. Overall, NEA proved an efficient nano-formulated product against C. albicans biofilms.
Additional Links: PMID-40398638
Publisher:
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40398638,
year = {2025},
author = {Keymaram, M and Lotfali, E and Mousazadeh, M and Nikkhah, M and Raiesi, O and Yadegari, MH},
title = {Designing of eucalyptol nanoemulsion drug delivery system loaded with amphotericin B for Candida albicans biofilm control: in vitro and in vivo assessment using the Galleria mellonella model.},
journal = {Microbial pathogenesis},
volume = {},
number = {},
pages = {107719},
doi = {10.1016/j.micpath.2025.107719},
pmid = {40398638},
issn = {1096-1208},
abstract = {OBJECTIVE: (s): Candida species can form biofilm in various clinical settings, making them challenging to treat due to their resistance to antifungal drugs. The present study aimed to evaluate the effects of eucalyptol/amphotericin B nanoemulsion (NEA) on Candida albicans (C. albicans) biofilm.
MATERIALS AND METHODS: In this study, NEA was synthesized and its capacity to combat biofilms generated by four clinical isolates and a reference strain of C. albicans was investigated according to CLSI M27-A3 guidelines. The NEA was prepared using eucalyptol oil, Tween 80, and ethanol, and characterized by measuring particle size, Z-potential, and encapsulation efficiency (EE %). The cytotoxicity study was performed on myeloblast KG1 cells and human RBCs. The gene assessment and molecular docking were conducted by Real-Time PCR and AutoDock Vina software, respectively. The in vivo stage was conducted on Galleria mellonella (G. mellonella) larvae, and ultimately, histopathological analysis was executed using H and E Staining.
RESULTS: Based on the results obtained, the NEA exhibited EE of 80% for Amphotericin B (AmB), displaying an average size of 39 nm and zeta potential of -2 mV. Minimum inhibitory concentration (MIC) and minimum biofilm inhibitory concentration (MBIC) revealed more efficiency to inhibit biofilms (MIC Geomean=4.25 μg/mL, MBIC Geomean=19.58 μg/mL) compared to AmB (MIC Geomean=17.05 μg/mL, MBIC Geomean=59.37 μg/mL). While ALS1 and HWP1 gene expression remained unchanged, molecular docking suggested the binding of eucalyptol to ALS1 and HWP1 proteins. The results of FE-SEM demonstrated the biofilm destruction through yeast bursting and cytoplasm leakage. The NEA, in comparison to AmB, decreased melanization in tissue sections and also enhanced the survival of G. melonella larvae.
CONCLUSION: The NEA exhibited superior biocompatibility toward the KG1 myeloblasts cell line and RBCs cells additionally enhances the survival rate of G. mellonella larvae compared to AmB. Overall, NEA proved an efficient nano-formulated product against C. albicans biofilms.},
}
RevDate: 2025-05-21
Antimicrobial resistance, biofilm formation, and presence of colistin resistance mcr genes in Escherichia coli and Aeromonas spp. isolated from water samples.
Microbial pathogenesis pii:S0882-4010(25)00441-3 [Epub ahead of print].
This study investigated the presence of Klebsiella pneumonia, Salmonella spp., Aeromonas spp., and Escherichia coli. Within the scope of the study, between November 2020 and September 2022, 600 water samples (springs, ponds, and drinking waters) were used as materials. Isolation and identification tests were performed to investigate the presence of Salmonella spp., Aeromonas spp., and E. coli through MALDI-TOF (Matrix-assisted Laser Desorption Ionization Time-of-Flight). K. pneumonia, P. aeruginosa, and Salmonella spp. were not found in any isolate. However, Aeromonas spp., and E. coli were found at 1% (8/600) and 2% (14/600), respectively. Aeromonas spp. isolates were identified as 1.5 (4/600) A. veronii, 0.5 (3/600) A. media and 0.1 (1/600) A. caviae. The biofilm-forming ability was observed in 14 (100%) of 14 E. coli strains with the microplate method. Out of 14 biofilm-forming E. coli strains, 2 (14%) demonstrated strong, 10 (71%) moderate, and 2 (14%) weak production. Moreover, out of 8 biofilms forming Aeromonas spp. strains, 3 (37,5%) demonstrated strong, 3 (37,5%) moderate, and 2 (25%) weak production. Colistin-related genes (mcr-3/7, 1/2/6, mcr-4, mcr-5 and mcr-8) were identified by Real-Time PCR. As a result of real time PCR, Aeromonas spp. it was determined that 37% (3/8) of the isolates carried the mcr-3/7 gene. It was determined that A. veronii and A. media carried the mcr-3/7 gene at rates of 66% (2/3) and 33% (1/3). However, mcr-1/2/6, mcr-4, mcr-5 and mcr-8 genes were not found in the examined Aeromonas spp. isolates. Hereby, factors that play a role in the emergence and spread of antibiotic-resistant strains should be identified, and necessary precautions should be taken.
Additional Links: PMID-40398636
Publisher:
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40398636,
year = {2025},
author = {Barel, M and Koskeroglu, K and Hizlisoy, H and Arslan, RS and Hizlisoy, S},
title = {Antimicrobial resistance, biofilm formation, and presence of colistin resistance mcr genes in Escherichia coli and Aeromonas spp. isolated from water samples.},
journal = {Microbial pathogenesis},
volume = {},
number = {},
pages = {107716},
doi = {10.1016/j.micpath.2025.107716},
pmid = {40398636},
issn = {1096-1208},
abstract = {This study investigated the presence of Klebsiella pneumonia, Salmonella spp., Aeromonas spp., and Escherichia coli. Within the scope of the study, between November 2020 and September 2022, 600 water samples (springs, ponds, and drinking waters) were used as materials. Isolation and identification tests were performed to investigate the presence of Salmonella spp., Aeromonas spp., and E. coli through MALDI-TOF (Matrix-assisted Laser Desorption Ionization Time-of-Flight). K. pneumonia, P. aeruginosa, and Salmonella spp. were not found in any isolate. However, Aeromonas spp., and E. coli were found at 1% (8/600) and 2% (14/600), respectively. Aeromonas spp. isolates were identified as 1.5 (4/600) A. veronii, 0.5 (3/600) A. media and 0.1 (1/600) A. caviae. The biofilm-forming ability was observed in 14 (100%) of 14 E. coli strains with the microplate method. Out of 14 biofilm-forming E. coli strains, 2 (14%) demonstrated strong, 10 (71%) moderate, and 2 (14%) weak production. Moreover, out of 8 biofilms forming Aeromonas spp. strains, 3 (37,5%) demonstrated strong, 3 (37,5%) moderate, and 2 (25%) weak production. Colistin-related genes (mcr-3/7, 1/2/6, mcr-4, mcr-5 and mcr-8) were identified by Real-Time PCR. As a result of real time PCR, Aeromonas spp. it was determined that 37% (3/8) of the isolates carried the mcr-3/7 gene. It was determined that A. veronii and A. media carried the mcr-3/7 gene at rates of 66% (2/3) and 33% (1/3). However, mcr-1/2/6, mcr-4, mcr-5 and mcr-8 genes were not found in the examined Aeromonas spp. isolates. Hereby, factors that play a role in the emergence and spread of antibiotic-resistant strains should be identified, and necessary precautions should be taken.},
}
RevDate: 2025-05-21
Core-Shell ZnO2@Cerium-Based Metal-Organic Framework with Low Turnover, Dual-Catalytic Activity for Biosafe Biofilm Dispersal and Immune Modulation.
ACS applied materials & interfaces [Epub ahead of print].
The era of relying on antibiotics for curing bacterial infections is rapidly approaching an end, necessitating development of non-antibiotic-based infection-control strategies. Dispersal of infectious biofilms is a potential strategy but yields dispersed bacteria in blood that may cause sepsis. We report a bromide-loaded, core-shell ZnO2-nanoparticle/Ce-based metal-organic framework (ZnO2@CeMOF/Br) of which the ZnO2 core degrades at pH ≤ 6.5, leaving the MOF's Ce node intact. ZnO2-core degradation initially generates a nonradical, relatively stable, low-oxidative hydrogen peroxide that can cleave matrix DNA causing dispersal of Staphylococcus aureus biofilms and reacts with bromide ions to form transient hypobromous acid. Hypobromous acid modulates macrophage polarization toward an M1-like phenotype to clear dispersed bacteria from blood. Subsequently the Ce[3+]/Ce[4+] redox couple forming the Ce node acts as an electron shuttle upon oxidation/reduction to faciltate two catalytic reactions, maintaining hydrolysis of phosphodiester bonds and associated cleavage of matrix DNA as well as modulation of macrophage polarization. Neither growth of tissue cells or macrophages nor hemolysis are negatively affected by exposure to ZnO2@CeMOF/Br nanocatalysts at a ZnO2 nanoparticle over CeMOFs weight ratio ≤ 1.2, up until CeMOF concentrations less than at least 180 μg/mL. Under biosafe, low-turnover catalytic conditions, irrigation of infected wounds in diabetic mice with ZnO2@CeMOF/Br nanocatalysts (90 μg/mL) results in 100% survival, fast recovery of healthy body temperature and weight, lower numbers of CFUs in blood and wound and organ tissues, and macrophage polarization toward an M1-like phenotype, demonstrating potential of ZnO2@CeMOF/Br nanocatalysts for non-antibiotic-based infection control.
Additional Links: PMID-40397809
Publisher:
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40397809,
year = {2025},
author = {Wu, R and Ge, T and Yu, T and Shi, Q and Shi, R and Ren, Y and Busscher, HJ and Liu, J and van der Mei, HC},
title = {Core-Shell ZnO2@Cerium-Based Metal-Organic Framework with Low Turnover, Dual-Catalytic Activity for Biosafe Biofilm Dispersal and Immune Modulation.},
journal = {ACS applied materials & interfaces},
volume = {},
number = {},
pages = {},
doi = {10.1021/acsami.5c08974},
pmid = {40397809},
issn = {1944-8252},
abstract = {The era of relying on antibiotics for curing bacterial infections is rapidly approaching an end, necessitating development of non-antibiotic-based infection-control strategies. Dispersal of infectious biofilms is a potential strategy but yields dispersed bacteria in blood that may cause sepsis. We report a bromide-loaded, core-shell ZnO2-nanoparticle/Ce-based metal-organic framework (ZnO2@CeMOF/Br) of which the ZnO2 core degrades at pH ≤ 6.5, leaving the MOF's Ce node intact. ZnO2-core degradation initially generates a nonradical, relatively stable, low-oxidative hydrogen peroxide that can cleave matrix DNA causing dispersal of Staphylococcus aureus biofilms and reacts with bromide ions to form transient hypobromous acid. Hypobromous acid modulates macrophage polarization toward an M1-like phenotype to clear dispersed bacteria from blood. Subsequently the Ce[3+]/Ce[4+] redox couple forming the Ce node acts as an electron shuttle upon oxidation/reduction to faciltate two catalytic reactions, maintaining hydrolysis of phosphodiester bonds and associated cleavage of matrix DNA as well as modulation of macrophage polarization. Neither growth of tissue cells or macrophages nor hemolysis are negatively affected by exposure to ZnO2@CeMOF/Br nanocatalysts at a ZnO2 nanoparticle over CeMOFs weight ratio ≤ 1.2, up until CeMOF concentrations less than at least 180 μg/mL. Under biosafe, low-turnover catalytic conditions, irrigation of infected wounds in diabetic mice with ZnO2@CeMOF/Br nanocatalysts (90 μg/mL) results in 100% survival, fast recovery of healthy body temperature and weight, lower numbers of CFUs in blood and wound and organ tissues, and macrophage polarization toward an M1-like phenotype, demonstrating potential of ZnO2@CeMOF/Br nanocatalysts for non-antibiotic-based infection control.},
}
RevDate: 2025-05-21
Comparative proteomics of biofilm development in Pseudoalteromonas tunicata discovers a distinct family of Ca[2+]-dependent adhesins.
mBio [Epub ahead of print].
UNLABELLED: The marine bacterium, Pseudoalteromonas tunicata, is a useful model for studying biofilm development due to its ability to colonize and form biofilms on a variety of marine and eukaryotic host-associated surfaces. However, the pathways responsible for P. tunicata biofilm formation are not fully understood, in part due to a lack of functional information for a large proportion of its proteome. We used comparative shotgun proteomics to explore P. tunicata biofilm development from the planktonic phase throughout early, middle, and late biofilm stages. A total of 248 biofilm-associated proteins were identified, including many hypothetical proteins, as well as previously known P. tunicata biofilm-related proteins, such as the autocidal enzyme AlpP, violacein proteins, S-layer protein SLR4, and various pili proteins. We further investigated the top identified biofilm-associated protein, a previously uncharacterized 1,600-amino acid protein (EAR30327), which we designate as "BapP." Based on AlphaFold modeling and genomic context analysis, we predicted BapP as a distinct Ca[2+]-dependent biofilm adhesin. Consistent with this prediction, a ΔbapP knockout mutant was defective in forming both pellicle- and surface-associated biofilms and rescued by re-insertion of bapP into the genome. Similar to the mechanisms of RTX Bap-like adhesins, BapP-mediated biofilm formation was influenced by Ca[2+] levels, and BapP is potentially exported by a Type 1 secretion system. Ultimately, our work not only provides a useful proteomic data set for studying biofilm development in an ecologically relevant organism but also adds to our knowledge of bacterial adhesin diversity, emphasizing Bap-like proteins as widespread determinants of biofilm formation in bacteria.
IMPORTANCE: Understanding how bacteria form biofilms is essential because biofilms play a crucial role in bacterial survival and interaction with their environments. The marine bacterium Pseudoalteromonas tunicata is a valuable model for studying biofilm formation, as it colonizes diverse marine surfaces and host organisms. By identifying proteins involved in biofilm development, our study sheds light on the specific proteins that help P. tunicata transition from a free-swimming state to a stable biofilm. This work highlights the role of a large, calcium-dependent protein, BapP, which we found to be essential for biofilm stability and structure. This protein and hundreds of others identified provide new insights into bacterial adhesion mechanisms, expanding our understanding of biofilm formation in marine environments and potentially informing broader studies on biofilm-related processes in other bacteria.
Additional Links: PMID-40396756
Publisher:
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40396756,
year = {2025},
author = {Ali, S and Stavropoulos, A and Jenkins, B and Graves, S and Ahmadi, A and Marzbanrad, V and Che, G and Cheng, J and Tan, H and Wei, X and Egan, S and Ingalls, B and Neufeld, JD and Eckhard, U and Charles, TC and Doxey, AC},
title = {Comparative proteomics of biofilm development in Pseudoalteromonas tunicata discovers a distinct family of Ca[2+]-dependent adhesins.},
journal = {mBio},
volume = {},
number = {},
pages = {e0106925},
doi = {10.1128/mbio.01069-25},
pmid = {40396756},
issn = {2150-7511},
abstract = {UNLABELLED: The marine bacterium, Pseudoalteromonas tunicata, is a useful model for studying biofilm development due to its ability to colonize and form biofilms on a variety of marine and eukaryotic host-associated surfaces. However, the pathways responsible for P. tunicata biofilm formation are not fully understood, in part due to a lack of functional information for a large proportion of its proteome. We used comparative shotgun proteomics to explore P. tunicata biofilm development from the planktonic phase throughout early, middle, and late biofilm stages. A total of 248 biofilm-associated proteins were identified, including many hypothetical proteins, as well as previously known P. tunicata biofilm-related proteins, such as the autocidal enzyme AlpP, violacein proteins, S-layer protein SLR4, and various pili proteins. We further investigated the top identified biofilm-associated protein, a previously uncharacterized 1,600-amino acid protein (EAR30327), which we designate as "BapP." Based on AlphaFold modeling and genomic context analysis, we predicted BapP as a distinct Ca[2+]-dependent biofilm adhesin. Consistent with this prediction, a ΔbapP knockout mutant was defective in forming both pellicle- and surface-associated biofilms and rescued by re-insertion of bapP into the genome. Similar to the mechanisms of RTX Bap-like adhesins, BapP-mediated biofilm formation was influenced by Ca[2+] levels, and BapP is potentially exported by a Type 1 secretion system. Ultimately, our work not only provides a useful proteomic data set for studying biofilm development in an ecologically relevant organism but also adds to our knowledge of bacterial adhesin diversity, emphasizing Bap-like proteins as widespread determinants of biofilm formation in bacteria.
IMPORTANCE: Understanding how bacteria form biofilms is essential because biofilms play a crucial role in bacterial survival and interaction with their environments. The marine bacterium Pseudoalteromonas tunicata is a valuable model for studying biofilm formation, as it colonizes diverse marine surfaces and host organisms. By identifying proteins involved in biofilm development, our study sheds light on the specific proteins that help P. tunicata transition from a free-swimming state to a stable biofilm. This work highlights the role of a large, calcium-dependent protein, BapP, which we found to be essential for biofilm stability and structure. This protein and hundreds of others identified provide new insights into bacterial adhesion mechanisms, expanding our understanding of biofilm formation in marine environments and potentially informing broader studies on biofilm-related processes in other bacteria.},
}
RevDate: 2025-05-21
Synergistic treatment of linoleic acid and cefazolin on Staphylococcus aureus biofilm-related catheter infections.
Applied and environmental microbiology [Epub ahead of print].
Staphylococcus aureus is a human pathogen that causes severe infections through biofilm formation. S. aureus biofilm is particularly susceptible to catheters in patients undergoing peritoneal dialysis. Although antibiotics are used to treat catheter infections, high-concentration treatments adversely affect human host immune systems and change the physicochemical properties of the catheters. To improve therapeutic outcomes without side effects, we combined antibiotics and natural products. In this study, we propose a combination of linoleic acid (LA) and cefazolin (CFZ) to treat S. aureus infections synergistically and apply it to catheter environments and in vivo systems. LA is a polyunsaturated fatty acid derived from natural products, and CFZ is a major antibiotic used to treat S. aureus catheter-related infections. The optimum synergistic condition was determined using silicon pad-forming biofilm similar to catheter materials. S. aureus biofilms were considerably inhibited in vitro and in vivo owing to the improved antibacterial effects. Furthermore, the combination negatively regulated the chemokine levels in the peritoneum, kidney, and liver extracted from mouse models. Moreover, it did not affect the cytotoxicity of human omentum mesothelial cells and the functions of the kidney and liver. Therefore, the combination of LA and CFZ could be a potential synergistic therapy for S. aureus catheter infections.IMPORTANCECatheter contamination is commonly caused by Staphylococcus aureus biofilm formation, primarily in peritoneal dialysis patients. Although antibiotics are used to treat catheter infections, high concentrations of antibiotics impair the immune system of the human host and alter the physicochemical properties of catheters. Therefore, it is crucial to improve therapeutic outcomes while minimizing the side effects of antibiotics. Combined treatments with natural products can be solutions to alleviate these problems. Our study offers a new synergistic combination (linoleic acid and cefazolin) for the control of catheter infections caused by S. aureus biofilms, especially in peritoneal dialysis.
