Viewport Size Code:
Login | Create New Account
picture

  MENU

About | Classical Genetics | Timelines | What's New | What's Hot

About | Classical Genetics | Timelines | What's New | What's Hot

icon

Bibliography Options Menu

icon
QUERY RUN:
HITS:
PAGE OPTIONS:
Hide Abstracts   |   Hide Additional Links
NOTE:
Long bibliographies are displayed in blocks of 100 citations at a time. At the end of each block there is an option to load the next block.

Bibliography on: Biofilm

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 11 Jun 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: 2025-06-09

Cattò C, Fassi EMA, Grazioso G, et al (2025)

Insights on Zosteric Acid Analogues Activity Against Candida albicans Biofilm Formation.

ACS omega, 10(21):22285-22295.

Zosteric acid (ZA), or p-(sulphooxy)-cinnamic acid, is a secondary metabolite of the seagrass Zostera marina able to reduce biofilm formation of a wide range of bacteria and fungi, through a nonbiocidal mode of action. However, the lack of information concerning the specific chemical structural elements responsible for ZA's antibiofilm activity has hindered the scaling up of this green-based technology for real applications. In this study, a small library of molecules based on ZA scaffold diversity was screened against the eukaryotic fungus Candida albicans, in order to identify the key chemical features of ZA necessary for inhibiting fungal biofilm at sublethal concentrations. Results, supported by multivariate statistical analysis, revealed that the presence of (i) the trans (E) double bond, (ii) the free carboxylic group in the side chain, and (iii) the para substitution with a hydroxyl group were all instrumental for maintaining the antibiofilm activity of the molecules. Additionally, molecular modeling studies suggested that the best performing derivatives interacted with NADP-(H) quinone oxidoreductase, influencing the microbial redox balance.

RevDate: 2025-06-09

Yuan X, Chao C, Niu J, et al (2025)

Mechanistic insights into nitrogen removal performance and electron competition with mixed electron donor supply in a biofilm electrode reactor.

Eco-Environment & Health, 4(2):100153.

In this study, a unique electrode configuration in the form of an "inverted T" was developed in the biofilm electrode reactor (BER), enabling superior nitrogen removal via the synergistic effect of hydrogen autotrophic denitrification and heterotrophic denitrification. In contrast to the sole heterotrophic denitrification in the biofilm reactor (BR), weak electric stimulation in the BER system promoted in situ hydrogen production as well as electron transport and utilization, resulting in a notable 20% improvement in NO 3 - removal efficiency for both influent COD/N ratios. Conversely, notable NO 2 - accumulation occurred under both COD/N ratios, with concentrations ranging from 6.0 to 8.0 mg/L. The enrichment of non-heterotrophic denitrifiers, such as Thermomonas, Pelomonas, and Hydrogenophaga, was observed in the BER with a relative abundance exceeding 1.0%, contributing to the hydrogen autotrophic denitrification pathway. Based on the outcomes of the multiple electron donor utilization in the coexistence of different electron acceptor combinations, despite H2 serving as an additional electron donor in the BER, electron competition was still detectable. Notably, nitrite reductase (Nir) emerged as the weakest competitor, resulting in a constrained NO 2 - reduction capacity. Based on the analysis of the electron competition characteristic, the potential NO 3 - metabolic pathway in the BER system was primarily driven by heterotrophic denitrification processes. The introduced electricity in the BER system was favorable for facilitating nitrogen removal through in situ production of hydrogen, direct supply of electrons from the electrode, improvement of functional microbial activity, and enhancement of enzymatic activity.

RevDate: 2025-06-08
CmpDate: 2025-06-08

García-Viñola V, Ezenarro J, Reguant C, et al (2025)

Interaction effects of fumaric acid, pH and ethanol on the growth of lactic and acetic acid bacteria in planktonic and biofilm states.

Food microbiology, 131:104808.