Additional Links: PMID-40396720
Publisher:
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40396720,
year = {2025},
author = {Ham, S and Kim, H-S and Jo, MJ and Cha, E and Ryoo, H-S and Kim, H and Lee, H and Ko, G-J and Park, H-D},
title = {Synergistic treatment of linoleic acid and cefazolin on Staphylococcus aureus biofilm-related catheter infections.},
journal = {Applied and environmental microbiology},
volume = {},
number = {},
pages = {e0077025},
doi = {10.1128/aem.00770-25},
pmid = {40396720},
issn = {1098-5336},
abstract = {Staphylococcus aureus is a human pathogen that causes severe infections through biofilm formation. S. aureus biofilm is particularly susceptible to catheters in patients undergoing peritoneal dialysis. Although antibiotics are used to treat catheter infections, high-concentration treatments adversely affect human host immune systems and change the physicochemical properties of the catheters. To improve therapeutic outcomes without side effects, we combined antibiotics and natural products. In this study, we propose a combination of linoleic acid (LA) and cefazolin (CFZ) to treat S. aureus infections synergistically and apply it to catheter environments and in vivo systems. LA is a polyunsaturated fatty acid derived from natural products, and CFZ is a major antibiotic used to treat S. aureus catheter-related infections. The optimum synergistic condition was determined using silicon pad-forming biofilm similar to catheter materials. S. aureus biofilms were considerably inhibited in vitro and in vivo owing to the improved antibacterial effects. Furthermore, the combination negatively regulated the chemokine levels in the peritoneum, kidney, and liver extracted from mouse models. Moreover, it did not affect the cytotoxicity of human omentum mesothelial cells and the functions of the kidney and liver. Therefore, the combination of LA and CFZ could be a potential synergistic therapy for S. aureus catheter infections.IMPORTANCECatheter contamination is commonly caused by Staphylococcus aureus biofilm formation, primarily in peritoneal dialysis patients. Although antibiotics are used to treat catheter infections, high concentrations of antibiotics impair the immune system of the human host and alter the physicochemical properties of catheters. Therefore, it is crucial to improve therapeutic outcomes while minimizing the side effects of antibiotics. Combined treatments with natural products can be solutions to alleviate these problems. Our study offers a new synergistic combination (linoleic acid and cefazolin) for the control of catheter infections caused by S. aureus biofilms, especially in peritoneal dialysis.},
}
RevDate: 2025-05-22
Impact of Pseudomonas aeruginosa biofilm formation by different sequence types on treating lower limb vascular infections.
Current research in microbial sciences, 8:100379.
Pseudomonas aeruginosa is a major contributor to persistent chronic infections in clinical practice, owing to its robust biofilm formation capacity and frequent antimicrobial resistance acquisition. However, most current studies focus on single strains and thus overlook phenotypic differences among coexisting strains within the same host. With that in mind, we proposed a hypothesis that P. aeruginosa strains from the same patient, yet with distinct genetic backgrounds, might exhibit differing resistance profiles and virulence genes. To test this hypothesis, we selected three strains with different sequence types (STs), all isolated from the chronic wounds of a patient with long-term bilateral lower limb infections. By employing multilocus sequence typing, antimicrobial susceptibility testing, biofilm gene quantification, growth kinetics assays, Galleria mellonella virulence experiments, and phylogenetic reconstruction, we systematically evaluated the relationships between these strains'biofilm formation and virulence. The results revealed significant genetic diversity and evolutionary origin variations among the three strains. Notably, ST2584 (WYDPA-23-3) exhibited multidrug resistance (resistant to 7 of the 12 tested antibiotics) and the highest growth rate, whereas ST270 (WYDPA-23-2)-despite the downregulation of pelA, a gene linked to extracellular matrix biogenesis-demonstrated a 2.3-fold increase in biofilm formation and the highest larval lethality. By comparing multiple strains coexisting in the same host, this study further elucidates the role of P. aeruginosa biofilm in sustaining chronic infections and offers valuable guidance for optimizing clinical treatment strategies and antibiotic selection. In light of these findings, developing rapid and precise biofilm detection methods and designing innovative drugs targeting high biofilm-producing strains should be prioritized.
Additional Links: PMID-40395473
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40395473,
year = {2025},
author = {Wang, Y and Xiao, Q and Yang, Q and Long, Y and Jiang, Z and Zhang, T and Hu, Y and Gao, B and Chen, X and Wang, T and Xiao, L},
title = {Impact of Pseudomonas aeruginosa biofilm formation by different sequence types on treating lower limb vascular infections.},
journal = {Current research in microbial sciences},
volume = {8},
number = {},
pages = {100379},
pmid = {40395473},
issn = {2666-5174},
abstract = {Pseudomonas aeruginosa is a major contributor to persistent chronic infections in clinical practice, owing to its robust biofilm formation capacity and frequent antimicrobial resistance acquisition. However, most current studies focus on single strains and thus overlook phenotypic differences among coexisting strains within the same host. With that in mind, we proposed a hypothesis that P. aeruginosa strains from the same patient, yet with distinct genetic backgrounds, might exhibit differing resistance profiles and virulence genes. To test this hypothesis, we selected three strains with different sequence types (STs), all isolated from the chronic wounds of a patient with long-term bilateral lower limb infections. By employing multilocus sequence typing, antimicrobial susceptibility testing, biofilm gene quantification, growth kinetics assays, Galleria mellonella virulence experiments, and phylogenetic reconstruction, we systematically evaluated the relationships between these strains'biofilm formation and virulence. The results revealed significant genetic diversity and evolutionary origin variations among the three strains. Notably, ST2584 (WYDPA-23-3) exhibited multidrug resistance (resistant to 7 of the 12 tested antibiotics) and the highest growth rate, whereas ST270 (WYDPA-23-2)-despite the downregulation of pelA, a gene linked to extracellular matrix biogenesis-demonstrated a 2.3-fold increase in biofilm formation and the highest larval lethality. By comparing multiple strains coexisting in the same host, this study further elucidates the role of P. aeruginosa biofilm in sustaining chronic infections and offers valuable guidance for optimizing clinical treatment strategies and antibiotic selection. In light of these findings, developing rapid and precise biofilm detection methods and designing innovative drugs targeting high biofilm-producing strains should be prioritized.},
}
RevDate: 2025-05-20
Chemical Elements and Thickness of Candida albicans Biofilm Induced by Glucose, Lactose, Protein, and Iron.
European journal of dentistry [Epub ahead of print].
Health is the most important aspect that needs to be considered, and the oral cavity cannot be separated from other parts. Candida albicans is a normal flora in the oral cavity that is a major cause of oral candidiasis. Research on biofilms can help prevent oral candidiasis infection in the community. Biofilms are involved in the pathogenesis and could be examined using an electron and fluorescence microscope, which can analyze the whole biofilm in actual conditions. This study aims to determine the chemical elements and thickness of Candida albicans biofilms induced by glucose, lactose, soy protein, and iron.This analytic observational study was carried out by observing the chemical elements and thickness of the biofilm by scanning electron microscopy with energy dispersive X-ray (SEM-EDX) and confocal laser scanning microscopy (CLSM). SEM-EDX data analysis used the EDAX APEX software and CLSM used the Olympus FluoView ver 4.2.a.SEM-EDX examination showed the formation of Candida albicans biofilm induced by glucose, lactose, soy protein, and iron with similarity in the percentage of the most constituent chemical elements, namely, oxygen, carbon, nitrogen, and phosphorus, and the least were sulfur. The thickest biofilm was found in the induction of iron, glucose, and lactose, and the thinnest was soy protein.The chemical elements of Candida albicans biofilm induced by four different inducers has the same percentage of the composition of elements, namely, oxygen, carbon, nitrogen, and phosphorus, and the least were sulfur and the thickest biofilm was by the induction of iron, glucose, and lactose, and the thinnest was by soy protein.
Additional Links: PMID-40393664
Publisher:
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40393664,
year = {2025},
author = {Kriswandini, IL and Sidarningsih, S and Nuraini, P and Y, NMD and Aljunaid, MA and Fadhila, O},
title = {Chemical Elements and Thickness of Candida albicans Biofilm Induced by Glucose, Lactose, Protein, and Iron.},
journal = {European journal of dentistry},
volume = {},
number = {},
pages = {},
doi = {10.1055/s-0045-1808261},
pmid = {40393664},
issn = {1305-7456},
abstract = {Health is the most important aspect that needs to be considered, and the oral cavity cannot be separated from other parts. Candida albicans is a normal flora in the oral cavity that is a major cause of oral candidiasis. Research on biofilms can help prevent oral candidiasis infection in the community. Biofilms are involved in the pathogenesis and could be examined using an electron and fluorescence microscope, which can analyze the whole biofilm in actual conditions. This study aims to determine the chemical elements and thickness of Candida albicans biofilms induced by glucose, lactose, soy protein, and iron.This analytic observational study was carried out by observing the chemical elements and thickness of the biofilm by scanning electron microscopy with energy dispersive X-ray (SEM-EDX) and confocal laser scanning microscopy (CLSM). SEM-EDX data analysis used the EDAX APEX software and CLSM used the Olympus FluoView ver 4.2.a.SEM-EDX examination showed the formation of Candida albicans biofilm induced by glucose, lactose, soy protein, and iron with similarity in the percentage of the most constituent chemical elements, namely, oxygen, carbon, nitrogen, and phosphorus, and the least were sulfur. The thickest biofilm was found in the induction of iron, glucose, and lactose, and the thinnest was soy protein.The chemical elements of Candida albicans biofilm induced by four different inducers has the same percentage of the composition of elements, namely, oxygen, carbon, nitrogen, and phosphorus, and the least were sulfur and the thickest biofilm was by the induction of iron, glucose, and lactose, and the thinnest was by soy protein.},
}
RevDate: 2025-05-20
Algae Biofilm Produces Less Microbe-Derived Dissolved Organic Nitrogen Under Higher C/N Ratio Conditions.
Environmental research pii:S0013-9351(25)01148-X [Epub ahead of print].
The increased release of microbe-derived dissolved organic nitrogen (mDON) during biological nutrient removal (BNR) processes, particularly under carbon dosing conditions, has emerged as a primary cause to eutrophication. Although algae biofilm (AB) has potential in mitigating mDON discharge, the influence of wastewater carbon-to-nitrogen (C/N) ratios on mDON formation remains poorly understood. Here, we investigated AB's mDON formation and utilization performance, molecular characteristics, and metabolic traits under C/N ratios ranging from 1 to 8. All AB reactors reached mDON concentrations < 1.3 mg/L, presenting a trend of first rising and then falling as C/N ratios rose. At the highest C/N ratio, AB effectively reduced mDON concentrations to 0.88 ± 0.08 mg/L, representing a reduction greater than 50% compared to conventional BNR processes, and achieved a total nitrogen removal efficiency of 97.19%. Redundancy and network analysis revealed that dominant algae (Chlorophyta and Cyanobacteria) and bacteria (Bacteroidota and Proteobacteria) exhibited distinct mDON production and utilization patterns across different C/N ratios. Algae proliferated under higher C/N ratios promoted the synergistic algal-bacteria interactions, enabling labile DON recycling and reducing its chemodiversity. This was also supported by the increased genetic investments in DON metabolism under higher C/N ratios. Conversely, bacterial activity, responsible for diversifying mDON pools via cross-module transformation reactions, was inhibited under elevated C/N ratios. Overall, AB is demonstrated robust for DON-related eutrophication control, even under high C/N ratios. This study first investigates the effects of C/N ratios on the mDON fates within algae biofilm systems and reveals the taxon-specific formation and utilization patterns.
Additional Links: PMID-40393536
Publisher:
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40393536,
year = {2025},
author = {Yu, Y and Lin, Y and Gu, C and Man, F and Ma, S and Xue, Y and Ren, H and Xu, K},
title = {Algae Biofilm Produces Less Microbe-Derived Dissolved Organic Nitrogen Under Higher C/N Ratio Conditions.},
journal = {Environmental research},
volume = {},
number = {},
pages = {121897},
doi = {10.1016/j.envres.2025.121897},
pmid = {40393536},
issn = {1096-0953},
abstract = {The increased release of microbe-derived dissolved organic nitrogen (mDON) during biological nutrient removal (BNR) processes, particularly under carbon dosing conditions, has emerged as a primary cause to eutrophication. Although algae biofilm (AB) has potential in mitigating mDON discharge, the influence of wastewater carbon-to-nitrogen (C/N) ratios on mDON formation remains poorly understood. Here, we investigated AB's mDON formation and utilization performance, molecular characteristics, and metabolic traits under C/N ratios ranging from 1 to 8. All AB reactors reached mDON concentrations < 1.3 mg/L, presenting a trend of first rising and then falling as C/N ratios rose. At the highest C/N ratio, AB effectively reduced mDON concentrations to 0.88 ± 0.08 mg/L, representing a reduction greater than 50% compared to conventional BNR processes, and achieved a total nitrogen removal efficiency of 97.19%. Redundancy and network analysis revealed that dominant algae (Chlorophyta and Cyanobacteria) and bacteria (Bacteroidota and Proteobacteria) exhibited distinct mDON production and utilization patterns across different C/N ratios. Algae proliferated under higher C/N ratios promoted the synergistic algal-bacteria interactions, enabling labile DON recycling and reducing its chemodiversity. This was also supported by the increased genetic investments in DON metabolism under higher C/N ratios. Conversely, bacterial activity, responsible for diversifying mDON pools via cross-module transformation reactions, was inhibited under elevated C/N ratios. Overall, AB is demonstrated robust for DON-related eutrophication control, even under high C/N ratios. This study first investigates the effects of C/N ratios on the mDON fates within algae biofilm systems and reveals the taxon-specific formation and utilization patterns.},
}
RevDate: 2025-05-20
DNA duplication in Burkholderia thailandensis induces biofilm formation by activating a two-component regulatory system.
PLoS genetics, 21(5):e1011528 pii:PGENETICS-D-24-01441 [Epub ahead of print].
Burkholderia thailandensis strain E264 (BtE264) and close relatives stochastically duplicate a 208.6 kb region of chromosome I via RecA-dependent recombination between two nearly identical insertion sequence elements. Because homologous recombination occurs at a constant, low level, populations of BtE264 are always heterogeneous, but cells containing two or more copies of the region (Dup+) have an advantage, and hence predominate, during biofilm growth, while those with a single copy (Dup-) are favored during planktonic growth. Moreover, only Dup+ bacteria form 'efficient' biofilms within 24 hours in liquid medium. We determined that duplicate copies of a subregion containing genes encoding an archaic chaperone-usher pathway pilus (csuFABCDE) and a two-component regulatory system (bfmSR) are necessary and sufficient for generating efficient biofilms and for conferring a selective advantage during biofilm growth. BfmSR functionality is required, as deletion of either bfmS or bfmR, or a mutation predicted to abrogate phosphorylation of BfmR, abrogates biofilm formation. However, duplicate copies of the csuFABCDE genes are not required. Instead, we found that BfmSR controls expression of csuFABCDE and bfmSR by activating a promoter upstream of csuF during biofilm growth or when the 208.6 kb region, or just bfmSR, are duplicated. Single cell analyses showed that duplication of the 208.6 kb region is sufficient to activate BfmSR in 75% of bacteria during planktonic (BfmSR 'OFF') growth conditions. Together, our data indicate that the combination of deterministic two-component signal transduction and stochastic, duplication-mediated activation of that TCS form a bet-hedging strategy that allows BtE264 to survive when conditions shift rapidly from those favoring planktonic growth to those requiring biofilm formation, such as may be encountered in the soils of Southeast Asia and Northern Australia. Our data highlight the positive impact that transposable elements can have on the evolution of bacterial populations.
Additional Links: PMID-40392945
Publisher:
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40392945,
year = {2025},
author = {Lowrey, LC and Mote, KB and Cotter, PA},
title = {DNA duplication in Burkholderia thailandensis induces biofilm formation by activating a two-component regulatory system.},
journal = {PLoS genetics},
volume = {21},
number = {5},
pages = {e1011528},
doi = {10.1371/journal.pgen.1011528},
pmid = {40392945},
issn = {1553-7404},
abstract = {Burkholderia thailandensis strain E264 (BtE264) and close relatives stochastically duplicate a 208.6 kb region of chromosome I via RecA-dependent recombination between two nearly identical insertion sequence elements. Because homologous recombination occurs at a constant, low level, populations of BtE264 are always heterogeneous, but cells containing two or more copies of the region (Dup+) have an advantage, and hence predominate, during biofilm growth, while those with a single copy (Dup-) are favored during planktonic growth. Moreover, only Dup+ bacteria form 'efficient' biofilms within 24 hours in liquid medium. We determined that duplicate copies of a subregion containing genes encoding an archaic chaperone-usher pathway pilus (csuFABCDE) and a two-component regulatory system (bfmSR) are necessary and sufficient for generating efficient biofilms and for conferring a selective advantage during biofilm growth. BfmSR functionality is required, as deletion of either bfmS or bfmR, or a mutation predicted to abrogate phosphorylation of BfmR, abrogates biofilm formation. However, duplicate copies of the csuFABCDE genes are not required. Instead, we found that BfmSR controls expression of csuFABCDE and bfmSR by activating a promoter upstream of csuF during biofilm growth or when the 208.6 kb region, or just bfmSR, are duplicated. Single cell analyses showed that duplication of the 208.6 kb region is sufficient to activate BfmSR in 75% of bacteria during planktonic (BfmSR 'OFF') growth conditions. Together, our data indicate that the combination of deterministic two-component signal transduction and stochastic, duplication-mediated activation of that TCS form a bet-hedging strategy that allows BtE264 to survive when conditions shift rapidly from those favoring planktonic growth to those requiring biofilm formation, such as may be encountered in the soils of Southeast Asia and Northern Australia. Our data highlight the positive impact that transposable elements can have on the evolution of bacterial populations.},
}
RevDate: 2025-05-20
CmpDate: 2025-05-20
Comparison of the effectiveness of different ırrigation activation methods on biofilm removal in lateral canals - an ın vitro study.