The microbial stability of wine can be compromised by the presence of lactic acid bacteria (LAB) and acetic acid bacteria (AAB), which can cause spoilage via off flavour production, increased acetic acid production, or biofilm formation. To manage the growth of LAB in winemaking, fumaric acid (FA) has been proposed as an alternative to traditional antimicrobial agents, such as sulfur dioxide (SO2). This study aimed to evaluate the inhibitory effects of FA on the growth of LAB and AAB based on the influence of pH and ethanol in a synthetic wine-like medium. The research involved the determination of the individual, 2 × 2 combined, and combined minimum inhibitory concentrations (MICs) of fumaric acid, pH, and ethanol. Specifically, the MIC90 was defined as the concentration required to inhibit the growth of more than 90 % of the initial population, and the MIC50 was defined as the concentration required to inhibit the growth of more than 50 % of the initial population. These thresholds were assessed in 19 bacterial strains (13 LAB and 6 AAB strains) at pH values of 3.5 and 4.0 and ethanol concentrations of 0, 4, 8 and 12 % v/v. Additionally, the impact of FA on biofilm formation was evaluated in the ten bacterial strains that were observed to be most resistant to FA. The results revealed that the inhibitory effects of FA were enhanced at lower pH values and at higher ethanol concentrations. LAB strains (such as Oenococcus oeni) were particularly sensitive to FA, whereas non-Oenococcus LAB strains demonstrated resistance to concentrations exceeding 2 g/L under the tested pH (3.5-4.0) and ethanol (0-12 % v/v) conditions. AAB strains (such as Acetobacter aceti) tolerated FA concentrations greater than 2 g/L at pH 4.0 in the absence of ethanol; however, the susceptibility increased with increasing ethanol concentrations and decreasing pH. Furthermore, FA significantly inhibited biofilm formation (particularly at a pH of 3.5 and ethanol concentrations greater than 8 % v/v). In conclusion, when combined with low pH and high ethanol concentrations, FA offers a promising strategy for controlling bacterial growth and biofilm formation in winemaking. This approach has the potential to complement or replace the use of traditional chemical preservatives, such as SO2.

RevDate: 2025-06-08

Gopalasamy K, Krishnamoorthy S, Somasundaram J, et al (2025)

Impact of Multispecies Biofilm on the Chemical and Mechanical Characteristics of Radicular Dentin from Diabetic and Non-Diabetic Patients: An in-vitro Study.

Journal of endodontics pii:S0099-2399(25)00319-X [Epub ahead of print].

INTRODUCTION: This in-vitro study examined the effect of a multispecies biofilm on the chemical characteristics and mechanical properties of root dentin from patients with or without type 2 diabetes mellitus (DM).

METHODS: Intact mandibular molars were obtained from diabetic and non-diabetic donors. Rectangular root dentin beams were prepared and categorized based on age (40-60 and 61-80 years), presence/absence of DM, and the site of dentin beam extraction (mesiodistal/buccolingual). Pentosidine, collagen cross-linking ratio, and mineral-to-collagen ratio were determined by Fourier-transform infrared spectroscopy (FTIR) and fatigue resistance was evaluated by the four-point flexure test to failure with or without exposure to a multispecies biofilm for 21 days.

RESULTS: DM and biofilm exposure significantly increased pentosidine, mineral-to-collagen ratio, and collagen cross-linking ratio in root dentin from both age groups (P<.05). Control root dentin from the 61-80 years group had significantly lower fatigue strength than root dentin from the 40-60 years group (P<.05). DM reduced the fatigue resistance of root dentin but not significantly (P>.05). After biofilm exposure, root dentin with DM had significantly lower fatigue resistance than root dentin without DM (P<.05). Biofilm exposure significantly reduced the fatigue resistance of root dentin with or without DM when compared with the controls only in the 40-60 years group (P<.05).

CONCLUSIONS: Aging decreased the fatigue resistance of root dentin. DM and biofilm exposure increased pentosidine, mineral-to-collagen ratio, and collagen cross-linking in root dentin across both age groups. Biofilm exposure further reduced the fatigue resistance of root dentin with DM compared to root dentin without DM.

RevDate: 2025-06-09

Shankar S, Murthy AN, Rachitha P, et al (2025)

Retraction notice to "Silk sericin conjugated magnesium oxide nanoparticles for its antioxidant, anti-aging, and anti-biofilm activities" [Environ. Res. 223 (2023) 115421].

Environmental research, 282:122031 pii:S0013-9351(25)01282-4 [Epub ahead of print].

RevDate: 2025-06-08

Hennebique A, Monge-Ruiz J, Roger-Margueritat M, et al (2025)

The hospital sink drain biofilm resistome is independent of the corresponding microbiota, the environment and disinfection measures.

Water research, 284:123902 pii:S0043-1354(25)00810-3 [Epub ahead of print].