Acta odontologica Scandinavica, 84:266-274.
OBJECTIVES: Activation of sodium hypochlorite (NaOCl) to remove biofilm from lateral canal is important for the success of endodontic treatment. This study aimed to compare the biofilm dissolving capacity of different irrigation techniques in resin blocks with two lateral canals manufactured with 3D printers. Materials and methods: Biofilm-mimicking hydrogel was placed in the upper and lower lateral canals of 75 resin blocks. Main canals of the blocks were irrigated with 5% NaOCl. Then, the blocks were randomly divided into five groups: sonic activation (SA), passive ultrasonic irrigation (PUI), intracanal heating (ICH), self-adjusting file (SAF) and control. The amount of hydrogel removed was measured by weighing the blocks before and after the treatment and further visually scored. Data were analyzed using Kruskall Wallis H, Wilcoxon, Tukey Post-hoc HSD (Honestly Significant Difference) and one-way ANOVA tests.
RESULTS: The SAF group showed the highest hydrogel scores compared to other groups (p < 0.05). The hydrogel dissolution capacity of the SA group was lower compared to SAF, PUI and ICH techniques (p < 0.05). Based on visual scoring, SAF group was superior to other activation methods (p < 0.05) which are similar to each other (p > 0.05) in both upper and lower lateral canals. Conclusion: All activation methods were superior than the control group. The SAF system demonstrated superior hydrogel dissolving ability, while SA, PUI, and ICH groups showed similar effectiveness.
Additional Links: PMID-40391985
Publisher:
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40391985,
year = {2025},
author = {Aydın, U and Turan, B and Çulha, E and Baştürk Özer, MN and Özdemir, M},
title = {Comparison of the effectiveness of different ırrigation activation methods on biofilm removal in lateral canals - an ın vitro study.},
journal = {Acta odontologica Scandinavica},
volume = {84},
number = {},
pages = {266-274},
doi = {10.2340/aos.v84.43737},
pmid = {40391985},
issn = {1502-3850},
mesh = {*Biofilms/drug effects ; *Sodium Hypochlorite/pharmacology ; *Dental Pulp Cavity/microbiology ; *Root Canal Preparation/methods ; In Vitro Techniques ; Humans ; *Root Canal Irrigants/pharmacology ; },
abstract = {OBJECTIVES: Activation of sodium hypochlorite (NaOCl) to remove biofilm from lateral canal is important for the success of endodontic treatment. This study aimed to compare the biofilm dissolving capacity of different irrigation techniques in resin blocks with two lateral canals manufactured with 3D printers. Materials and methods: Biofilm-mimicking hydrogel was placed in the upper and lower lateral canals of 75 resin blocks. Main canals of the blocks were irrigated with 5% NaOCl. Then, the blocks were randomly divided into five groups: sonic activation (SA), passive ultrasonic irrigation (PUI), intracanal heating (ICH), self-adjusting file (SAF) and control. The amount of hydrogel removed was measured by weighing the blocks before and after the treatment and further visually scored. Data were analyzed using Kruskall Wallis H, Wilcoxon, Tukey Post-hoc HSD (Honestly Significant Difference) and one-way ANOVA tests.
RESULTS: The SAF group showed the highest hydrogel scores compared to other groups (p < 0.05). The hydrogel dissolution capacity of the SA group was lower compared to SAF, PUI and ICH techniques (p < 0.05). Based on visual scoring, SAF group was superior to other activation methods (p < 0.05) which are similar to each other (p > 0.05) in both upper and lower lateral canals. Conclusion: All activation methods were superior than the control group. The SAF system demonstrated superior hydrogel dissolving ability, while SA, PUI, and ICH groups showed similar effectiveness.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
*Biofilms/drug effects
*Sodium Hypochlorite/pharmacology
*Dental Pulp Cavity/microbiology
*Root Canal Preparation/methods
In Vitro Techniques
Humans
*Root Canal Irrigants/pharmacology
RevDate: 2025-05-19
Isolation and synthesis of a new cyclic tetrapeptide from marine-associated Bacillus sp. and its bacterial biofilm formation inhibitory activity.
The Journal of antibiotics [Epub ahead of print].
A new cyclic tetrapeptide named Cereusitin B (1), along with a number of known cyclic dipeptides was isolated from the fermentation broth of a marine-associated Bacillus sp. I-2. The structure of Cereusitin B, cyclo-(L-phenylalanyl-trans-4-hydroxy-L-prolyl-L-leucyl-L-alanine), was determined through extensive analysis using high-resolution electrospray ionization mass spectrometry and NMR spectral data (1D, 2D NMR), and its identity was further confirmed by Marfey' method and chemical synthesis. The antimicrobial activity tests showed that compound 2 was moderately active against Candida albicans with a MIC value of 125 µg mL[-1], while the other compounds exhibited no antimicrobial activity at the experimental concentrations. In addition, compound 1 showed the ability to inhibit the formation of S. aureus biofilm.
Additional Links: PMID-40389716
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40389716,
year = {2025},
author = {Ma, S and Li, S and Song, L and Riaz, A and Huang, R and Zhou, S and Qiu, J and Chu, Z and He, J},
title = {Isolation and synthesis of a new cyclic tetrapeptide from marine-associated Bacillus sp. and its bacterial biofilm formation inhibitory activity.},
journal = {The Journal of antibiotics},
volume = {},
number = {},
pages = {},
pmid = {40389716},
issn = {1881-1469},
support = {81773556//National Natural Science Foundation of China (National Science Foundation of China)/ ; B1040903//Southern Medical University (SMU)/ ; 2022A1515010182//Guangdong Science and Technology Department (Science and Technology Department, Guangdong Province)/ ; 2023A1515012933//Guangdong Science and Technology Department (Science and Technology Department, Guangdong Province)/ ; },
abstract = {A new cyclic tetrapeptide named Cereusitin B (1), along with a number of known cyclic dipeptides was isolated from the fermentation broth of a marine-associated Bacillus sp. I-2. The structure of Cereusitin B, cyclo-(L-phenylalanyl-trans-4-hydroxy-L-prolyl-L-leucyl-L-alanine), was determined through extensive analysis using high-resolution electrospray ionization mass spectrometry and NMR spectral data (1D, 2D NMR), and its identity was further confirmed by Marfey' method and chemical synthesis. The antimicrobial activity tests showed that compound 2 was moderately active against Candida albicans with a MIC value of 125 µg mL[-1], while the other compounds exhibited no antimicrobial activity at the experimental concentrations. In addition, compound 1 showed the ability to inhibit the formation of S. aureus biofilm.},
}
RevDate: 2025-05-21
CmpDate: 2025-05-19
A Scoping Review to Identify Clinical Signs, Symptoms and Biomarkers Reported in the Literature to Be Indicative of Biofilm in Chronic Wounds.
International wound journal, 22(5):e70181.
The objective of this review was to identify clinical signs/symptoms reported in the literature to be indicative of biofilm in chronic wounds. The Preferred Reporting Items for Systematic Reviews and Meta-Analysis extension for Scoping Reviews, and the Joanna Briggs Institute Evidence Synthesis manual guided review conduct. Any article/study type reporting signs/symptoms of biofilm in adults with venous, diabetic, pressure and/or mixed arterial/venous ulcers was eligible. Medline, Embase, CINAHL, Cochrane CENTRAL and the Bielefeld Academic Search Engine were searched. Titles/abstracts and full-text articles were screened against eligibility criteria. One-hundred and eleven reports of 109 articles were included. They provided 830 accounts of clinical signs/ symptoms being indicative of biofilm. These were categorised into 26 statements. Visual indicators such as a shiny, slimy layer on a non-healing wound surface quickly reforming in the absence of frequent cleansing or debridement represented 24% of accounts, followed by failed response to antimicrobial therapies (15%), and failure of wound to close or progress to healing despite optimal management strategies (13%). Wound duration > 6 weeks and extreme tolerance to host defences represented 1% of accounts. Clinical signs/symptoms are recommended and used as indicators of biofilm presence in chronic wounds but with little supporting validation data.
Additional Links: PMID-40389698
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40389698,
year = {2025},
author = {Ivory, JD and Perrier, L and Vellinga, A and Sezgin, D and Hobbs, CM and Ffrench, C and Coutts, PM and O'Gara, JP and Gethin, G},
title = {A Scoping Review to Identify Clinical Signs, Symptoms and Biomarkers Reported in the Literature to Be Indicative of Biofilm in Chronic Wounds.},
journal = {International wound journal},
volume = {22},
number = {5},
pages = {e70181},
pmid = {40389698},
issn = {1742-481X},
support = {GOIPG/2020/535//Irish Research Council/ ; CDA-2019-007//Health Research Board (HRB) Collaborative Doctoral Awards (CDA) Diabetic Foot Disease: from Prevention to Improved patient Outcones (DFD PRIMO)/ ; },
mesh = {Humans ; *Biofilms ; *Wound Healing/physiology ; Chronic Disease ; *Wound Infection/diagnosis/microbiology ; Biomarkers ; Male ; Female ; Adult ; Middle Aged ; Aged ; },
abstract = {The objective of this review was to identify clinical signs/symptoms reported in the literature to be indicative of biofilm in chronic wounds. The Preferred Reporting Items for Systematic Reviews and Meta-Analysis extension for Scoping Reviews, and the Joanna Briggs Institute Evidence Synthesis manual guided review conduct. Any article/study type reporting signs/symptoms of biofilm in adults with venous, diabetic, pressure and/or mixed arterial/venous ulcers was eligible. Medline, Embase, CINAHL, Cochrane CENTRAL and the Bielefeld Academic Search Engine were searched. Titles/abstracts and full-text articles were screened against eligibility criteria. One-hundred and eleven reports of 109 articles were included. They provided 830 accounts of clinical signs/ symptoms being indicative of biofilm. These were categorised into 26 statements. Visual indicators such as a shiny, slimy layer on a non-healing wound surface quickly reforming in the absence of frequent cleansing or debridement represented 24% of accounts, followed by failed response to antimicrobial therapies (15%), and failure of wound to close or progress to healing despite optimal management strategies (13%). Wound duration > 6 weeks and extreme tolerance to host defences represented 1% of accounts. Clinical signs/symptoms are recommended and used as indicators of biofilm presence in chronic wounds but with little supporting validation data.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
Humans
*Biofilms
*Wound Healing/physiology
Chronic Disease
*Wound Infection/diagnosis/microbiology
Biomarkers
Male
Female
Adult
Middle Aged
Aged
RevDate: 2025-05-19
Induction heating combined with antibiotics or SAAP-148 effectively reduces biofilm-embedded Staphylococcus aureus on a fracture-related implant mimic.
Bone & joint research, 14(5):485-494.
AIMS: Fracture-related infections and the associated treatment failure burden our society and healthcare system significantly. As an alternative approach, we investigated the effect of non-contact induction heating (NCIH) against Staphylococcus aureus within mature biofilms. In addition, we assessed the ability of antibiotics, the antimicrobial peptide SAAP-148, and bacteriophage (phage) ISP to enhance the efficacy of NCIH, thereby allowing the use of lower temperatures during NCIH.
METHODS: Clinical isolates of methicillin-resistant and methicillin-sensitive S. aureus (methicillin-resistant S. aureus (MRSA), methicillin-sensitive S. aureus (MSSA)) were cultured for seven days on Ti-6Al-7Nb (mimicking fracture plates) discs to obtain mature biofilms. Biofilms were exposed to 60°C to 80°C NCIH. In addition, biofilms were sequentially exposed to 60°C to 70°C NCIH and rifampicin/ciprofloxacin, SAAP-148, or phage ISP. Biofilm-embedded bacteria were harvested by sonication to determine the bacterial load and visualized by confocal microscopy (LIVE/DEAD).
RESULTS: NCIH to 60°C, 70°C, and 80°C reduced biofilm-embedded MRSA and MSSA by 2.3-log, 4.9-log, 5.5-log, and 1.1-log, 3.4-log, and 6.6-log CFU/ml, respectively. LIVE/DEAD staining revealed NCIH-induced bacterial cell death throughout the biofilm layers. The sequential combination of rifampicin/ciprofloxacin at 10 µg/ml and 1,280 µg/ml (MRSA) or 156 µg/l and 64 µg/ml (MSSA) and 70°C NCIH synergistically reduced biofilm-embedded bacteria by 2.7-log and 3.7-log CFU/ml, respectively, while the alternating exposure order reduced bacterial counts by -0.1 and 1.7-log CFU/ml. SAAP-148 at 51.2 µM followed by 70°C NCIH further diminished biofilm-embedded MRSA and MSSA by 2.3-log and 1.5-log CFU/ml, respectively. No significant reductions were observed for NCIH combined with phage ISP compared to these treatments alone.
CONCLUSION: NCIH effectively reduced biofilm-embedded S. aureus on Ti-6Al-7Nb in a heat-dependent fashion. Rifampicin/ciprofloxacin and SAAP-148, but not phage ISP, enhanced the efficacy of NCIH. Antibiotic exposure at suboptimal concentrations followed by NCIH was more effective than vice versa, suggesting that the application of this approach might be most suitable in clinical situations where antibiotic treatment has already started.
Additional Links: PMID-40389237
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40389237,
year = {2025},
author = {Verheul, M and Wagenmakers, AA and Nelissen, RGHH and Nibbering, PH and Pijls, BG},
title = {Induction heating combined with antibiotics or SAAP-148 effectively reduces biofilm-embedded Staphylococcus aureus on a fracture-related implant mimic.},
journal = {Bone & joint research},
volume = {14},
number = {5},
pages = {485-494},
pmid = {40389237},
issn = {2046-3758},
support = {/NWO_/Dutch Research Council/Netherlands ; },
abstract = {AIMS: Fracture-related infections and the associated treatment failure burden our society and healthcare system significantly. As an alternative approach, we investigated the effect of non-contact induction heating (NCIH) against Staphylococcus aureus within mature biofilms. In addition, we assessed the ability of antibiotics, the antimicrobial peptide SAAP-148, and bacteriophage (phage) ISP to enhance the efficacy of NCIH, thereby allowing the use of lower temperatures during NCIH.
METHODS: Clinical isolates of methicillin-resistant and methicillin-sensitive S. aureus (methicillin-resistant S. aureus (MRSA), methicillin-sensitive S. aureus (MSSA)) were cultured for seven days on Ti-6Al-7Nb (mimicking fracture plates) discs to obtain mature biofilms. Biofilms were exposed to 60°C to 80°C NCIH. In addition, biofilms were sequentially exposed to 60°C to 70°C NCIH and rifampicin/ciprofloxacin, SAAP-148, or phage ISP. Biofilm-embedded bacteria were harvested by sonication to determine the bacterial load and visualized by confocal microscopy (LIVE/DEAD).
RESULTS: NCIH to 60°C, 70°C, and 80°C reduced biofilm-embedded MRSA and MSSA by 2.3-log, 4.9-log, 5.5-log, and 1.1-log, 3.4-log, and 6.6-log CFU/ml, respectively. LIVE/DEAD staining revealed NCIH-induced bacterial cell death throughout the biofilm layers. The sequential combination of rifampicin/ciprofloxacin at 10 µg/ml and 1,280 µg/ml (MRSA) or 156 µg/l and 64 µg/ml (MSSA) and 70°C NCIH synergistically reduced biofilm-embedded bacteria by 2.7-log and 3.7-log CFU/ml, respectively, while the alternating exposure order reduced bacterial counts by -0.1 and 1.7-log CFU/ml. SAAP-148 at 51.2 µM followed by 70°C NCIH further diminished biofilm-embedded MRSA and MSSA by 2.3-log and 1.5-log CFU/ml, respectively. No significant reductions were observed for NCIH combined with phage ISP compared to these treatments alone.
CONCLUSION: NCIH effectively reduced biofilm-embedded S. aureus on Ti-6Al-7Nb in a heat-dependent fashion. Rifampicin/ciprofloxacin and SAAP-148, but not phage ISP, enhanced the efficacy of NCIH. Antibiotic exposure at suboptimal concentrations followed by NCIH was more effective than vice versa, suggesting that the application of this approach might be most suitable in clinical situations where antibiotic treatment has already started.},
}
RevDate: 2025-05-19
Sweeteners affect biofilm formation and virulence gene expression in Pseudomonas aeruginosa PAO1.
Biofouling [Epub ahead of print].
Pseudomonas aeruginosa is an opportunistic pathogen able to form biofilms, contributing to its virulence. With the increasing use of sweeteners in various foods, understanding their influence on bacterial behavior is critical. This study investigated the virulence of P. aeruginosa PAO1 exposed to sweeteners (erythritol, stevia, fructose, coconut sugar, cane sugar, demerara). Sweeteners didn't affect growth rates. Erythritol stimulated biofilm (100 µg/mL, 159.98% formation), while 10 µg/mL of coconut sugar, cane sugar, and demerara promoted lower levels (∼70% formation). Erythritol stimulated exopolysaccharides production but reduced biofilm eDNA. Stevia, fructose, and coconut sugar increased the expression of lasI, lasR, rhlI, rhlR, pqsA, mvfR, and pvdF. HPLC analysis confirmed sucrose as the major sugar in demerara, coconut and cane sugar. Erythritol stimulated biofilm and some virulence genes expression, while other sweeteners' effects varied. Cane sugar was a biofilm inhibitor with a limited gene expression effect. The sweeteners' impact on microorganisms is diverse and should be further investigated.
Additional Links: PMID-40387139
Publisher:
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40387139,
year = {2025},
author = {Carević Milićević, T and Novović, K and Nikolić, B and Stojković, D and Maksimović, V and Milosavljević, D and Ivanov, M},
title = {Sweeteners affect biofilm formation and virulence gene expression in Pseudomonas aeruginosa PAO1.},
journal = {Biofouling},
volume = {},
number = {},
pages = {1-11},
doi = {10.1080/08927014.2025.2504023},
pmid = {40387139},
issn = {1029-2454},
abstract = {Pseudomonas aeruginosa is an opportunistic pathogen able to form biofilms, contributing to its virulence. With the increasing use of sweeteners in various foods, understanding their influence on bacterial behavior is critical. This study investigated the virulence of P. aeruginosa PAO1 exposed to sweeteners (erythritol, stevia, fructose, coconut sugar, cane sugar, demerara). Sweeteners didn't affect growth rates. Erythritol stimulated biofilm (100 µg/mL, 159.98% formation), while 10 µg/mL of coconut sugar, cane sugar, and demerara promoted lower levels (∼70% formation). Erythritol stimulated exopolysaccharides production but reduced biofilm eDNA. Stevia, fructose, and coconut sugar increased the expression of lasI, lasR, rhlI, rhlR, pqsA, mvfR, and pvdF. HPLC analysis confirmed sucrose as the major sugar in demerara, coconut and cane sugar. Erythritol stimulated biofilm and some virulence genes expression, while other sweeteners' effects varied. Cane sugar was a biofilm inhibitor with a limited gene expression effect. The sweeteners' impact on microorganisms is diverse and should be further investigated.},
}
RevDate: 2025-05-19
Magnetically Tunable Hydrogel for Biofilm Control.