In hospitals, the transmission of antibiotic-resistant bacteria (ARB) may occur via biofilms present in sink drains, which can lead to infections. Despite the potential role of sink drains in the transmission of ARB in nosocomial infections, routine surveillance of these drains is lacking in most hospitals. As a result, there is currently no comprehensive understanding of the transmission of ARB and the dissemination of antimicrobial resistance genes (ARGs) and associated mobile genetic elements (MGEs) via sink drains. This study employed a multifaceted approach to monitor the total aerobic bacteria as well as the presence of carbapenemase-producing Enterobacterales (CPEs), the microbiota and the resistome of sink drain biofilms (SDBs) and hospital wastewater (WW) of two separate intensive care units (ICUs) in the same healthcare facility in France. Samples of SDB and WW were collected on a monthly basis, from January to April 2023, in the neonatal (NICU) and the adult (AICU) ICUs of Grenoble Alpes University Hospital. In the NICU, sink drain disinfection with surfactants was performed routinely. In the AICU, routine disinfection is not carried out. Culturable aerobic bacteria were quantified on non-selective media, and CPEs were screened using two selective agars. Isolates were identified by MALDI-TOF MS, and antibiotic susceptibility testing (AST) was performed on Enterobacterales and P. aeruginosa. The resistome was analyzed by high-throughput qPCR targeting >80 ARGs and MGEs. The overall bacterial microbiota was assessed via full-length 16S rRNA sequencing. No CPEs were isolated from SDBs in either ICU by bacterial culture. Culture-independent approaches revealed an overall distinct microbiota composition of the SDBs in the two ICUs. The AICU SDBs were dominated by pathogens containing Gram-negative bacterial genera including Pseudomonas, Stenotrophomona, Klebsiella, and Gram-positive Staphylococcus, while the NICU SDBs were dominated by the Gram-negative genera Achromobacter, Serratia, and Acidovorax, as well as the Gram-positive genera Weisella and Lactiplantibacillus. In contrast, the resistome of the SDBs exhibited no significant differences between the two ICUs, indicating that the abundance of ARGs and MGEs is independent of microbiota composition and disinfection practices. The AICU WW exhibited more distinct aerobic bacteria than the NICU WW. In addition, the AICU WW yielded 15 CPEs, whereas the NICU WW yielded a single CPE. All the CPEs were characterized at the species level. The microbiota of the NICU and AICU WW samples differed from their respective SDBs and exhibited distinct variations over the four-month period:the AICU WW contained a greater number of genes conferring resistance to quinolones and integron integrase genes, whereas the NICU WW exhibited a higher abundance of streptogramin resistance genes. Our study demonstrated that the resistome of the hospital SDBs in the two ICUs of the investigated healthcare institute is independent of the microbiota, the environment, and the local disinfection measures. However, the prevalence of CPEs in the WW pipes collecting the waste from the investigated drains differed. These findings offer valuable insights into the resilience of resistance genes in SDBs in ICUs, underscoring the necessity for innovative strategies to combat antimicrobial resistance in clinical environments.

RevDate: 2025-06-06

Zhang R, Li W, Guo Z, et al (2025)

Valence Electron Fluctuation in a High-Entropy Oxide Heterojunction Enables Collaborative Photodynamic and Mild-Thermal Therapy for Cutaneous Biofilm Infections.

ACS nano [Epub ahead of print].

Mild photothermal therapy combined with photodynamic therapy has emerged as an effective treatment for antibiotic-resistant infection. However, controlling operation temperature within a safe range during reactive oxygen species (ROS) production remains a challenge. Herein, we present a functional heterojunction consisting of Ti3C2Tx-MXene and (CoCrFeMnNi)3O4 high-entropy oxide (HEO) featuring a valence electron fluctuation effect, achieving a highly efficient treatment of biofilm-associated infections in wounds and abscesses under mild conditions where skin temperature remains below 42.3 °C. We found that under near-infrared light irradiation, photogenerated hot electrons from MXene are efficiently transferred to the HEO surface, serving as abundant electron sources. The electron fluctuation effect of the HEO enables the rapid enrichment and activation of oxygen molecules in microenvironments, significantly enhancing ROS generation. Simultaneously, the built-in electric field at the MXene-HEO interface suppresses electron-hole recombination, minimizing excessive heat generation and ensuring efficient photothermal-photodynamic synergy. The accelerated generation of ROS inhibits the synthesis of adenosine triphosphate (ATP) by disrupting the bacterial respiratory chain complex (RCC), which significantly inhibits the expression of ATP-dependent molecular chaperone genes groEL and ClpP, compromising bacterial heat resistance and virulence to achieve mild thermal therapy. Moreover, it also shows superior benefits in tissue regeneration, collagen deposition, and angiogenesis while alleviating the inflammation, exhibiting a robust solution for drug-resistant bacterial biofilms in cutaneous tissues. Our work highlights the potential of HEO functional heterojunctions for safe and effective mild-temperature biomedical therapies and paves the way for advanced strategies in combating biofilm-associated infections through rational material design and engineering.

RevDate: 2025-06-06
CmpDate: 2025-06-06

Ravidà A, Dias DR, Lemke R, et al (2025)

Efficacy of Decontamination Methods for Biofilm Removal from Dental Implant Surfaces and Reosseointegration: An AAP/AO Systematic Review on Peri-implant Diseases and Conditions.