ACS applied bio materials [Epub ahead of print].
Bacterial biofilm formation contributes to healthcare and energy challenges, and researchers are actively pursuing a range of strategies to restrict the spread of biofilms in an eco-friendly manner. Commonly used approaches in industry rely on physical removal and chemical techniques, frequently targeting mature biofilms. While effective, these methods often face implementation challenges in remote settings and can have off-target environmental impacts. As a result, an alternative strategy is to focus on controlling or limiting the biofilm formation and growth rates with remote stimuli. It has been shown that the mechanotransduction pathway intrinsic to bacteria responds to changes in the storage modulus of the growth surface, modifying the bacteria's motility and biofilm formation. We developed a material with magnetically tunable mechanical properties by intercalating magnetic nanoparticles into an agar gel matrix and investigated its ability to control Escherichia coli motility and biofilm growth. The initial storage modulus ranges from 0.5 to 2.5 kPa, depending on the material composition. Upon exposure to a 20 mT magnetic field using standard neodymium magnets, the modulus is dynamically and reversibly increased by approximately 30%. As a result of this increase, the expansion rate of the E. coli biofilm is reduced by approximately 40%. The simplicity of the manipulation of its mechanical property not only gives this biomaterial potential to further mechanosensing mechanism research but also proves to be an innovative strategy for remote and eco-conscious restriction of biofilm formation.
Additional Links: PMID-40383927
Publisher:
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40383927,
year = {2025},
author = {Sun, R and Gangan, MS and Wang, Q and Boedicker, JQ and Armani, AM},
title = {Magnetically Tunable Hydrogel for Biofilm Control.},
journal = {ACS applied bio materials},
volume = {},
number = {},
pages = {},
doi = {10.1021/acsabm.5c00409},
pmid = {40383927},
issn = {2576-6422},
abstract = {Bacterial biofilm formation contributes to healthcare and energy challenges, and researchers are actively pursuing a range of strategies to restrict the spread of biofilms in an eco-friendly manner. Commonly used approaches in industry rely on physical removal and chemical techniques, frequently targeting mature biofilms. While effective, these methods often face implementation challenges in remote settings and can have off-target environmental impacts. As a result, an alternative strategy is to focus on controlling or limiting the biofilm formation and growth rates with remote stimuli. It has been shown that the mechanotransduction pathway intrinsic to bacteria responds to changes in the storage modulus of the growth surface, modifying the bacteria's motility and biofilm formation. We developed a material with magnetically tunable mechanical properties by intercalating magnetic nanoparticles into an agar gel matrix and investigated its ability to control Escherichia coli motility and biofilm growth. The initial storage modulus ranges from 0.5 to 2.5 kPa, depending on the material composition. Upon exposure to a 20 mT magnetic field using standard neodymium magnets, the modulus is dynamically and reversibly increased by approximately 30%. As a result of this increase, the expansion rate of the E. coli biofilm is reduced by approximately 40%. The simplicity of the manipulation of its mechanical property not only gives this biomaterial potential to further mechanosensing mechanism research but also proves to be an innovative strategy for remote and eco-conscious restriction of biofilm formation.},
}
RevDate: 2025-05-18
Design, synthesis and evaluation of quinolone quaternary ammonium antibacterial agent with killing ability to biofilm.
Bioorganic chemistry, 162:108579 pii:S0045-2068(25)00459-6 [Epub ahead of print].
Staphylococcus aureus (S. aureus) is the most common and widely distributed pathogenic bacterium. The problem of methicillin-resistant Staphylococcus aureus (MRSA) caused by the widespread use of antibiotics is particularly severe. In addition, S. aureus can resist antibiotics by forming biofilms, making clinical treatment difficult. A series of antimicrobial quinolone-based quaternary ammonium compounds were designed and synthesized. Among them, the optimal compound 3e showed the strongest activity against S. aureus, and it had relatively low hemolytic toxicity and cytotoxicity. Compound 3e has excellent bactericidal performance, capable of quickly and thoroughly sterilizing. In continuous sub-lethal concentration bacterial passage culture, no bacterial resistance tendency caused by 3e was found. Moreover, 3e can exert a significant level of activity in blood components and still has a period of suppression on bacteria after the drug is removed. Encouragingly, 3e has a certain bactericidal potential against bacteria with high concentration and high tolerance. It has shown strong bactericidal effects when fighting against persister bacteria and biofilms in vitro. Mechanism research indicates that 3e exerts its antimicrobial action through related membrane activity and is related to membrane components phosphatidylglycerol (PG) and cardiolipin (CL). In addition, 3e can also bind to bacterial DNA.
Additional Links: PMID-40383012
Publisher:
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40383012,
year = {2025},
author = {Gao, C and Li, R and Li, Y and Wu, Y and Qu, Y and Ampomah-Wireko, M and Zheng, J and Wang, Z and Wang, YN and Zhang, E},
title = {Design, synthesis and evaluation of quinolone quaternary ammonium antibacterial agent with killing ability to biofilm.},
journal = {Bioorganic chemistry},
volume = {162},
number = {},
pages = {108579},
doi = {10.1016/j.bioorg.2025.108579},
pmid = {40383012},
issn = {1090-2120},
abstract = {Staphylococcus aureus (S. aureus) is the most common and widely distributed pathogenic bacterium. The problem of methicillin-resistant Staphylococcus aureus (MRSA) caused by the widespread use of antibiotics is particularly severe. In addition, S. aureus can resist antibiotics by forming biofilms, making clinical treatment difficult. A series of antimicrobial quinolone-based quaternary ammonium compounds were designed and synthesized. Among them, the optimal compound 3e showed the strongest activity against S. aureus, and it had relatively low hemolytic toxicity and cytotoxicity. Compound 3e has excellent bactericidal performance, capable of quickly and thoroughly sterilizing. In continuous sub-lethal concentration bacterial passage culture, no bacterial resistance tendency caused by 3e was found. Moreover, 3e can exert a significant level of activity in blood components and still has a period of suppression on bacteria after the drug is removed. Encouragingly, 3e has a certain bactericidal potential against bacteria with high concentration and high tolerance. It has shown strong bactericidal effects when fighting against persister bacteria and biofilms in vitro. Mechanism research indicates that 3e exerts its antimicrobial action through related membrane activity and is related to membrane components phosphatidylglycerol (PG) and cardiolipin (CL). In addition, 3e can also bind to bacterial DNA.},
}
RevDate: 2025-05-17
CmpDate: 2025-05-17
Contribution of icaADBC genes in biofilm production ability of Staphylococcus aureus clinical isolates collected from hospitalized patients at a burn center in North of Iran.
BMC microbiology, 25(1):302.
INTRODUCTION: The pathogenicity of Staphylococcus aureus is significantly attributed to its capacity to produce biofilms, which bolster bacterial resistance against antibiotics and host immune responses. This study aimed to explore the involvement of icaABCD genes in biofilm formation ability of S. aureus clinical isolates.
MATERIALS AND METHODS: One hundred clinical S. aureus isolates were collected from hospitalized patients at a burn center in North of Iran. The isolates were identified using standard biochemical tests and confirmed by the presence of the nuc gene. Antibiotic susceptibility profiles were determined through the disk agar diffusion method. Biofilm formation capacity was determined using microtiter plate assay. PCR test was conducted to detect the presence of icaABCD genes.
RESULTS: Penicillin exhibited the highest resistance rate (94%), while vancomycin was most effective antibiotic with 6% resistance. Besides, 32% of the isolates demonstrated as multidrug resistant (MDR) and 29% were Methicillin-resistant S. aureus (MRSA). Notably, 89% of the isolates were identified as biofilm produces, while 54 (60.67%), 28 (31.46%), and 7 (7.86%) isolates exhibited strong, moderate, and weakly biofilm production ability, respectively. PCR results revealed a prevalence of 90%, 92%, 92%, and 94% for the icaA, icaB, icaC, and icaD genes, respectively. Intriguingly, the MDR isolates exhibited a 100% prevalence of these genes. Similarly, 96.55%, 89.65%, 89.65% and 96.55% of the MRSA isolates were carrying the icaA, icaB, icaC, and icaD genes, respectively.
CONCLUSION: This study revealed a noteworthy prevalence of biofilm-producing strains of S. aureus. High prevalence of icaADBC genes as well as highlighted capacity of the biofilm formation in MRSA and MDR strains exhibited a potential correlation between biofilm and antibiotic resistance patterns. Given the enhanced resilience of bacteria within biofilms against antibiotics, addressing biofilm production is imperative alongside antibiotic treatments for effective control and eradication of infections.
Additional Links: PMID-40382552
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40382552,
year = {2025},
author = {Alibegli, M and Bay, A and Fazelnejad, A and Ghezelghaye, PN and Soghondikolaei, HJ and Goli, HR},
title = {Contribution of icaADBC genes in biofilm production ability of Staphylococcus aureus clinical isolates collected from hospitalized patients at a burn center in North of Iran.},
journal = {BMC microbiology},
volume = {25},
number = {1},
pages = {302},
pmid = {40382552},
issn = {1471-2180},
support = {1466//Mazandaran University of Medical Sciences/ ; },
mesh = {*Biofilms/growth & development ; Humans ; Iran ; *Staphylococcus aureus/genetics/drug effects/isolation & purification/physiology ; *Staphylococcal Infections/microbiology ; Anti-Bacterial Agents/pharmacology ; *Bacterial Proteins/genetics ; Microbial Sensitivity Tests ; Burn Units ; Drug Resistance, Multiple, Bacterial/genetics ; Methicillin-Resistant Staphylococcus aureus/genetics/drug effects/isolation & purification ; Genes, Bacterial ; Male ; Burns/microbiology ; },
abstract = {INTRODUCTION: The pathogenicity of Staphylococcus aureus is significantly attributed to its capacity to produce biofilms, which bolster bacterial resistance against antibiotics and host immune responses. This study aimed to explore the involvement of icaABCD genes in biofilm formation ability of S. aureus clinical isolates.
MATERIALS AND METHODS: One hundred clinical S. aureus isolates were collected from hospitalized patients at a burn center in North of Iran. The isolates were identified using standard biochemical tests and confirmed by the presence of the nuc gene. Antibiotic susceptibility profiles were determined through the disk agar diffusion method. Biofilm formation capacity was determined using microtiter plate assay. PCR test was conducted to detect the presence of icaABCD genes.
RESULTS: Penicillin exhibited the highest resistance rate (94%), while vancomycin was most effective antibiotic with 6% resistance. Besides, 32% of the isolates demonstrated as multidrug resistant (MDR) and 29% were Methicillin-resistant S. aureus (MRSA). Notably, 89% of the isolates were identified as biofilm produces, while 54 (60.67%), 28 (31.46%), and 7 (7.86%) isolates exhibited strong, moderate, and weakly biofilm production ability, respectively. PCR results revealed a prevalence of 90%, 92%, 92%, and 94% for the icaA, icaB, icaC, and icaD genes, respectively. Intriguingly, the MDR isolates exhibited a 100% prevalence of these genes. Similarly, 96.55%, 89.65%, 89.65% and 96.55% of the MRSA isolates were carrying the icaA, icaB, icaC, and icaD genes, respectively.
CONCLUSION: This study revealed a noteworthy prevalence of biofilm-producing strains of S. aureus. High prevalence of icaADBC genes as well as highlighted capacity of the biofilm formation in MRSA and MDR strains exhibited a potential correlation between biofilm and antibiotic resistance patterns. Given the enhanced resilience of bacteria within biofilms against antibiotics, addressing biofilm production is imperative alongside antibiotic treatments for effective control and eradication of infections.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
*Biofilms/growth & development
Humans
Iran
*Staphylococcus aureus/genetics/drug effects/isolation & purification/physiology
*Staphylococcal Infections/microbiology
Anti-Bacterial Agents/pharmacology
*Bacterial Proteins/genetics
Microbial Sensitivity Tests
Burn Units
Drug Resistance, Multiple, Bacterial/genetics
Methicillin-Resistant Staphylococcus aureus/genetics/drug effects/isolation & purification
Genes, Bacterial
Male
Burns/microbiology
RevDate: 2025-05-17
CmpDate: 2025-05-17
Natural antimicrobials synergistically coupled with nanomotors: An innovative strategy for biofilm eradication.
Food research international (Ottawa, Ont.), 212:116510.
Biofilms are one of the most important problems occurring in industrial environments, especially in food industry. The possibility of foodborne disease outbreaks as a result of biofilm-food cross-contamination is a distinct concern, along with the substantial costs associated with food spoilage and biofilm control. Besides, despite daily cleaning and disinfection, many bacteria grow in machines and surfaces in food processing plants, some of them forming biofilms. A promising procedure for disinfection and biofilm elimination could be the use of hybrid antimicrobial nanomaterials endowed with motion (i.e., nanomotors). Herein, we report Janus nanoparticles based on the conjunction of platinum and mesoporous silica nanoparticles, functionalized with a derivative of a natural antimicrobial compound, vanillin. The engineered nanomotors combine H2O2-triggered self-propulsion with the antimicrobial activity of vanillin, allowing enhanced physical penetration into the 3D matrix formed by the exopolymeric substances generated in monospecies (Staphylococcus aureus) and multispecies (S. aureus and Escherichia coli) biofilms and the subsequent elimination of pathogenic cells.
Additional Links: PMID-40382078
Publisher:
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40382078,
year = {2025},
author = {Medaglia, S and Escudero, A and Morellá-Aucejo, Á and Hicke, FJ and Reyes-Torres, M and Marin-Ferrandis, L and Amorós, P and Marcos, MD and Bernardos, A and Díez, P and Martínez-Máñez, R},
title = {Natural antimicrobials synergistically coupled with nanomotors: An innovative strategy for biofilm eradication.},
journal = {Food research international (Ottawa, Ont.)},
volume = {212},
number = {},
pages = {116510},
doi = {10.1016/j.foodres.2025.116510},
pmid = {40382078},
issn = {1873-7145},
mesh = {*Biofilms/drug effects/growth & development ; *Benzaldehydes/pharmacology/chemistry ; Staphylococcus aureus/drug effects ; Escherichia coli/drug effects ; Silicon Dioxide/chemistry ; Hydrogen Peroxide/chemistry ; Platinum/chemistry ; *Anti-Infective Agents/pharmacology ; *Anti-Bacterial Agents/pharmacology ; *Nanoparticles/chemistry ; Food Microbiology ; },
abstract = {Biofilms are one of the most important problems occurring in industrial environments, especially in food industry. The possibility of foodborne disease outbreaks as a result of biofilm-food cross-contamination is a distinct concern, along with the substantial costs associated with food spoilage and biofilm control. Besides, despite daily cleaning and disinfection, many bacteria grow in machines and surfaces in food processing plants, some of them forming biofilms. A promising procedure for disinfection and biofilm elimination could be the use of hybrid antimicrobial nanomaterials endowed with motion (i.e., nanomotors). Herein, we report Janus nanoparticles based on the conjunction of platinum and mesoporous silica nanoparticles, functionalized with a derivative of a natural antimicrobial compound, vanillin. The engineered nanomotors combine H2O2-triggered self-propulsion with the antimicrobial activity of vanillin, allowing enhanced physical penetration into the 3D matrix formed by the exopolymeric substances generated in monospecies (Staphylococcus aureus) and multispecies (S. aureus and Escherichia coli) biofilms and the subsequent elimination of pathogenic cells.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
*Biofilms/drug effects/growth & development
*Benzaldehydes/pharmacology/chemistry
Staphylococcus aureus/drug effects
Escherichia coli/drug effects
Silicon Dioxide/chemistry
Hydrogen Peroxide/chemistry
Platinum/chemistry
*Anti-Infective Agents/pharmacology
*Anti-Bacterial Agents/pharmacology
*Nanoparticles/chemistry
Food Microbiology
RevDate: 2025-05-17
CmpDate: 2025-05-17
Optical interferometric: A novel approach for sensitive cost-effective measurement of multispecies biofilm from stress-tolerant field samples.
Food research international (Ottawa, Ont.), 212:116378.
Biofilms significantly impact public health and food safety within the meat industry. Detecting and quantifying biofilms are crucial tasks; however, their inherent complexity and heterogeneity, particularly in immature stages, present substantial challenges. Innovative techniques are necessary for accurate biofilm measurement, despite the presence of diverse interfering agents. An assessment of multispecies biofilms from cattle abattoir environmental samples (wall, basin, and door), equipment (tub, knives, and swivel), and offal (heart, lung, liver, spleen, rumen, and intestine). To elucidate the complexities of biofilm formation, a dual-pronged approach was employed, utilizing epifluorescence microscopy and optical interferometry to conduct a comprehensive analysis of biofilms that had developed on two distinct types of surfaces. Specifically, biotic surfaces that had undergone chilling and abiotic surfaces subjected to chlorination were examined to gain a deeper understanding of the structural and compositional characteristics of these microbial communities. Additionally, the presence of antibiotic-resistant bacteria within the submerged biofilm was evaluated. Despite chilling, the multispecies biofilm continued to grow from 0.2 μm to a maximum of 1.75 μm on the beef spleen surface, demonstrating the interplay of different bacterial species in biofilm formation on biotic surfaces. The highest antibacterial resistance was recorded for Staphylococcus simulans, followed by Staphylococcus saprophyticus and Staphylococcus aureus. In conclusion, the optical interferometer is a straightforward, fast, and sensitive technique for measuring biofilm thickness within the range of 0.1 to 4 μm. Progress in this field can revolutionize food safety, hygiene, biosecurity, and biomedical applications.
Additional Links: PMID-40382065
Publisher:
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40382065,
year = {2025},
author = {Zaki, RS and Abdelhaseib, M and Mahmoud, MMA},
title = {Optical interferometric: A novel approach for sensitive cost-effective measurement of multispecies biofilm from stress-tolerant field samples.},
journal = {Food research international (Ottawa, Ont.)},
volume = {212},
number = {},
pages = {116378},
doi = {10.1016/j.foodres.2025.116378},
pmid = {40382065},
issn = {1873-7145},
mesh = {*Biofilms/growth & development ; Animals ; Cattle ; *Interferometry/methods/economics ; *Food Microbiology/methods ; Microscopy, Fluorescence ; Cost-Benefit Analysis ; Bacteria/growth & development ; },
abstract = {Biofilms significantly impact public health and food safety within the meat industry. Detecting and quantifying biofilms are crucial tasks; however, their inherent complexity and heterogeneity, particularly in immature stages, present substantial challenges. Innovative techniques are necessary for accurate biofilm measurement, despite the presence of diverse interfering agents. An assessment of multispecies biofilms from cattle abattoir environmental samples (wall, basin, and door), equipment (tub, knives, and swivel), and offal (heart, lung, liver, spleen, rumen, and intestine). To elucidate the complexities of biofilm formation, a dual-pronged approach was employed, utilizing epifluorescence microscopy and optical interferometry to conduct a comprehensive analysis of biofilms that had developed on two distinct types of surfaces. Specifically, biotic surfaces that had undergone chilling and abiotic surfaces subjected to chlorination were examined to gain a deeper understanding of the structural and compositional characteristics of these microbial communities. Additionally, the presence of antibiotic-resistant bacteria within the submerged biofilm was evaluated. Despite chilling, the multispecies biofilm continued to grow from 0.2 μm to a maximum of 1.75 μm on the beef spleen surface, demonstrating the interplay of different bacterial species in biofilm formation on biotic surfaces. The highest antibacterial resistance was recorded for Staphylococcus simulans, followed by Staphylococcus saprophyticus and Staphylococcus aureus. In conclusion, the optical interferometer is a straightforward, fast, and sensitive technique for measuring biofilm thickness within the range of 0.1 to 4 μm. Progress in this field can revolutionize food safety, hygiene, biosecurity, and biomedical applications.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
*Biofilms/growth & development
Animals
Cattle
*Interferometry/methods/economics
*Food Microbiology/methods
Microscopy, Fluorescence
Cost-Benefit Analysis
Bacteria/growth & development
RevDate: 2025-05-17
CmpDate: 2025-05-17
Kinetic behaviour of petroleum based oily wastewater treatment in a hybrid moving bed biofilm reactor.
Biodegradation, 36(3):44.
Performance of a laboratory scale moving bed hybrid bioreactor (MBHBR) was assessed in the present study under batch operation with varying concentration of oil and grease in wastewater sample in the range of 62-370 mg/L. Oily wastewater was fed in the MBHBR with polypropylene carriers in the temperature range of 18.5-25.7 °C and the pH range of 7.28-8.24. The study showed a maximum oil removal of 85.4% for an initial oil concentration of 275 mg/L under a contact time of 20 h. Monod's kinetic theory has been applied to the results as obtained in the batch experimental study considering the contribution of both suspended and attached biomass. Various kinetic parameters were estimated as Maximum specific substrate utilisation rate, k = 0.32/d, Half saturation constant, Ks = 209 mg/L, Yield coefficient, Y = 0.728 mg/mg and Endogenous decay constant, kd = 0.016/d. No major inhibition was observed during treatment of synthetic oily wastewater for the concentration range of 62-275 mg/L. The removal efficiency of oil was observed to be better in presence of attached biomass than suspended growth environment. The present study will be useful for the design of hybrid bio-reactors and for development of mathematical models under similar experimental condition.
Additional Links: PMID-40381047
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40381047,
year = {2025},
author = {Sanghamitra, P and Mazumder, D and Mukherjee, S},
title = {Kinetic behaviour of petroleum based oily wastewater treatment in a hybrid moving bed biofilm reactor.},
journal = {Biodegradation},
volume = {36},
number = {3},
pages = {44},
pmid = {40381047},
issn = {1572-9729},
mesh = {*Bioreactors/microbiology ; *Wastewater/chemistry/microbiology ; *Biofilms/growth & development ; Kinetics ; Biodegradation, Environmental ; *Petroleum/metabolism/analysis ; *Water Pollutants, Chemical/metabolism ; *Waste Disposal, Fluid/methods ; Biomass ; *Water Purification/methods ; },
abstract = {Performance of a laboratory scale moving bed hybrid bioreactor (MBHBR) was assessed in the present study under batch operation with varying concentration of oil and grease in wastewater sample in the range of 62-370 mg/L. Oily wastewater was fed in the MBHBR with polypropylene carriers in the temperature range of 18.5-25.7 °C and the pH range of 7.28-8.24. The study showed a maximum oil removal of 85.4% for an initial oil concentration of 275 mg/L under a contact time of 20 h. Monod's kinetic theory has been applied to the results as obtained in the batch experimental study considering the contribution of both suspended and attached biomass. Various kinetic parameters were estimated as Maximum specific substrate utilisation rate, k = 0.32/d, Half saturation constant, Ks = 209 mg/L, Yield coefficient, Y = 0.728 mg/mg and Endogenous decay constant, kd = 0.016/d. No major inhibition was observed during treatment of synthetic oily wastewater for the concentration range of 62-275 mg/L. The removal efficiency of oil was observed to be better in presence of attached biomass than suspended growth environment. The present study will be useful for the design of hybrid bio-reactors and for development of mathematical models under similar experimental condition.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
*Bioreactors/microbiology
*Wastewater/chemistry/microbiology
*Biofilms/growth & development
Kinetics
Biodegradation, Environmental
*Petroleum/metabolism/analysis
*Water Pollutants, Chemical/metabolism
*Waste Disposal, Fluid/methods
Biomass
*Water Purification/methods
RevDate: 2025-05-19
CmpDate: 2025-05-16
In vitro activity of cefiderocol against Gram-negative aerobic bacilli in planktonic and biofilm form-alone and in combination with bacteriophages.
Scientific reports, 15(1):17105.
Multi-drug resistant Gram-negative pathogens are increasingly difficult-to-treat perpetrators of infections. New, innovative, and more multifaceted therapies for the treatment of multi-drug resistant strains are thus urgent to hinder further drug resistance and mitigate deadly, untreatable infections. Our study aimed to investigate the efficacy of cefiderocol against Gram-negative aerobic bacteria alone and in combination with phages. The minimum inhibitory concentration (MIC) of cefiderocol was determined using the microdilution broth method, while the minimum biofilm bactericidal concentration was assessed using isothermal microcalorimetry. The combined effect of cefiderocol and phages was evaluated using colony-forming unit counts. Results demonstrated a notable antibacterial effect of cefiderocol, with 83.4% of tested strains exhibiting susceptibility. When combined with phages, the MIC of cefiderocol was reduced by 2-64-fold, indicating a synergistic interaction between the two agents. Furthermore, the combination therapy showed enhanced efficacy against biofilm compared to monotherapy with either cefiderocol or phages alone, leading to complete biofilm elimination in certain cases. This study highlights the potential of combining cefiderocol with phages as a strategy to combat multi-drug resistant Gram-negative bacterial infections. The observed synergy suggests that this combination therapy could improve treatment outcomes and help address the challenges of antibiotic resistance and biofilm-associated infections.
Additional Links: PMID-40379736
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40379736,
year = {2025},
author = {Pirlar, RF and Halili, N and Travnik, T and Trampuz, A and Karbysheva, S},
title = {In vitro activity of cefiderocol against Gram-negative aerobic bacilli in planktonic and biofilm form-alone and in combination with bacteriophages.},
journal = {Scientific reports},
volume = {15},
number = {1},
pages = {17105},
pmid = {40379736},
issn = {2045-2322},
mesh = {*Biofilms/drug effects/growth & development ; *Cephalosporins/pharmacology ; *Anti-Bacterial Agents/pharmacology ; Microbial Sensitivity Tests ; *Bacteriophages/physiology ; Cefiderocol/pharmacology ; *Gram-Negative Aerobic Bacteria/drug effects/virology/physiology ; Humans ; *Plankton/drug effects/virology ; Drug Resistance, Multiple, Bacterial/drug effects ; },
abstract = {Multi-drug resistant Gram-negative pathogens are increasingly difficult-to-treat perpetrators of infections. New, innovative, and more multifaceted therapies for the treatment of multi-drug resistant strains are thus urgent to hinder further drug resistance and mitigate deadly, untreatable infections. Our study aimed to investigate the efficacy of cefiderocol against Gram-negative aerobic bacteria alone and in combination with phages. The minimum inhibitory concentration (MIC) of cefiderocol was determined using the microdilution broth method, while the minimum biofilm bactericidal concentration was assessed using isothermal microcalorimetry. The combined effect of cefiderocol and phages was evaluated using colony-forming unit counts. Results demonstrated a notable antibacterial effect of cefiderocol, with 83.4% of tested strains exhibiting susceptibility. When combined with phages, the MIC of cefiderocol was reduced by 2-64-fold, indicating a synergistic interaction between the two agents. Furthermore, the combination therapy showed enhanced efficacy against biofilm compared to monotherapy with either cefiderocol or phages alone, leading to complete biofilm elimination in certain cases. This study highlights the potential of combining cefiderocol with phages as a strategy to combat multi-drug resistant Gram-negative bacterial infections. The observed synergy suggests that this combination therapy could improve treatment outcomes and help address the challenges of antibiotic resistance and biofilm-associated infections.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
*Biofilms/drug effects/growth & development
*Cephalosporins/pharmacology
*Anti-Bacterial Agents/pharmacology
Microbial Sensitivity Tests
*Bacteriophages/physiology
Cefiderocol/pharmacology
*Gram-Negative Aerobic Bacteria/drug effects/virology/physiology
Humans
*Plankton/drug effects/virology
Drug Resistance, Multiple, Bacterial/drug effects
RevDate: 2025-05-16
Analysis of gene expression within individual cells reveals spatiotemporal patterns underlying Vibrio cholerae biofilm development.
PLoS biology, 23(5):e3003187 pii:PBIOLOGY-D-25-00146 [Epub ahead of print].
Bacteria commonly exist in multicellular, surface-attached communities called biofilms. Biofilms are central to ecology, medicine, and industry. The Vibrio cholerae pathogen forms biofilms from single founder cells that, via cell division, mature into three-dimensional structures with distinct, yet reproducible, regional architectures. To define mechanisms underlying biofilm developmental transitions, we establish a single-molecule fluorescence in situ hybridization (smFISH) approach that enables accurate quantitation of spatiotemporal gene-expression patterns in biofilms at cell-scale resolution. smFISH analyses of V. cholerae biofilm regulatory and structural genes demonstrate that, as biofilms mature, overall matrix gene expression decreases, and simultaneously, a pattern emerges in which matrix gene expression becomes largely confined to peripheral biofilm cells. Both quorum sensing and c-di-GMP-signaling are required to generate the proper temporal pattern of matrix gene expression. Quorum sensing signaling is uniform across the biofilm, and thus, c-di-GMP-signaling alone sets the regional matrix gene expression pattern. The smFISH strategy provides insight into mechanisms conferring particular fates to individual biofilm cells.
Additional Links: PMID-40378130
Publisher:
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40378130,
year = {2025},
author = {Johnson, GE and Fei, C and Wingreen, NS and Bassler, BL},
title = {Analysis of gene expression within individual cells reveals spatiotemporal patterns underlying Vibrio cholerae biofilm development.},
journal = {PLoS biology},
volume = {23},
number = {5},
pages = {e3003187},
doi = {10.1371/journal.pbio.3003187},
pmid = {40378130},
issn = {1545-7885},
abstract = {Bacteria commonly exist in multicellular, surface-attached communities called biofilms. Biofilms are central to ecology, medicine, and industry. The Vibrio cholerae pathogen forms biofilms from single founder cells that, via cell division, mature into three-dimensional structures with distinct, yet reproducible, regional architectures. To define mechanisms underlying biofilm developmental transitions, we establish a single-molecule fluorescence in situ hybridization (smFISH) approach that enables accurate quantitation of spatiotemporal gene-expression patterns in biofilms at cell-scale resolution. smFISH analyses of V. cholerae biofilm regulatory and structural genes demonstrate that, as biofilms mature, overall matrix gene expression decreases, and simultaneously, a pattern emerges in which matrix gene expression becomes largely confined to peripheral biofilm cells. Both quorum sensing and c-di-GMP-signaling are required to generate the proper temporal pattern of matrix gene expression. Quorum sensing signaling is uniform across the biofilm, and thus, c-di-GMP-signaling alone sets the regional matrix gene expression pattern. The smFISH strategy provides insight into mechanisms conferring particular fates to individual biofilm cells.},
}
RevDate: 2025-05-17
Inhibition of quorum sensing, biofilm formation, and virulence-related characteristics in shrimp pathogenic Vibrio campbellii by rambutan (Nephelium lappaceum L. cv. Rong Rian) peel extract.
Microbial pathogenesis, 205:107702 pii:S0882-4010(25)00427-9 [Epub ahead of print].
Vibrio campbellii is a significant pathogen in shrimp aquaculture, causing luminous vibriosis and leading to considerable declines in productivity and quality. The rapid emergence of multi-drug and detergent-resistant strains presents a major challenge in controlling this pathogen. This study investigates the inhibitory effects of rambutan peel extract (RPE) on quorum sensing (QS) systems, biofilm formation, and virulence-related traits in V. campbellii. The minimum inhibitory concentration (MIC) of RPE was found to be 2048 μg/ml for the pathogenic strain V. campbellii HY01 and 1024 μg/ml for the non-pathogenic QS reporter strains. Sub-inhibitory concentrations significantly reduced bioluminescence in V. campbellii, indicating interference with QS systems, particularly harveyi autoinducer-1 (HAI-1) and autoinducer-2 (AI-2). RPE disrupted autoinducer detection, down-regulated the expression of QS sensor genes, inhibited phosphorylation, and affected the transcription of QS regulator AphA. Additionally, RPE reduced biofilm formation, swimming motility, caseinase production, and virulence gene expression in the shrimp pathogenic strain HY01. These findings demonstrate the strong anti-QS activity of RPE against V. campbellii by targeting QS systems, phosphorylation pathways, and the master QS regulator. The study highlights the potential of RPE as a sustainable approach to control luminous vibriosis, offering a promising strategy for managing disease outbreaks and improving shrimp health in aquaculture.
Additional Links: PMID-40373944
Publisher:
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40373944,
year = {2025},
author = {Pattano, J and Jintasakul, V and Jantapaso, H and Mittraparp-Arthorn, P},
title = {Inhibition of quorum sensing, biofilm formation, and virulence-related characteristics in shrimp pathogenic Vibrio campbellii by rambutan (Nephelium lappaceum L. cv. Rong Rian) peel extract.},
journal = {Microbial pathogenesis},
volume = {205},
number = {},
pages = {107702},
doi = {10.1016/j.micpath.2025.107702},
pmid = {40373944},
issn = {1096-1208},
abstract = {Vibrio campbellii is a significant pathogen in shrimp aquaculture, causing luminous vibriosis and leading to considerable declines in productivity and quality. The rapid emergence of multi-drug and detergent-resistant strains presents a major challenge in controlling this pathogen. This study investigates the inhibitory effects of rambutan peel extract (RPE) on quorum sensing (QS) systems, biofilm formation, and virulence-related traits in V. campbellii. The minimum inhibitory concentration (MIC) of RPE was found to be 2048 μg/ml for the pathogenic strain V. campbellii HY01 and 1024 μg/ml for the non-pathogenic QS reporter strains. Sub-inhibitory concentrations significantly reduced bioluminescence in V. campbellii, indicating interference with QS systems, particularly harveyi autoinducer-1 (HAI-1) and autoinducer-2 (AI-2). RPE disrupted autoinducer detection, down-regulated the expression of QS sensor genes, inhibited phosphorylation, and affected the transcription of QS regulator AphA. Additionally, RPE reduced biofilm formation, swimming motility, caseinase production, and virulence gene expression in the shrimp pathogenic strain HY01. These findings demonstrate the strong anti-QS activity of RPE against V. campbellii by targeting QS systems, phosphorylation pathways, and the master QS regulator. The study highlights the potential of RPE as a sustainable approach to control luminous vibriosis, offering a promising strategy for managing disease outbreaks and improving shrimp health in aquaculture.},
}
RevDate: 2025-05-15
Effective minocycline treatment enhances clinical Klebsiella pneumoniae infections: Investigation of biofilm resistance mutations and antimicrobial efficacy in pediatric infections.
Microbial pathogenesis pii:S0882-4010(25)00428-0 [Epub ahead of print].
The extensive use of antibacterial agent has led to a steady decline in the clinical exposure of Klebsiella pneumoniae to carbapenems (CPM), creating considerable obstacles for infection control and clinical disinfection. K. pneumoniae utilizes the development of dense biofilms and overexpression of efflux pumps to circumvent the detrimental properties of CPM. Minocycline (MCL) is a promising antibacterial agent that reduces proton motive forces and increases membrane permeability. This study demonstrated the synergistic antibacterial effect of MCL and CPM, which significantly lowered the MIC of CPM-resistant K. pneumoniae. Importantly, using crystal violet and live/dead staining, we found that MCL markedly improved the anti-biofilm efficacy of CPM. Studies assessing reactive oxygen species, alkaline phosphatase leakage, membrane permeability, and RT-PCR indicated that the combination of MCL and CPM induced oxidative stress, enhanced the permeability of K. pneumoniae membrane, and suppressed the overexpression of the efflux pump genes oqxA and oqxB. Additionally, we performed surface disinfection trials on medicinal tools to replicate clinical settings, revealing that MCL and CPM significantly decreased the bacterial burden by 3 log10 CFU/mL. Furthermore, findings from the resistance mutation frequency assays demonstrated that the combinational therapy (MCL + CPM) diminished the emergence of the K. pneumoniae population. Overall, MCL can function as an ancillary agent, augmenting the biofilm efficacy of CPM and attenuating the emergence of resistance mutation, thus prolonging the efficacy of CPM.