The International journal of oral & maxillofacial implants.

PURPOSE: To evaluate the nonclinical evidence concerning the efficacy of different decontamination methods in facilitating reosseointegration, eliminating biofilm from implant surfaces, and their potential to induce adverse surface modifications and release of material remnants.

MATERIALS AND METHODS: Systematic electronic and manual searches were conducted to identify publications involving animal or human block biopsies, ex vivo/in situ studies, and in vitro studies. Mechanical, chemical, and electrolytic methods for implant decontamination were presented in a descriptive analysis.

RESULTS: A total of 121 studies were included, namely 46 involving animal/human biopsies, 39 ex vivo/in situ experiments, and 36 in vitro investigations. No modality demonstrated significant superiority in terms of reosseointegration outcomes. Ex vivo, in situ, and in vitro studies reported that greater biofilm removal from implant surfaces occurred with polyetheretherketone (PEEK) ultrasonic tips, air-powder abrasive (APA), erbium: yttrium-aluminum-garnet (Er:YAG) laser, and electrolytic cleaning. Minimal surface alterations were noted with soaked cotton pellets, APA, specific settings of Er:YAG laser, erbium, chromium: yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser, electrolytic treatment, and cold atmospheric plasma. Titanium or stainless steel curettes, ultrasonic tips, titanium brushes, and implantoplasty induced significant surface alterations and peak flattening of implant threads. Plastic and carbon curettes as well as PEEK ultrasonic tips and APA left material remnants.

CONCLUSIONS: Implant reosseointegration is possible following appropriate surface decontamination. Application of Er:YAG laser, electrolytic cleaning, and APA stand out as the methods that most closely embody the ideal characteristics of an effective decontamination protocol.

RevDate: 2025-06-05

Ferreira Fonseca de Fraga FB, Dalberto PF, Bizarro CV, et al (2025)

Egg proteins of Anagasta kuehniella (Lepidoptera: Pyralidae) inhibit Staphylococcus epidermidis biofilm formation.

Microbial pathogenesis pii:S0882-4010(25)00505-4 [Epub ahead of print].

Bacterial biofilms are increasing its tolerance to conventional antimicrobial treatments. In this context biofilm formation becomes an important target to control pathogenic bacteria. Arthropods are known to be an important source of natural products; however, investigations exploring the biological activities of arthropod eggs are scarce. So, in this study we investigated the antibiofilm activity of the Mediterranean flour moth Anagasta kuehniella compounds against Staphylococcus epidermidis. The antibiofilm activity of organic and aqueous extractions performed on the eggs was assessed using the crystal violet method and scanning electron microscopy (SEM). Egg's aqueous extract (AE) inhibits up to 65% biofilm formation by S. epidermidis. Heat and enzymatic treatments indicated that activity was related to protein. A partial purified active fraction (F9) was obtained by size exclusion chromatography and SDS-PAGE were performed using AE and F9. Mass spectrometry was used to identify the proteins in the F9. SEM analysis showed this fraction inhibits bacterial aggregates in treated S. epidermidis biofilms without alteration on bacterial cell morphology. Our results showed that proteins present in A. kuehniella eggs inhibit biofilm formation without killing S. epidermidis and reinforces the idea that arthropods are a potential source of natural products useful for biotechnology.

RevDate: 2025-06-05

Brindhadevi K, Le QH, Salmen SH, et al (2025)

Retraction notice to "In vitro biofilm inhibition efficacy of Aerva lanata flower extract against Gram negative and Gram-positive biofilm forming bacteria and toxicity analysis using Artemia salina" [Environ. Res. 238-P1 (2023) 117118].

Environmental research, 282:121993 pii:S0013-9351(25)01244-7 [Epub ahead of print].

RevDate: 2025-06-05

Wang CT, Vasumathi K, Tumboimbela JRW, et al (2025)

Temperature-driven changes in biofilm formation and electrochemical performance of deep-sea inoculum in microbial fuel cells.

Bioelectrochemistry (Amsterdam, Netherlands), 166:109012 pii:S1567-5394(25)00115-X [Epub ahead of print].

Microbial fuel cells (MFCs) generate electricity by converting organic materials and utilizing electroactive bacteria, where anodic biofilms play a vital role in electron transfer and controlling internal resistance. The adaptation of deep-sea microbial communities to diverse environmental conditions, particularly the effects of temperature on biofilm formation and MFC efficiency in high-salinity environments, remains under-explored. This study aims to fill this gap by examining how different temperatures (4 °C (F35), 25 °C (R35), and 37 °C (I35)) affect anodic biofilm formation and MFC performance. The research employs deep-sea sediment inoculum from the South China Sea to enhance understanding of microbial adaptability and optimize performance in extreme conditions. Among the tested conditions, I35 demonstrated the highest current and power densities at 172.49 mA/m[2] and 20.09 mW/m[2], representing increases of approximately 129 % and 350 % compared to F35. R35 displayed moderate output. Microbial analysis revealed that I35 had the highest CFU count at 7.67 × 10[7] CFU/mL, with Gram staining and colony morphology indicating greater diversity and a higher abundance of electroactive Gram-negative populations at elevated temperatures. Performance improved with increased temperature; however, the power gains were more significant than variations in microbial counts, underscoring the importance of microbial composition, biofilm conductivity, and electron transfer efficiency. Despite having viable bacteria, F35 showed low output due to a less electroactive community and considerable charge transfer resistance. These findings highlight the need to enhance microbial quality, not just quantity, to improve MFC performance in extreme conditions and support the future application of thermally adapted biofilms in high-salinity MFC systems.

RevDate: 2025-06-07

Ma L, Liu Y, Zheng X, et al (2025)

Isolation and characterization of methicillin-resistant Staphylococcus aureus phage SPB against MRSA planktonic cells and biofilm.

Frontiers in microbiology, 16:1554182.

Methicillin-resistant Staphylococcus aureus (MRSA) is a common antibiotic-resistant pathogen. MRSA and its biofilm pose a great threat to the food industry. In this study, we characterized the biological properties and antibacterial efficacy of phages through the double-layer plate method, transmission electron microscopy (TEM), whole-genome sequencing (WGS), bioinformatic analyses, fluorescence microscopy, and biofilm eradication assays. The results demonstrated that phage SPB is a virulent member of the genus Kayvirus (subfamily Twortvirinae), exhibited a broad host range spanning Staphylococcus species. It effectively lysed 97.3% (36/37) of clinical MRSA isolates and 100.0% (10/10) of coagulase-negative staphylococci strains tested. The optimal multiplicity of infection (MOI) was determined to be 1, with a latent period of 10 min. Environmental stability assays revealed that phage SPB maintained infectivity across temperatures ranging from 4°C to 50°C and pH values between 4 and 11. Genomic analysis showed that phage SPB possesses a 143,170 bp genome with a G+C content of 30.2%, encoding 218 putative coding sequences (CDSs), 3 tRNAs, and no virulence factors were identified through in software screening. Phage SPB exhibited potent inhibition of planktonic bacterial growth. Furthermore, at varying multiplicities of infection (MOIs), it significantly suppressed biofilm formation and eradicated pre-existing biofilms, with statistical significance (P < 0.001). These results suggest that phage SPB can be used as a potential antimicrobial agent to prevent and remove MRSA and its biofilm from food processing.

RevDate: 2025-06-04

Hamad D, Hassanein EHM, Salem SH, et al (2025)

Synthesis of ZIF-67 Nanoparticles for Camel Whey Protein Delivery: Promising Antioxidant, Anti-inflammatory, Anticancer Effects, and Anti-biofilm Activity.

Molecular biotechnology [Epub ahead of print].

Camel whey protein (CWP) offers various health benefits, including immune enhancement, anti-inflammatory, anticancer, and antibacterial properties. It also possesses antioxidant activity. However, its limited efficacy and stability restrict its broader application. Metal-organic frameworks (MOFs) are crystalline materials composed of multiple organic groups and metal ions, known for their unique structural properties. In this study, we aimed to synthesize and evaluate the biological activity of a CWP-Co-MOF conjugate. The structural characterization of the synthesized materials was conducted using X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and energy-dispersive X-ray (EDX) analysis. The comparison of the XRD and FTIR patterns of ZIF-67, CWP and CWP-Co-MOF conjugate indicate successful conjugation of CWP with ZIF-67, confirming the structural integrity of the conjugate. The EDX maps further corroborate the effective conjugation of CWP with ZIF-67. The conjugated CWP-MOF nanoparticles (NPs) exhibited promising antioxidant activity, as assessed by the DPPH assay. Furthermore, they showed more potent anti-inflammatory effects in LPS-induced BV2 microglial cells and superior anticancer activity against HepG2 and Caco-2 cell lines, as determined by the MTT assay and flow cytometry, compared to free CWP. Additionally, the CWP-MOF-NPs exhibited enhanced antimicrobial properties and increased efficacy as an anti-biofilm agent against pathogenic bacteria.

RevDate: 2025-06-07
CmpDate: 2025-06-05

Nilsson DPG, Wiklund K, Malyshev D, et al (2025)

3D-printed temperature and shear stress-controlled rocker platform for enhanced biofilm incubation.

Scientific reports, 15(1):19575.