Additional Links: PMID-40373940
Publisher:
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40373940,
year = {2025},
author = {Wang, Z and Yuan, L},
title = {Effective minocycline treatment enhances clinical Klebsiella pneumoniae infections: Investigation of biofilm resistance mutations and antimicrobial efficacy in pediatric infections.},
journal = {Microbial pathogenesis},
volume = {},
number = {},
pages = {107703},
doi = {10.1016/j.micpath.2025.107703},
pmid = {40373940},
issn = {1096-1208},
abstract = {The extensive use of antibacterial agent has led to a steady decline in the clinical exposure of Klebsiella pneumoniae to carbapenems (CPM), creating considerable obstacles for infection control and clinical disinfection. K. pneumoniae utilizes the development of dense biofilms and overexpression of efflux pumps to circumvent the detrimental properties of CPM. Minocycline (MCL) is a promising antibacterial agent that reduces proton motive forces and increases membrane permeability. This study demonstrated the synergistic antibacterial effect of MCL and CPM, which significantly lowered the MIC of CPM-resistant K. pneumoniae. Importantly, using crystal violet and live/dead staining, we found that MCL markedly improved the anti-biofilm efficacy of CPM. Studies assessing reactive oxygen species, alkaline phosphatase leakage, membrane permeability, and RT-PCR indicated that the combination of MCL and CPM induced oxidative stress, enhanced the permeability of K. pneumoniae membrane, and suppressed the overexpression of the efflux pump genes oqxA and oqxB. Additionally, we performed surface disinfection trials on medicinal tools to replicate clinical settings, revealing that MCL and CPM significantly decreased the bacterial burden by 3 log10 CFU/mL. Furthermore, findings from the resistance mutation frequency assays demonstrated that the combinational therapy (MCL + CPM) diminished the emergence of the K. pneumoniae population. Overall, MCL can function as an ancillary agent, augmenting the biofilm efficacy of CPM and attenuating the emergence of resistance mutation, thus prolonging the efficacy of CPM.},
}
RevDate: 2025-05-15
Removal of antibiotic and disinfectant compounds from digested pig manure by an aerobic hybrid biofilm process.
The Science of the total environment, 982:179600 pii:S0048-9697(25)01241-0 [Epub ahead of print].
Using nutrient-rich manure as fertiliser on agricultural land improves crop yield, biodiversity, soil structure, water and nutrient availability. However, manure often contains high levels of antibiotics, as only 10-30 % are metabolised by the animal, thus, soil application contributes to the spread of antibiotics and antibiotic-resistant genes (ARGs). As anaerobic digestion fails to remove the antibiotics and ARGs completely, this study investigates aerobic moving bed biofilm reactors (MBBRs) as post-treatment. The dissipation of sulfadiazine, sulfamethoxazole, ofloxacin, ciprofloxacin, roxithromycin, erythromycin, tylosin, tetracycline, chlortetracycline, benzalkonium chloride C12 and -C14 (BAC-12 and -14) was observed in small laboratory batch MBBRs with digested pig manure. Proficiency testing resulted in an overall removal of 92 %. Sulfamethoxazole and erythromycin were removed by >99 % within 12 and 23 days, respectively. The digestate exhibited high concentrations of benzalkonium biocides, i.e., BAC-12 and -14 (800 μg/L and 172 μg/L, respectively), highlighting the necessity for post-treatment before application to agricultural soil. Within 23 days, the aerobic MBBRs achieved 89 % and 93 % degradation of BAC-12 and -14, respectively. The biofilms improved the total removal by 19 % and BAC degradation by 61-68 % while increasing bacterial diversity. The MBBR-operation increased the abundance of the genera Paracoccus, Parvibaculum, and Clostridium sensu stricto 1. The sulfonamide-resistance genes were the most abundant ARGs (96 % and 98 % in the sludge and carrier biofilm, respectively). The ARG-abundance increased after antibiotic spiking and declined during incubation, reducing direct ARG spread to the environment by degrading antimicrobial concentrations. We, therefore, propose to treat anaerobically digested manure by aerobic biofilm treatment for antibiotic removal.
Additional Links: PMID-40373682
Publisher:
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40373682,
year = {2025},
author = {Larsson, Y and Nikolausz, M and Møller, HB and Bester, K},
title = {Removal of antibiotic and disinfectant compounds from digested pig manure by an aerobic hybrid biofilm process.},
journal = {The Science of the total environment},
volume = {982},
number = {},
pages = {179600},
doi = {10.1016/j.scitotenv.2025.179600},
pmid = {40373682},
issn = {1879-1026},
abstract = {Using nutrient-rich manure as fertiliser on agricultural land improves crop yield, biodiversity, soil structure, water and nutrient availability. However, manure often contains high levels of antibiotics, as only 10-30 % are metabolised by the animal, thus, soil application contributes to the spread of antibiotics and antibiotic-resistant genes (ARGs). As anaerobic digestion fails to remove the antibiotics and ARGs completely, this study investigates aerobic moving bed biofilm reactors (MBBRs) as post-treatment. The dissipation of sulfadiazine, sulfamethoxazole, ofloxacin, ciprofloxacin, roxithromycin, erythromycin, tylosin, tetracycline, chlortetracycline, benzalkonium chloride C12 and -C14 (BAC-12 and -14) was observed in small laboratory batch MBBRs with digested pig manure. Proficiency testing resulted in an overall removal of 92 %. Sulfamethoxazole and erythromycin were removed by >99 % within 12 and 23 days, respectively. The digestate exhibited high concentrations of benzalkonium biocides, i.e., BAC-12 and -14 (800 μg/L and 172 μg/L, respectively), highlighting the necessity for post-treatment before application to agricultural soil. Within 23 days, the aerobic MBBRs achieved 89 % and 93 % degradation of BAC-12 and -14, respectively. The biofilms improved the total removal by 19 % and BAC degradation by 61-68 % while increasing bacterial diversity. The MBBR-operation increased the abundance of the genera Paracoccus, Parvibaculum, and Clostridium sensu stricto 1. The sulfonamide-resistance genes were the most abundant ARGs (96 % and 98 % in the sludge and carrier biofilm, respectively). The ARG-abundance increased after antibiotic spiking and declined during incubation, reducing direct ARG spread to the environment by degrading antimicrobial concentrations. We, therefore, propose to treat anaerobically digested manure by aerobic biofilm treatment for antibiotic removal.},
}
RevDate: 2025-05-15
Regulation of type 3 fimbria expression by RstA affects biofilm formation and virulence in Klebsiella pneumoniae ATCC43816.
Microbiology spectrum [Epub ahead of print].
Klebsiella pneumoniae causes both community-acquired and healthcare-associated infections, presenting a major therapeutic challenge to global public health. RstBA is a common two-component regulatory system that controls downstream gene expression in certain Enterobacteriaceae species. However, the role of RstBA in K. pneumoniae infection remains unknown. To determine its function, a wild-type K. pneumoniae strain (ATCC43816) and rstA mutant and complementation strains were constructed. Phenotypic experiments and in vivo animal infection assays demonstrated that deletion of rstA decreased virulence and biofilm formation. RNA sequencing analysis of ATCC43816 and rstA mutant strains was performed to study the regulatory mechanisms, revealing differential expression of genes involved in arginine and proline metabolism, phenylalanine metabolism, and quorum sensing. In addition, the mrkI and the mrkABCDF gene cluster, which regulates and encodes type 3 fimbriae, exhibited lower expression in the absence of rstA, possibly related to decreased virulence and biofilm formation. Quantitative real-time reverse transcription PCR, promoter activity assays, and electrophoretic mobility shift assays were conducted to identify the transcriptional regulation of mrkI and mrkABCDF by rstA. Our findings show that rstA regulates type 3 fimbriae expression by regulating mrkI indirectly and regulating mrkA directly by binding to its promoter. This study provides new insights into the functional importance of RstA in regulating biofilm formation and virulence in K. pneumoniae.IMPORTANCEKlebsiella pneumoniae is an opportunistic pathogen that has become a significant cause of community-acquired and nosocomial infections. The rise of hypervirulent and multi-drug-resistant K. pneumoniae poses a significant threat to public health. The two-component regulatory system is a typical signal-sensing and stress-response system widely distributed in bacteria, playing a critical regulatory role in bacterial infection. Through in vivo and in vitro experiments, we demonstrate that rstA regulates the expression of type 3 fimbriae by regulating mrkI indirectly and mrkA directly, thereby playing an essential role in the virulence and biofilm formation of K. pneumoniae. Understanding the regulatory mechanism of RstA in K. pneumoniae provides a proof-of-concept for identifying new genetic targets for controlling K. pneumoniae infection, which may aid in the development of therapeutic drugs.
Additional Links: PMID-40372035
Publisher:
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40372035,
year = {2025},
author = {Zhang, X and Zhai, Y and Zhu, J and Zhu, Z and Wen, Y and Gao, Q and Wang, L and Lin, J and Qian, Y and Chen, L and Du, H},
title = {Regulation of type 3 fimbria expression by RstA affects biofilm formation and virulence in Klebsiella pneumoniae ATCC43816.},
journal = {Microbiology spectrum},
volume = {},
number = {},
pages = {e0307624},
doi = {10.1128/spectrum.03076-24},
pmid = {40372035},
issn = {2165-0497},
abstract = {Klebsiella pneumoniae causes both community-acquired and healthcare-associated infections, presenting a major therapeutic challenge to global public health. RstBA is a common two-component regulatory system that controls downstream gene expression in certain Enterobacteriaceae species. However, the role of RstBA in K. pneumoniae infection remains unknown. To determine its function, a wild-type K. pneumoniae strain (ATCC43816) and rstA mutant and complementation strains were constructed. Phenotypic experiments and in vivo animal infection assays demonstrated that deletion of rstA decreased virulence and biofilm formation. RNA sequencing analysis of ATCC43816 and rstA mutant strains was performed to study the regulatory mechanisms, revealing differential expression of genes involved in arginine and proline metabolism, phenylalanine metabolism, and quorum sensing. In addition, the mrkI and the mrkABCDF gene cluster, which regulates and encodes type 3 fimbriae, exhibited lower expression in the absence of rstA, possibly related to decreased virulence and biofilm formation. Quantitative real-time reverse transcription PCR, promoter activity assays, and electrophoretic mobility shift assays were conducted to identify the transcriptional regulation of mrkI and mrkABCDF by rstA. Our findings show that rstA regulates type 3 fimbriae expression by regulating mrkI indirectly and regulating mrkA directly by binding to its promoter. This study provides new insights into the functional importance of RstA in regulating biofilm formation and virulence in K. pneumoniae.IMPORTANCEKlebsiella pneumoniae is an opportunistic pathogen that has become a significant cause of community-acquired and nosocomial infections. The rise of hypervirulent and multi-drug-resistant K. pneumoniae poses a significant threat to public health. The two-component regulatory system is a typical signal-sensing and stress-response system widely distributed in bacteria, playing a critical regulatory role in bacterial infection. Through in vivo and in vitro experiments, we demonstrate that rstA regulates the expression of type 3 fimbriae by regulating mrkI indirectly and mrkA directly, thereby playing an essential role in the virulence and biofilm formation of K. pneumoniae. Understanding the regulatory mechanism of RstA in K. pneumoniae provides a proof-of-concept for identifying new genetic targets for controlling K. pneumoniae infection, which may aid in the development of therapeutic drugs.},
}
RevDate: 2025-05-16
Comparative analysis of antibiotic resistance and biofilm formation in Enterococcus spp. across One Health domains.
FEMS microbes, 6:xtaf005.
The rise of antibiotic-resistant bacteria is a critical issue across various ecological interfaces, highlighting the need for a One Health approach. Enterococcus spp., known for their ability to acquire and disseminate resistance, serve as an excellent model due to their presence in diverse hosts and environments. This study investigates antimicrobial resistance, biofilm formation capacity, and the efficacy of antibiotics on biofilm biomass reduction in isolates from multiple sources. A total of 197 Enterococcus isolates were used. Antimicrobial resistance was determined using the Kirby-Bauer disc diffusion method, and minimum inhibitory concentrations were tested against vancomycin, tetracycline, and ampicillin. Biofilm formation capacity was assessed, and 10 biofilm-formers were subjected to minimum biofilm inhibitory concentration (MBIC) tests to evaluate biofilm biomass reduction. The results showed high resistance rates to erythromycin (84.5%), ciprofloxacin (59.4%), and tetracycline (44.4%), with moderate resistance to ampicillin (36.2%), chloramphenicol (28%), and vancomycin (24.7%). Biofilm formation was observed in 65% of the isolates, with Enterococcus hirae producing the most biofilm biomass. Vancomycin and ampicillin were more effective in reducing biofilm biomass than tetracycline. Ampicillin-resistant isolates produced more biofilm, suggesting a link between resistance and biofilm formation. This study highlights the complexity of antibiotic-resistant Enterococcus spp. and their biofilms, emphasizing the need for research on One Health.
Additional Links: PMID-40370517
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40370517,
year = {2025},
author = {Silva, V and Freitas, C and Ribeiro, J and Igrejas, G and Poeta, P},
title = {Comparative analysis of antibiotic resistance and biofilm formation in Enterococcus spp. across One Health domains.},
journal = {FEMS microbes},
volume = {6},
number = {},
pages = {xtaf005},
pmid = {40370517},
issn = {2633-6685},
abstract = {The rise of antibiotic-resistant bacteria is a critical issue across various ecological interfaces, highlighting the need for a One Health approach. Enterococcus spp., known for their ability to acquire and disseminate resistance, serve as an excellent model due to their presence in diverse hosts and environments. This study investigates antimicrobial resistance, biofilm formation capacity, and the efficacy of antibiotics on biofilm biomass reduction in isolates from multiple sources. A total of 197 Enterococcus isolates were used. Antimicrobial resistance was determined using the Kirby-Bauer disc diffusion method, and minimum inhibitory concentrations were tested against vancomycin, tetracycline, and ampicillin. Biofilm formation capacity was assessed, and 10 biofilm-formers were subjected to minimum biofilm inhibitory concentration (MBIC) tests to evaluate biofilm biomass reduction. The results showed high resistance rates to erythromycin (84.5%), ciprofloxacin (59.4%), and tetracycline (44.4%), with moderate resistance to ampicillin (36.2%), chloramphenicol (28%), and vancomycin (24.7%). Biofilm formation was observed in 65% of the isolates, with Enterococcus hirae producing the most biofilm biomass. Vancomycin and ampicillin were more effective in reducing biofilm biomass than tetracycline. Ampicillin-resistant isolates produced more biofilm, suggesting a link between resistance and biofilm formation. This study highlights the complexity of antibiotic-resistant Enterococcus spp. and their biofilms, emphasizing the need for research on One Health.},
}
RevDate: 2025-05-16
Effects of Biofilm Formation on Gastrointestinal Tolerance, Mucoadhesion and Transcriptomic Responses of Probiotics.
Food science & nutrition, 13(5):e70206.
Probiotic health benefits may be affected by decreased viability during food storage and gastrointestinal transit. Although microencapsulation is an effective protective strategy, its application to probiotics is limited. Currently, research on probiotic biofilms is expanding, with these biofilms being recognized as the fourth generation of probiotics. This study aimed to investigate the effects of biofilm formation on gastrointestinal tolerance and mucoadhesion of three different probiotics: Ligilactobacillus salivarius Li01 (L. salivarius Li01), Bifidobacterium longum (B. longum), and Bifidobacterium pseudocatenulatum (B. pseudocatenulatum). Biofilm growth was markedly inhibited by low pH and high bile salt concentrations. The formation of biofilms greatly improved the survival of all three strains under simulated gastrointestinal conditions. The biofilms increased intestinal adhesion and surface hydrophobicity in B. longum and L. salivarius Li01, while reducing adhesion in B. pseudocatenulatum due to decreased hydrophobicity. Moreover, transcriptomic analysis of L. salivarius Li01 identified 157 differentially expressed genes, enriched in pathways including ABC transporters, quorum sensing, purine metabolism, arginine biosynthesis, the phosphotransferase system (PTS), RNA polymerase, and the NOD-like receptor signaling pathway. In conclusion, the formation of biofilms enhances gastrointestinal tolerance and intestinal adhesion of probiotics, presenting great applied potential in increasing the efficacy of probiotics.
Additional Links: PMID-40370418
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40370418,
year = {2025},
author = {Gao, W and Jing, H and Qiu, B and Zhang, S and Zhang, J and Xu, L and Ba, F and Xie, S and Liu, XM and Li, L and Yao, M},
title = {Effects of Biofilm Formation on Gastrointestinal Tolerance, Mucoadhesion and Transcriptomic Responses of Probiotics.},
journal = {Food science & nutrition},
volume = {13},
number = {5},
pages = {e70206},
pmid = {40370418},
issn = {2048-7177},
abstract = {Probiotic health benefits may be affected by decreased viability during food storage and gastrointestinal transit. Although microencapsulation is an effective protective strategy, its application to probiotics is limited. Currently, research on probiotic biofilms is expanding, with these biofilms being recognized as the fourth generation of probiotics. This study aimed to investigate the effects of biofilm formation on gastrointestinal tolerance and mucoadhesion of three different probiotics: Ligilactobacillus salivarius Li01 (L. salivarius Li01), Bifidobacterium longum (B. longum), and Bifidobacterium pseudocatenulatum (B. pseudocatenulatum). Biofilm growth was markedly inhibited by low pH and high bile salt concentrations. The formation of biofilms greatly improved the survival of all three strains under simulated gastrointestinal conditions. The biofilms increased intestinal adhesion and surface hydrophobicity in B. longum and L. salivarius Li01, while reducing adhesion in B. pseudocatenulatum due to decreased hydrophobicity. Moreover, transcriptomic analysis of L. salivarius Li01 identified 157 differentially expressed genes, enriched in pathways including ABC transporters, quorum sensing, purine metabolism, arginine biosynthesis, the phosphotransferase system (PTS), RNA polymerase, and the NOD-like receptor signaling pathway. In conclusion, the formation of biofilms enhances gastrointestinal tolerance and intestinal adhesion of probiotics, presenting great applied potential in increasing the efficacy of probiotics.},
}
RevDate: 2025-05-17
CmpDate: 2025-05-15
Bio-informed synthesis of marine-sourced indole derivatives: suppressing gram-negative bacteria biofilm and virulence.
BMC biology, 23(1):134.