Growing biofilms of thermophilic (heat-loving) and psychrotrophic (cold-tolerant) bacteria pose several challenges due to specific environmental requirements. Thermophilic bacteria typically grow between 45 and 80 [Formula: see text]C, while psychrotrophic bacteria thrive between 0 and 15 [Formula: see text]C. Maintaining the precise temperature and fluid conditions required for biofilm growth can be technically challenging. To overcome these challenges, we designed the Bio-Rocker, a temperature- and shear stress-controlled rocker platform for biofilm incubation. The platform supports temperatures between - 9 and 99 [Formula: see text]C, while its digital controller can adjust the rocking speed from 1 to 99[Formula: see text]/s and set rocking angles up to ±19[Formula: see text]. This ability, together with data from analytical models and multi-physics simulations, provides control over the shear stress distribution at the growth surfaces, peaking at 2.4 N/m[Formula: see text]. Finally, we evaluated the system's ability to grow bacteria at different temperatures, shear stress, and materials by looking at the coverage and thickness of the biofilm, as well as the total biomass. A step-by-step guide, 3D CAD files, and controller software is provided for easy replication of the Bio-Rocker, using mostly 3D-printed and off-the-shelf components. We conclude that the Bio-Rocker's performance is comparable to high-end commercial systems like the Enviro-Genie (Scientific Industries) yet costs less than $350 dollars to produce.

RevDate: 2025-06-04
CmpDate: 2025-06-04

Li Y, Liu Y, Zheng B, et al (2025)

Multicellular behavior and genomic characterization of Salmonella Typhimurium in animal-derived food chains in Xinjiang, China: Phenotypic resistance, biofilm formation, and sequence types.

Food research international (Ottawa, Ont.), 214:116698.

Salmonella Typhimurium Is a globally significant foodborne pathogen that causes diseases in livestock and poultry, which can lead to human infections and fatalities through contaminated food. In this study, we investigated the prevalence of Salmonella Typhimurium in the animal-derived food chain in Xinjiang, China. Among 5075 samples, the detection rate of Salmonella was 8.26 % (419/5075). Of these isolates, 27.21 % (114/419) were identified as Salmonella Typhimurium. Phenotypic analysis revealed significant antibiotic resistance: 82.46 % (94/114) of the strains exhibited multidrug resistance (MDR), with high resistance rates to amoxicillin / clavulanic acid, ampicillin, and tetracycline. Congo red plate assays demonstrated that 62.28 % (71/114) of the strains exhibited multicellular behavior (RDAR morphotype). Biofilm formation assays indicated that 96.49 % (110/114) of the strains possessed biofilm-forming capabilities, with 18.18 % (20/110) showing strong biofilm formation. Notably, strains displaying multicellular behavior exhibited enhanced biofilm formation, and biofilm capability was positively correlated with antibiotic resistance phenotypes. Whole-genome sequencing of 40 representative strains identified four sequence types (ST19, ST34, ST99, ST128), with ST34 being the most predominant. Distinct host preferences were observed: ST34 strains originated exclusively from cattle and sheep, while ST19, ST99, and ST128 strains were isolated from geese and pigeons. Resistance gene profiling revealed that strains harboring resistance genes exhibited stronger resistance phenotypes, while ST99 and ST128 strains lacked detectable resistance genes. Plasmids R64, R478, and pKPC_CAV1321 were identified in cattle- and sheep-derived strains, whereas pSLT-BT and pSPCV plasmids were predicted in strains from geese and pigeons. Pan-genome analysis and phylogenetic reconstruction demonstrated distinct genetic clustering among ST types, with ST19 and ST128 showing closer evolutionary relationships. This study provides comprehensive insights into the prevalence, phenotypic characteristics, and genomic diversity of Salmonella Typhimurium in the animal-derived food chain in Xinjiang. Our findings contribute to region-specific pathogen control strategies, enhancing public health safety and consumer protection.

RevDate: 2025-06-08
CmpDate: 2025-06-04

Sanches CVG, Terada RSS, Ramos AL, et al (2025)

In vitro evaluation of biofilm formation by Streptococcus mutans and Candida albicans in orthodontic aligners.

Dental press journal of orthodontics, 30(2):e2524192.

INTRODUCTION: Aligners have been used by the orthodontic community for approximately 20 years, but little research has been carried out on the accumulation of biofilm on the surface of these aligners, as well as their possible impact on the oral ecosystem.

METHODS: Ten hemi-arches of Invisalign® brand orthodontic aligners were used. The hemi-arches were placed inside sterile flasks containing 25 mL of Gibbons and Nygaard broth, with standardized suspensions of the two microorganisms on the 0.5 MacFarland scale and incubated in aerophily (C. albicans) and microaerophily (S. mutans and mixed biofilm) at 37°C for 72h. The biofilm formed was removed by the multiple rinses method to quantify the microorganisms in the biofilms in CFU/mL. A qualitative analysis with scanning electron microscopy was performed to observe the structure of the formed biofilms.

RESULTS: It was observed the accumulation of a monospecies biofilm (S. mutans - 2.55 x 106 and C. albicans - 1.62 x 107) and mixed biofilm (S. mutans - 2.21 x 105 and C. albicans - 1.06 x 107) very robust on the surface of orthodontic aligners.

CONCLUSION: According to the results obtained, one can conclude that Invisalign® brand orthodontic aligners are susceptible to the accumulation of monospecies and mixed biofilms of S. mutans and C. albicans. Therefore, it is necessary to consider the possibility of Invisalign® users developing carious lesions associated with the biofilm formed by these two microbial species, and to guide the patient on the correct cleaning of the device during treatment.

RevDate: 2025-06-04

Wang L, Fu H, Zhao J, et al (2025)

Cascade Magnetic Hyperthermia Therapy for Biofilm Eradication and Bone Regeneration via Dual Osteoimmuno-regulation.

ACS nano [Epub ahead of print].

Infected bone defects (IBDs) treatment presents a great challenge in current orthopedics due to the complex nature of these defects, and the diversified demands involving infection control and subsequent bone regeneration. Current-available treatments often fail to address these multifaceted needs effectively. Herein, we propose a cascade magnetic hyperthermia therapy (cMHT) strategy using MNP-PEI-siCkip-1 (MPSC), a magnetogenetic nanoplatform constructed by coating siRNA for casein kinase-2 interacting protein-1 (siCkip-1) and polyethylenimine-carboxylic acid (PEI-COOH) on ZnCoFe2O4@ZnMnFe2O4 nanoparticles. These MPSCs were then embedded in gelatin methacryloyl (GelMA) to form a nanocatalytic nanoparticle-hydrogel composite (MSG), which exhibited a strong magnetothermal effect. During the disinfection period, the MSG hydrogel generates MHT (∼50 °C) under alternative magnetic field (AMF) to destroy dense biofilm, and catalytically produce hydroxyl radicals (•OH) in biofilm microenvironment (BME) for anti-infection. Increased •OH production also promotes the proinflammation regulation of innate immunity for bacteria eradication. After the infection elimination, AMF was tuned to induce mild MHT (∼41 °C, mMHT) to promote osteogenesis and suppress excessive inflammation. Gradual MSG hydrogels degradation releases MPSCs, delivering siCkip-1 possessing osteogenic and anti-inflammatory activities to osteoblasts and macrophages. This cascade magnetic hyperthermia therapy (cMHT) strategy offers a compelling solution to the multifaceted challenges of IBD treatment, addressing critical aspects such as infection control and bone regeneration. The innovative approach underscores a promising potential of cMHT as transformative therapeutic option for IBDs, which may lead to improved treatment outcomes.

RevDate: 2025-06-04
CmpDate: 2025-06-04

Scott E, C Burkhart (2025)

A Review of the Role of C. Acnes and its Biofilm in Dandruff Pathogenesis.

Journal of drugs in dermatology : JDD, 24(6):566-569.

Dandruff is a common skin condition affecting up to half of the world's population. Symptoms include pruritus, inflammation, and flaking. It is thought to be in part due to microbe dysbiosis. This paper aims to discuss the relationship between dandruff and Cutibacterium acnes (C. acnes). It will also explore the potential role of C. acnes's biofilm in the formation of the biological glue that sticks dandruff flakes together. Citation: Scott E, Burkhart C. A review of the role of Cutibacterium acnes and its biofilm in dandruff pathogenesis. J Drugs Dermatol. 2025;24(6):566-569. doi:10.36849/JDD.8648R1.

RevDate: 2025-06-04

Florenço AMA, de Moura SST, Dos Santos Medeiros SMFR, et al (2025)

β-Lapachone encapsulated into stealth liposomes: inhibition of biofilm and cell wall thickness of MRSA.

Brazilian journal of microbiology : [publication of the Brazilian Society for Microbiology] [Epub ahead of print].

RevDate: 2025-06-03

Zheng Z, Lyu H, Wang L, et al (2025)

Microplastic biofilm may shape microbial community enriched with antibiotic resistance genes to enhance nitrogen transformation under antibiotic stress.

Journal of hazardous materials, 494:138796 pii:S0304-3894(25)01712-1 [Epub ahead of print].