Biofilms cling to surfaces to form complex architectures allowing their bacterial creators to acquire multidrug resistance and claiming countless lives worldwide. Therefore, finding novel compounds that affect virulence and biofilm-forming capacity of resistant pathogenic bacteria is imperative. Recently, we identified indole-based compounds that possess anti-biofilm properties in coral-associated bacteria. We succeeded in efficiently synthesizing two of these compounds, 1,1'-bisindole (NN) and 2,3-dihydro-2,2'-bisindole (DIV). They were found to attenuate biofilms of gram-negative bacterial pathogens, including Pseudomonas aeruginosa and Acinetobacter baumannii. Combining these compounds with the antibiotic tobramycin resulted in significant biofilm inhibition, particularly in the eradication of mature P. aeruginosa biofilms. Both of the bisindole derivatives, suppressed a number of bacterial virulence factors, reduced bacterial adhesion, and improved survival rates in infected Caenorhabditis elegans and human lung epithelial cell models. Transcriptome analyses of the bacteria treated with these compounds revealed that NN repressed or upregulated 307 genes when compared to untreated P. aeruginosa. These bacteria-derived molecules act in resistance-quenching and are potentially important candidates for inclusion in treatment protocols. The use of compounds that prevent the biofilm from accumulating the high cell densities critical to its structural and functional maintenance represents significant progress in the management of bacterial persistence. Therefore, a possible clinical implementation of these innovative compounds holds a promising future.
Additional Links: PMID-40369603
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40369603,
year = {2025},
author = {Golberg, K and Elouarzaki, K and Kagan, BE and Shagan, M and Shemesh, N and Kramarsky-Winter, E and Ben-Zvi, A and Nebenzahl, YM and Marks, RS and Kushmaro, A},
title = {Bio-informed synthesis of marine-sourced indole derivatives: suppressing gram-negative bacteria biofilm and virulence.},
journal = {BMC biology},
volume = {23},
number = {1},
pages = {134},
pmid = {40369603},
issn = {1741-7007},
support = {8528620//NIBN/ ; },
mesh = {*Biofilms/drug effects ; *Indoles/pharmacology/chemical synthesis/chemistry ; Virulence/drug effects ; *Anti-Bacterial Agents/pharmacology/chemical synthesis/chemistry ; Caenorhabditis elegans/microbiology/drug effects ; *Pseudomonas aeruginosa/drug effects/physiology/pathogenicity ; Animals ; *Acinetobacter baumannii/drug effects/physiology ; Humans ; *Gram-Negative Bacteria/drug effects/physiology/pathogenicity ; },
abstract = {Biofilms cling to surfaces to form complex architectures allowing their bacterial creators to acquire multidrug resistance and claiming countless lives worldwide. Therefore, finding novel compounds that affect virulence and biofilm-forming capacity of resistant pathogenic bacteria is imperative. Recently, we identified indole-based compounds that possess anti-biofilm properties in coral-associated bacteria. We succeeded in efficiently synthesizing two of these compounds, 1,1'-bisindole (NN) and 2,3-dihydro-2,2'-bisindole (DIV). They were found to attenuate biofilms of gram-negative bacterial pathogens, including Pseudomonas aeruginosa and Acinetobacter baumannii. Combining these compounds with the antibiotic tobramycin resulted in significant biofilm inhibition, particularly in the eradication of mature P. aeruginosa biofilms. Both of the bisindole derivatives, suppressed a number of bacterial virulence factors, reduced bacterial adhesion, and improved survival rates in infected Caenorhabditis elegans and human lung epithelial cell models. Transcriptome analyses of the bacteria treated with these compounds revealed that NN repressed or upregulated 307 genes when compared to untreated P. aeruginosa. These bacteria-derived molecules act in resistance-quenching and are potentially important candidates for inclusion in treatment protocols. The use of compounds that prevent the biofilm from accumulating the high cell densities critical to its structural and functional maintenance represents significant progress in the management of bacterial persistence. Therefore, a possible clinical implementation of these innovative compounds holds a promising future.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
*Biofilms/drug effects
*Indoles/pharmacology/chemical synthesis/chemistry
Virulence/drug effects
*Anti-Bacterial Agents/pharmacology/chemical synthesis/chemistry
Caenorhabditis elegans/microbiology/drug effects
*Pseudomonas aeruginosa/drug effects/physiology/pathogenicity
Animals
*Acinetobacter baumannii/drug effects/physiology
Humans
*Gram-Negative Bacteria/drug effects/physiology/pathogenicity
RevDate: 2025-05-17
CmpDate: 2025-05-15
Cas3 of type I-Fa CRISPR-Cas system upregulates bacterial biofilm formation and virulence in Acinetobacter baumannii.
Communications biology, 8(1):750.
Acinetobacter baumannii (A. baumannii) is an important pathogen causing various nosocomial infections. CRISPR-Cas system is the adaptive immune system of bacteria, which is also closely related to the drug resistance and virulence of bacteria. However, the effect and mechanism of cas3 (type I-Fa) in A. baumannii is still unclear. In this study, we successfully constructed a cas3 deletion mutant (19606Δcas3) and complemented strain (19606Δcas3/pcas3) to study the regulatory mechanism of type I-Fa cas3 on bacterial virulence. Our results showed that deletion of cas3(type I-Fa) significantly reduced the biofilm formation, virulence and pathogenicity to mice. The organ bacterial load of mice infected with cas3 deletion strain was significantly reduced, the lung inflammation was slightly changed, and the serum cytokine level was also decreased. All results demonstrated that cas3 enhanced the virulence and pathogenicity of A. baumannii. Mechanism analysis showed that deletion of cas3 can lead to the down-regulation of virulence factors such as biofilm formation related factors and outer membrane protein A(ompA). In addition, cas3 was also involved in the regulation of carbon metabolism and oxidative phosphorylation pathway of A. baumannii. Altogether, our study may provide cas3 as a therapeutic target in the future because of the close link to the virulence of A. baumannii.
Additional Links: PMID-40369106
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40369106,
year = {2025},
author = {Guo, T and Yang, J and Zhou, N and Sun, X and Huan, C and Lin, T and Bao, G and Hu, J and Li, G},
title = {Cas3 of type I-Fa CRISPR-Cas system upregulates bacterial biofilm formation and virulence in Acinetobacter baumannii.},
journal = {Communications biology},
volume = {8},
number = {1},
pages = {750},
pmid = {40369106},
issn = {2399-3642},
support = {82073611//National Natural Science Foundation of China (National Science Foundation of China)/ ; },
mesh = {*Biofilms/growth & development ; *Acinetobacter baumannii/pathogenicity/genetics/physiology ; Animals ; Virulence/genetics ; Mice ; *CRISPR-Cas Systems ; *Acinetobacter Infections/microbiology ; *Bacterial Proteins/genetics/metabolism ; Gene Expression Regulation, Bacterial ; Virulence Factors/genetics/metabolism ; *CRISPR-Associated Proteins/genetics/metabolism ; Female ; Mice, Inbred BALB C ; },
abstract = {Acinetobacter baumannii (A. baumannii) is an important pathogen causing various nosocomial infections. CRISPR-Cas system is the adaptive immune system of bacteria, which is also closely related to the drug resistance and virulence of bacteria. However, the effect and mechanism of cas3 (type I-Fa) in A. baumannii is still unclear. In this study, we successfully constructed a cas3 deletion mutant (19606Δcas3) and complemented strain (19606Δcas3/pcas3) to study the regulatory mechanism of type I-Fa cas3 on bacterial virulence. Our results showed that deletion of cas3(type I-Fa) significantly reduced the biofilm formation, virulence and pathogenicity to mice. The organ bacterial load of mice infected with cas3 deletion strain was significantly reduced, the lung inflammation was slightly changed, and the serum cytokine level was also decreased. All results demonstrated that cas3 enhanced the virulence and pathogenicity of A. baumannii. Mechanism analysis showed that deletion of cas3 can lead to the down-regulation of virulence factors such as biofilm formation related factors and outer membrane protein A(ompA). In addition, cas3 was also involved in the regulation of carbon metabolism and oxidative phosphorylation pathway of A. baumannii. Altogether, our study may provide cas3 as a therapeutic target in the future because of the close link to the virulence of A. baumannii.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
*Biofilms/growth & development
*Acinetobacter baumannii/pathogenicity/genetics/physiology
Animals
Virulence/genetics
Mice
*CRISPR-Cas Systems
*Acinetobacter Infections/microbiology
*Bacterial Proteins/genetics/metabolism
Gene Expression Regulation, Bacterial
Virulence Factors/genetics/metabolism
*CRISPR-Associated Proteins/genetics/metabolism
Female
Mice, Inbred BALB C
RevDate: 2025-05-14
A Prospective Pilot Clinical Study reveals a promising non-toxic anti-biofilm activity of Gentamicin-EDTA-Na2 Central Venous Catheter Lock Solution.
International journal of infectious diseases : IJID : official publication of the International Society for Infectious Diseases pii:S1201-9712(25)00157-2 [Epub ahead of print].
OBJECTIVES: The treatment of long-term intravenous catheter-related bloodstream infections (LTIVC-related BSI) often requires catheter removal or a conservative treatment using intra-catheter locks, with a 50-60% success rate. We previously demonstrated the synergistic effect of a combination of gentamicin and EDTA-Na2 against bacterial biofilms. We performed a phase 1/2 clinical trial to assess the tolerance and efficacy of the genta-EDTA-Na2 locks for the conservative treatment of LTIVC-related BSI.
METHODS: Prospective study including adult patients with a monomicrobial uncomplicated LTIVC-related BSI caused by a gentamicin-susceptible coagulase-negative staphylococci, Enterobacterales or Pseudomonas aeruginosa.
PRIMARY OBJECTIVE: assess the safety and efficacy at Day 40 (D40) of genta-EDTA-Na2 locks by evaluating the frequency of clinical and microbiological cure 30 days after the end of treatment (D40).
RESULTS: Eight patients were included. A complete follow-up was obtained for 7 patients, 6 of which met cure criteria. The single patient whose follow-up was incomplete met all criteria for cure at D23. A single microbiological failure occurred (relapse of P. aeruginosa LTIVC-related BSI). Two patients experienced at least one serious adverse event; none were attributed to the genta-EDTA-Na2 locks.
CONCLUSION: Genta-EDTA-Na2 used as intra-catheter locks may be a promising anti-biofilm candidate to be studied in a randomized controlled trial.
Additional Links: PMID-40368083
Publisher:
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40368083,
year = {2025},
author = {Lebeaux, D and Souhail, B and Van, TB and Fouler, LL and Lafaurie, M and Lepeule, R and Canoui, E and de Lastours, V and Froissart, A and Blez, D and Beloin, C and Ghigo, JM and Pirot, F and Dhelens, C and Fernandes-Pellerin, S},
title = {A Prospective Pilot Clinical Study reveals a promising non-toxic anti-biofilm activity of Gentamicin-EDTA-Na2 Central Venous Catheter Lock Solution.},
journal = {International journal of infectious diseases : IJID : official publication of the International Society for Infectious Diseases},
volume = {},
number = {},
pages = {107933},
doi = {10.1016/j.ijid.2025.107933},
pmid = {40368083},
issn = {1878-3511},
abstract = {OBJECTIVES: The treatment of long-term intravenous catheter-related bloodstream infections (LTIVC-related BSI) often requires catheter removal or a conservative treatment using intra-catheter locks, with a 50-60% success rate. We previously demonstrated the synergistic effect of a combination of gentamicin and EDTA-Na2 against bacterial biofilms. We performed a phase 1/2 clinical trial to assess the tolerance and efficacy of the genta-EDTA-Na2 locks for the conservative treatment of LTIVC-related BSI.
METHODS: Prospective study including adult patients with a monomicrobial uncomplicated LTIVC-related BSI caused by a gentamicin-susceptible coagulase-negative staphylococci, Enterobacterales or Pseudomonas aeruginosa.
PRIMARY OBJECTIVE: assess the safety and efficacy at Day 40 (D40) of genta-EDTA-Na2 locks by evaluating the frequency of clinical and microbiological cure 30 days after the end of treatment (D40).
RESULTS: Eight patients were included. A complete follow-up was obtained for 7 patients, 6 of which met cure criteria. The single patient whose follow-up was incomplete met all criteria for cure at D23. A single microbiological failure occurred (relapse of P. aeruginosa LTIVC-related BSI). Two patients experienced at least one serious adverse event; none were attributed to the genta-EDTA-Na2 locks.
CONCLUSION: Genta-EDTA-Na2 used as intra-catheter locks may be a promising anti-biofilm candidate to be studied in a randomized controlled trial.},
}
RevDate: 2025-05-14
Effect of vmeB gene deletion on biofilm formation and enrofloxacin resistance in Vibrio parahaemolyticus.
Microbial pathogenesis pii:S0882-4010(25)00406-1 [Epub ahead of print].
Vibrio parahaemolyticus was a foodborne pathogen that commonly found in seafood products and seriously threatened human food safety. Biofilm played a vital role in the resistance of V. parahaemolyticus, and the relationship between efflux pump encode gene vmeB and biofilm formation of V. parahaemolyticus remained poorly understood. In this study, the ATCC33846ΔvmeB deletion strain and ΔvmeB/pBAD33T-vmeB complement strain were constructed to reveal the mechanism that RND efflux pump vmeB gene regulated the biofilm of V. parahaemolyticus-mediated enrofloxacin resistance. The biofilm formation, motility and transcription levels related to outer membrane genes (ompA, ompH, ompN, ompU, ompV, ompW, ompX), flagella genes (fliA, fliC, fliS) and pilus genes (pilO, pilP) were explored. The results indicated that biofilm formation potential and motility were significantly decreased, the transcription levels of genes associated with the outer membrane, flagella, and pilus genes were significantly reduced in ATCC33846ΔvmeB. Additionally, Fourier transform infrared spectroscopy (FTIR) results demonstrated DNA integrity was compromised, protein structure was disrupted, and membrane lipid content was elevated in ATCC33846ΔvmeB. Meanwhile, ATCC33846ΔvmeB cells were observed to be damaged by scanning electron microscopy, and the flow cytometry analysis demonstrated a significant increase in cell apoptosis rate. Finally, the drug resistance results exhibited that the sensitivity of ATCC33846ΔvmeB to enrofloxacin is fivefold lower compared to ATCC33846. These results elucidate the drug resistance mechanism of vmeB regulates V. parahaemolyticus ATCC33846 biofilm, potentially providing new opportunities to develop inhibitors that specifically alter the characteristics of the biofilm matrix and thereby affect the enrofloxacin resistance of V. parahaemolyticus.
Additional Links: PMID-40368070
Publisher:
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40368070,
year = {2025},
author = {Li, X and Ma, Q and Xu, S and Xie, C and Gu, C and Wu, J and Feng, Q and Tan, X},
title = {Effect of vmeB gene deletion on biofilm formation and enrofloxacin resistance in Vibrio parahaemolyticus.},
journal = {Microbial pathogenesis},
volume = {},
number = {},
pages = {107681},
doi = {10.1016/j.micpath.2025.107681},
pmid = {40368070},
issn = {1096-1208},
abstract = {Vibrio parahaemolyticus was a foodborne pathogen that commonly found in seafood products and seriously threatened human food safety. Biofilm played a vital role in the resistance of V. parahaemolyticus, and the relationship between efflux pump encode gene vmeB and biofilm formation of V. parahaemolyticus remained poorly understood. In this study, the ATCC33846ΔvmeB deletion strain and ΔvmeB/pBAD33T-vmeB complement strain were constructed to reveal the mechanism that RND efflux pump vmeB gene regulated the biofilm of V. parahaemolyticus-mediated enrofloxacin resistance. The biofilm formation, motility and transcription levels related to outer membrane genes (ompA, ompH, ompN, ompU, ompV, ompW, ompX), flagella genes (fliA, fliC, fliS) and pilus genes (pilO, pilP) were explored. The results indicated that biofilm formation potential and motility were significantly decreased, the transcription levels of genes associated with the outer membrane, flagella, and pilus genes were significantly reduced in ATCC33846ΔvmeB. Additionally, Fourier transform infrared spectroscopy (FTIR) results demonstrated DNA integrity was compromised, protein structure was disrupted, and membrane lipid content was elevated in ATCC33846ΔvmeB. Meanwhile, ATCC33846ΔvmeB cells were observed to be damaged by scanning electron microscopy, and the flow cytometry analysis demonstrated a significant increase in cell apoptosis rate. Finally, the drug resistance results exhibited that the sensitivity of ATCC33846ΔvmeB to enrofloxacin is fivefold lower compared to ATCC33846. These results elucidate the drug resistance mechanism of vmeB regulates V. parahaemolyticus ATCC33846 biofilm, potentially providing new opportunities to develop inhibitors that specifically alter the characteristics of the biofilm matrix and thereby affect the enrofloxacin resistance of V. parahaemolyticus.},
}
RevDate: 2025-05-14
Green Synthesized Antimicrobial Peptides and Nanoparticles from Phoenix dactylifera: Evaluation of Anti-biofilm, Anti-Pathogenic and Anti-diabetic Activities.
Microbial pathogenesis pii:S0882-4010(25)00425-5 [Epub ahead of print].
In recent years, an increasing demand for medicinal plants to control diseases for human well being has resulted in the usage of such plants in our society. Current study aims to determine the role of antimicrobial peptides and nanoparticles synthesized by aqueous extract of date fruit palm as antimicrobial, anti-pathogenic, anti-diabetic agents and their effect on hematological parameters. A total of 32 chemical compounds, 21 unique antimicrobial peptides (proteins) and 10 low molecular weight antioxidant peptides were identified in the aqueous extract of Phoenix dactylifera. FT-NMR analysis of the plant extract also revealed presence of various antimicrobial compounds in aqueous extract of Phoenix dactylifera. The aqueous extract of Phoenix dactylifera showed significantly higher antimicrobial and anti-biofilm activities due to the synthesis of antimicrobial peptides (proteins) and nanoparticles such as selenium and titanium. Synthesis of antimicrobial peptides and nanoparticles damaged intracellular and extracellular structure of microbes by breaking functional groups of Pseudomonas aeruginosa. In the absence of extract, Pseudomonas aeruginosa expressed multiple pathogenic proteins; however almost all of these proteins were inhibited when Pseudomonas aeruginosa was treated with aqueous extract of date fruit palm. During metabolism, reactive oxygen species are produced and subsequently detoxified by low molecular weight antioxidant peptides and nanoparticles such as selenium and titanium found in Phoenix dactylifera. Blood glucose level significantly (80.4 mg/dl on day 5, 69.6 mg/dl on day 15) reduced in albino rats when fed with aqueous extract (300 mg/kg body weight) and alloxan (100 mg/kg body weight) compared to control rats (which did not receive alloxin) and rats fed with alloxan (100 mg/kg body weight) at day 5 and day 15. Antioxidant levels significantly increased in presence of aqueous extracts. The aqueous extract of date palm fruit significantly decreased hematological parameters in albino rats compared to control groups, in a dose-dependent manner. Duncan's multiple range test confirmed effect of extracts of Phoenix dactylifera were significantly (p<0.05) different for each measured parameter. These results confirmed that Phoenix dactylifera synthesized antimicrobial peptides and nanoparticles, which showed Phoenix dactylifera as an alternative medicine for treating various diseases.
Additional Links: PMID-40368068
Publisher:
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40368068,
year = {2025},
author = {Wani, PA and Wani, TA and Olajumoke Oluwagbemisola, OS and Alotaibi, RN and Fawzhia, SJ and Zargar, S and Ahmed, B},
title = {Green Synthesized Antimicrobial Peptides and Nanoparticles from Phoenix dactylifera: Evaluation of Anti-biofilm, Anti-Pathogenic and Anti-diabetic Activities.},
journal = {Microbial pathogenesis},
volume = {},
number = {},
pages = {107700},
doi = {10.1016/j.micpath.2025.107700},
pmid = {40368068},
issn = {1096-1208},
abstract = {In recent years, an increasing demand for medicinal plants to control diseases for human well being has resulted in the usage of such plants in our society. Current study aims to determine the role of antimicrobial peptides and nanoparticles synthesized by aqueous extract of date fruit palm as antimicrobial, anti-pathogenic, anti-diabetic agents and their effect on hematological parameters. A total of 32 chemical compounds, 21 unique antimicrobial peptides (proteins) and 10 low molecular weight antioxidant peptides were identified in the aqueous extract of Phoenix dactylifera. FT-NMR analysis of the plant extract also revealed presence of various antimicrobial compounds in aqueous extract of Phoenix dactylifera. The aqueous extract of Phoenix dactylifera showed significantly higher antimicrobial and anti-biofilm activities due to the synthesis of antimicrobial peptides (proteins) and nanoparticles such as selenium and titanium. Synthesis of antimicrobial peptides and nanoparticles damaged intracellular and extracellular structure of microbes by breaking functional groups of Pseudomonas aeruginosa. In the absence of extract, Pseudomonas aeruginosa expressed multiple pathogenic proteins; however almost all of these proteins were inhibited when Pseudomonas aeruginosa was treated with aqueous extract of date fruit palm. During metabolism, reactive oxygen species are produced and subsequently detoxified by low molecular weight antioxidant peptides and nanoparticles such as selenium and titanium found in Phoenix dactylifera. Blood glucose level significantly (80.4 mg/dl on day 5, 69.6 mg/dl on day 15) reduced in albino rats when fed with aqueous extract (300 mg/kg body weight) and alloxan (100 mg/kg body weight) compared to control rats (which did not receive alloxin) and rats fed with alloxan (100 mg/kg body weight) at day 5 and day 15. Antioxidant levels significantly increased in presence of aqueous extracts. The aqueous extract of date palm fruit significantly decreased hematological parameters in albino rats compared to control groups, in a dose-dependent manner. Duncan's multiple range test confirmed effect of extracts of Phoenix dactylifera were significantly (p<0.05) different for each measured parameter. These results confirmed that Phoenix dactylifera synthesized antimicrobial peptides and nanoparticles, which showed Phoenix dactylifera as an alternative medicine for treating various diseases.},
}
RevDate: 2025-05-14
Derazantinib Inhibits the Planktonic Growth and Biofilm Formation of Staphylococcus aureus by Binding Membrane Phospholipids and Disrupting the Cell Membrane.
ACS infectious diseases [Epub ahead of print].
Derazantinib (DZB), a pan-fibroblast growth factor receptor (FGFR) inhibitor, exhibits potent activity against FGFR1-3 kinases and has been clinically approved for antitumor therapy. However, its antibacterial properties remain unknown. Here, we demonstrated that DZB displays broad-spectrum activity against Staphylococcus aureus (S. aureus), with minimum inhibitory concentrations (MICs) ranging from 6.25 to 25 μM. DZB exhibited more rapid and stronger bactericidal activity against planktonic cells of both MSSA and MRSA compared to vancomycin. DZB at 6.25 μM robustly inhibited biofilm formation and even eradicated mature biofilms. Global proteomic profiling revealed that DZB's antibacterial mechanism might involve disruption of microbial glycolysis/gluconeogenesis pathways. Furthermore, in vitro selection of DZB-induced resistant S. aureus resulted in a 2-fold increase in MIC, and whole-genome sequencing of this derivative isolate identified amino acid mutations in membrane-associated proteins. DZB was found to compromise bacterial membrane integrity, as evidenced by increased membrane permeability, and the membrane damage was also confirmed by scanning electron microscopy (SEM). The antibacterial activity of DZB was neutralized by the addition of exogenous phosphatidylglycerol and cardiolipin. Biolayer interferometry assays demonstrated a strong interaction between DZB and cardiolipin, suggesting membrane phospholipid targeting as a key mechanism. Lastly, DZB displayed a robust inhibitory effect against intracellular S. aureus SA113 and showed excellent in vivo anti-MRSA infection in both Galleria mellonella larvae and murine infection models. In summary, our findings established DZB as a promising anti-S. aureus agent with dual antibacterial and antibiofilm activities by disrupting the cell membrane through targeting membrane phospholipids.
Additional Links: PMID-40367508
Publisher:
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40367508,
year = {2025},
author = {Liu, X and Li, C and Meng, Q and Chen, C and Lai, Y and Wang, H and Yu, Z and Li, D and Chen, Z and Hou, T},
title = {Derazantinib Inhibits the Planktonic Growth and Biofilm Formation of Staphylococcus aureus by Binding Membrane Phospholipids and Disrupting the Cell Membrane.},
journal = {ACS infectious diseases},
volume = {},
number = {},
pages = {},
doi = {10.1021/acsinfecdis.4c01020},
pmid = {40367508},
issn = {2373-8227},
abstract = {Derazantinib (DZB), a pan-fibroblast growth factor receptor (FGFR) inhibitor, exhibits potent activity against FGFR1-3 kinases and has been clinically approved for antitumor therapy. However, its antibacterial properties remain unknown. Here, we demonstrated that DZB displays broad-spectrum activity against Staphylococcus aureus (S. aureus), with minimum inhibitory concentrations (MICs) ranging from 6.25 to 25 μM. DZB exhibited more rapid and stronger bactericidal activity against planktonic cells of both MSSA and MRSA compared to vancomycin. DZB at 6.25 μM robustly inhibited biofilm formation and even eradicated mature biofilms. Global proteomic profiling revealed that DZB's antibacterial mechanism might involve disruption of microbial glycolysis/gluconeogenesis pathways. Furthermore, in vitro selection of DZB-induced resistant S. aureus resulted in a 2-fold increase in MIC, and whole-genome sequencing of this derivative isolate identified amino acid mutations in membrane-associated proteins. DZB was found to compromise bacterial membrane integrity, as evidenced by increased membrane permeability, and the membrane damage was also confirmed by scanning electron microscopy (SEM). The antibacterial activity of DZB was neutralized by the addition of exogenous phosphatidylglycerol and cardiolipin. Biolayer interferometry assays demonstrated a strong interaction between DZB and cardiolipin, suggesting membrane phospholipid targeting as a key mechanism. Lastly, DZB displayed a robust inhibitory effect against intracellular S. aureus SA113 and showed excellent in vivo anti-MRSA infection in both Galleria mellonella larvae and murine infection models. In summary, our findings established DZB as a promising anti-S. aureus agent with dual antibacterial and antibiofilm activities by disrupting the cell membrane through targeting membrane phospholipids.},
}
RevDate: 2025-05-14
Comparison of Anti-Biofilm Potential of Rhamnolipid Biosurfactant, Chemical Agents, and Coliphage Against E. coli Biofilm.
Applied biochemistry and biotechnology [Epub ahead of print].
Biosurfactants are amphipathic microbial products that are released extracellularly or remain attached to the cell surface. The strong biofilm anti-adhesive and anti-biofilm properties of biosurfactants make them suitable candidates for application aimed at destroying troublesome bacterial biofilm. To investigate the anti-adhesion and biofilm disruptive properties of natural rhamnolipid biosurfactant, targeted isolation of a hydrocarbonoclastic bacteria from hydrocarbon-contaminated soil of Dakor, Gujarat, India, led to the isolation of bacteria producing biosurfactant, identified as Pseudomonas aeruginosa. DKR. The orcinol test preliminarily indicated that the biosurfactant was indeed rhamnolipid. The Fourier transform infrared spectroscopy and nuclear magnetic resonance further confirmed the biosurfactant as rhamnolipid. Pseudomonas aeruginosa DKR produced 25 mg/ml rhamnolipid that reduced the surface tension to 22.4 mN/m and possessed CMC (critical micellar concentration) of 130 mg/L. Sub-inhibitory dilution (0.25 mg/ml) of purified rhamnolipid DKR demonstrated superior antiadhesive and antibiofilm properties against biofilm-forming E. coli strains isolated from drinking water coolers in comparison to subinhibitory concentrations of common chemical surfactants, chelating agents, and weak acids used. Coliphage AM isolated on selected E. coli strains as hosts also demonstrated an appreciable biofilm anti-adhesive and anti-biofilm effect at 10[6] Pfu/ml. This study emphasizes the utility of rhamnolipid biosurfactant DKR and Coliphage AM in lieu of chemicals as natural and eco-friendly agents in applications to eradicate biofilm from drinking water cooling containers, etc.
Additional Links: PMID-40366538
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40366538,
year = {2025},
author = {Thakare, AM and Nerurkar, AS},
title = {Comparison of Anti-Biofilm Potential of Rhamnolipid Biosurfactant, Chemical Agents, and Coliphage Against E. coli Biofilm.},
journal = {Applied biochemistry and biotechnology},
volume = {},
number = {},
pages = {},
pmid = {40366538},
issn = {1559-0291},
abstract = {Biosurfactants are amphipathic microbial products that are released extracellularly or remain attached to the cell surface. The strong biofilm anti-adhesive and anti-biofilm properties of biosurfactants make them suitable candidates for application aimed at destroying troublesome bacterial biofilm. To investigate the anti-adhesion and biofilm disruptive properties of natural rhamnolipid biosurfactant, targeted isolation of a hydrocarbonoclastic bacteria from hydrocarbon-contaminated soil of Dakor, Gujarat, India, led to the isolation of bacteria producing biosurfactant, identified as Pseudomonas aeruginosa. DKR. The orcinol test preliminarily indicated that the biosurfactant was indeed rhamnolipid. The Fourier transform infrared spectroscopy and nuclear magnetic resonance further confirmed the biosurfactant as rhamnolipid. Pseudomonas aeruginosa DKR produced 25 mg/ml rhamnolipid that reduced the surface tension to 22.4 mN/m and possessed CMC (critical micellar concentration) of 130 mg/L. Sub-inhibitory dilution (0.25 mg/ml) of purified rhamnolipid DKR demonstrated superior antiadhesive and antibiofilm properties against biofilm-forming E. coli strains isolated from drinking water coolers in comparison to subinhibitory concentrations of common chemical surfactants, chelating agents, and weak acids used. Coliphage AM isolated on selected E. coli strains as hosts also demonstrated an appreciable biofilm anti-adhesive and anti-biofilm effect at 10[6] Pfu/ml. This study emphasizes the utility of rhamnolipid biosurfactant DKR and Coliphage AM in lieu of chemicals as natural and eco-friendly agents in applications to eradicate biofilm from drinking water cooling containers, etc.},
}
RevDate: 2025-05-15
The Effect of Sub-Minimal Inhibitory Concentrations of Daptomycin and Linezolid on Biofilm Formation of Methicillin Resistant Staphylococcus aureus Isolated from Clinical Samples.
Turkish journal of pharmaceutical sciences, 22(2):131-139.
OBJECTIVES: The aim of this study was to determine the development of in vitro resistance and changes in biofilm forming abilities in methicillin-resistant Staphylococcus aureus (MRSA) isolates exposed to sub-minimal inhibitory concentrations (sub-MICs) of daptomycin and linezolid; and to investigate the presence of the methicillin resistance gene (mecA) and the biofilm-associated genes (icaA, icaD) by polymerase chain reaction.
MATERIALS AND METHODS: This study was carried out with thirty-two MRSA isolates. The susceptibility of the isolates to daptomycin and linezolid was investigated by the broth microdilution method, and MIC values were determined (1[st] MIC). After serial passages, the 2[nd] MIC and the 3[rd] MIC values were similarly detected. Before and after serial passages, the biofilm-forming abilities of MRSA isolates were examined using the microtiter plate (MTP) method.
RESULTS: When the daptomycin and linezolid 1[st] MIC and 3[rd] MIC values of the isolates were compared, there was a 2-8 fold increase in linezolid (p<0.05) and a 4-32 fold increase in daptomycin (p<0.05). According to the MTP method, 20 (62.5%) of the 32 isolates formed biofilm at various levels, while 12 (37.5%) did not form biofilm. After the second series of passages, biofilm formation was observed in 19 (59.4%) isolates with daptomycin (p>0.05) and in 16 (50%) isolates with linezolid (p>0.05). The mecA gene was found in all isolates. Also, icaA and icaD genes were detected in 31 (96.9%) of 32 MRSA isolates.
CONCLUSION: MRSA isolates exposed to sub-MICs of the antibiotics daptomycin and linezolid were observed to form biofilms at varying levels or to lose their ability to form biofilms. The induction, reduction or eradication of biofilm depended on the type of antibiotic and the MRSA isolate.
Additional Links: PMID-40366226
Publisher:
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid40366226,
year = {2025},
author = {Bal, H and Altanlar, N and Yıldız, S},
title = {The Effect of Sub-Minimal Inhibitory Concentrations of Daptomycin and Linezolid on Biofilm Formation of Methicillin Resistant Staphylococcus aureus Isolated from Clinical Samples.},
journal = {Turkish journal of pharmaceutical sciences},
volume = {22},
number = {2},
pages = {131-139},
doi = {10.4274/tjps.galenos.2025.26723},
pmid = {40366226},
issn = {2148-6247},
abstract = {OBJECTIVES: The aim of this study was to determine the development of in vitro resistance and changes in biofilm forming abilities in methicillin-resistant Staphylococcus aureus (MRSA) isolates exposed to sub-minimal inhibitory concentrations (sub-MICs) of daptomycin and linezolid; and to investigate the presence of the methicillin resistance gene (mecA) and the biofilm-associated genes (icaA, icaD) by polymerase chain reaction.
MATERIALS AND METHODS: This study was carried out with thirty-two MRSA isolates. The susceptibility of the isolates to daptomycin and linezolid was investigated by the broth microdilution method, and MIC values were determined (1[st] MIC). After serial passages, the 2[nd] MIC and the 3[rd] MIC values were similarly detected. Before and after serial passages, the biofilm-forming abilities of MRSA isolates were examined using the microtiter plate (MTP) method.
RESULTS: When the daptomycin and linezolid 1[st] MIC and 3[rd] MIC values of the isolates were compared, there was a 2-8 fold increase in linezolid (p<0.05) and a 4-32 fold increase in daptomycin (p<0.05). According to the MTP method, 20 (62.5%) of the 32 isolates formed biofilm at various levels, while 12 (37.5%) did not form biofilm. After the second series of passages, biofilm formation was observed in 19 (59.4%) isolates with daptomycin (p>0.05) and in 16 (50%) isolates with linezolid (p>0.05). The mecA gene was found in all isolates. Also, icaA and icaD genes were detected in 31 (96.9%) of 32 MRSA isolates.
CONCLUSION: MRSA isolates exposed to sub-MICs of the antibiotics daptomycin and linezolid were observed to form biofilms at varying levels or to lose their ability to form biofilms. The induction, reduction or eradication of biofilm depended on the type of antibiotic and the MRSA isolate.},
}
▼ ▼ LOAD NEXT 100 CITATIONS
ESP Quick Facts
ESP Origins
In the early 1990's, Robert Robbins was a faculty member at Johns Hopkins, where he directed the informatics core of GDB — the human gene-mapping database of the international human genome project. To share papers with colleagues around the world, he set up a small paper-sharing section on his personal web page. This small project evolved into The Electronic Scholarly Publishing Project.
ESP Support
In 1995, Robbins became the VP/IT of the Fred Hutchinson Cancer Research Center in Seattle, WA. Soon after arriving in Seattle, Robbins secured funding, through the ELSI component of the US Human Genome Project, to create the original ESP.ORG web site, with the formal goal of providing free, world-wide access to the literature of classical genetics.
ESP Rationale
Although the methods of molecular biology can seem almost magical to the uninitiated, the original techniques of classical genetics are readily appreciated by one and all: cross individuals that differ in some inherited trait, collect all of the progeny, score their attributes, and propose mechanisms to explain the patterns of inheritance observed.
ESP Goal
In reading the early works of classical genetics, one is drawn, almost inexorably, into ever more complex models, until molecular explanations begin to seem both necessary and natural. At that point, the tools for understanding genome research are at hand. Assisting readers reach this point was the original goal of The Electronic Scholarly Publishing Project.
ESP Usage
Usage of the site grew rapidly and has remained high. Faculty began to use the site for their assigned readings. Other on-line publishers, ranging from The New York Times to Nature referenced ESP materials in their own publications. Nobel laureates (e.g., Joshua Lederberg) regularly used the site and even wrote to suggest changes and improvements.
ESP Content
When the site began, no journals were making their early content available in digital format. As a result, ESP was obliged to digitize classic literature before it could be made available. For many important papers — such as Mendel's original paper or the first genetic map — ESP had to produce entirely new typeset versions of the works, if they were to be available in a high-quality format.
ESP Help
Early support from the DOE component of the Human Genome Project was critically important for getting the ESP project on a firm foundation. Since that funding ended (nearly 20 years ago), the project has been operated as a purely volunteer effort. Anyone wishing to assist in these efforts should send an email to Robbins.
ESP Plans
With the development of methods for adding typeset side notes to PDF files, the ESP project now plans to add annotated versions of some classical papers to its holdings. We also plan to add new reference and pedagogical material. We have already started providing regularly updated, comprehensive bibliographies to the ESP.ORG site.
ESP Picks from Around the Web (updated 28 JUL 2024 )
Old Science
Weird Science
Treating Disease with Fecal Transplantation
Fossils of miniature humans (hobbits) discovered in Indonesia
Paleontology
Dinosaur tail, complete with feathers, found preserved in amber.
Astronomy
Mysterious fast radio burst (FRB) detected in the distant universe.
Big Data & Informatics
Big Data: Buzzword or Big Deal?
Hacking the genome: Identifying anonymized human subjects using publicly available data.