The response of nitrogen transformation to microplastic biofilm under antibiotics (ATs) stress as well as the interrelationships between functional genes and microorganisms in surface water are not very well understood and need further investigation. This study investigated the response of nitrogen transformation by analyzing changes in various nitrogen forms and explored the interaction between nitrogen transformation functions and antibiotic resistance genes (ARGs) under exposure to ATs (ciprofloxacin (CIP) and tetracycline (TC)) and PVC biofilm. Compared to the control, exposure to mature polyvinyl chloride (PVC) biofilm increased nitrate nitrogen (NO3[-]-N) and ammonia nitrogen (NH4[+]-N) removal by 12.48 % and 8.79 %, with the NO3[-]-N removal rate constant reaching 0.17. However, co-exposure to CIP significantly inhibited nitrogen transformation, reducing the NO3[-]-N removal rate constant to 0.08. In PVC biofilm, more active nitrogen transformation and enhanced horizontal transfer of ARGs led to a stronger positive correlation between nitrogen transformation genes (NTGs) and ARGs. Microorganisms carrying NTGs largely overlapped with ARGs host species, including Hydrogenophaga, Rhodococcus, and Ignavibacterium, which exhibited high abundance of both gene types. This indicated that PVC biofilm facilitated nitrogen transformation under ATs stress by enriching nitrogen transformation microorganisms carrying high ARGs abundance. These results extended knowledge of effects of ATs and microplastics (MPs) on nitrogen transformation in surface water and provided theoretical support for unique ecological effects of microplastic biofilm.

RevDate: 2025-06-03

Lormand JD, Savelle CH, Teschler JK, et al (2025)

Secreted retropepsin-like enzymes are essential for stress tolerance and biofilm formation in Pseudomonas aeruginosa.

mBio [Epub ahead of print].

Proteases regulate important biological functions. Here, we present the structural and functional characterization of three previously uncharacterized aspartic proteases in Pseudomonas aeruginosa. We show that these proteases have structural hallmarks of retropepsin peptidases and play redundant roles for cell survival under hypoosmotic stress conditions. Consequently, we named them retropepsin-like osmotic stress tolerance peptidases (Rlo). Our research shows that while Rlo proteases are homologous to RimB, an aspartic peptidase involved in rhizosphere colonization and plant infection, they contain N-terminal signal peptides and perform distinct biological functions. Mutants lacking all three secreted Rlo peptidases show defects in antibiotic resistance, biofilm formation, and cell morphology. These defects are rescued by mutations in the inactive transglutaminase transmembrane protein RloB and the cytoplasmic ATP-grasp protein RloC, two previously uncharacterized genes in the same operon as one of the Rlo proteases. These studies identify Rlo proteases and rlo operon products as critical factors in clinically relevant processes, making them appealing targets for therapeutic strategies against Pseudomonas infections.IMPORTANCEBacterial infections have become harder to treat due to the ability of pathogens to adapt to different environments and the rise of antimicrobial resistance. This has led to longer illnesses, increased medical costs, and higher mortality rates. The opportunistic pathogen Pseudomonas aeruginosa is particularly problematic because of its inherent resistance to many antibiotics and its capacity to form biofilms, structures that allow bacteria to withstand hostile conditions. Our study uncovers a new class of retropepsin-like proteases in P. aeruginosa that are required for biofilm formation and bacterial survival under stress conditions, including antibiotic exposure. By identifying critical factors that determine bacterial fitness and adaptability, our research lays the foundation for developing new therapeutic strategies against bacterial infections.

RevDate: 2025-06-03

Pandey NK, Alkhatib AEA, S Hazra (2025)

Draft genome sequence of biofilm-forming Pseudomonas aeruginosa HLHR and non-biofilm-producing Pseudomonas sp. HLMP isolated from vermicompost.

Microbiology resource announcements [Epub ahead of print].

We announce the draft genomes of Pseudomonas aeruginosa HLHR and Pseudomonas sp. HLMP isolated from a vermicompost sample.

RevDate: 2025-06-03

Agustín MDR, Genovese DB, Palencia Díaz MA, et al (2025)

Efficacy of natamycin to reduce adhesion and biofilm formation of multispecies yeast biofilms on variable flow conditions.

Biofouling [Epub ahead of print].

This study evaluated the effectiveness of natamycin (NAT) on multispecies yeast biofilms isolated from ultrafiltration membranes in an apple juice processing industry. Biofilms were developed on stainless steel surfaces using 12° Brix apple juice under static (SC) and laminar flow (LF) conditions. NAT (0.01 mM) was applied from the beginning of the adhesion stage (NAT T0) and on 24-h-preformed biofilms (NAT T24). NAT T0 significantly reduced attachment and biofilm formation by ∼4-log10 units after 48 h, while NAT T24 achieved reductions of 1.83 and 0.79-log10 units in SC and LF, respectively. The overall reduction in total cell count was significantly more pronounced and consistent under SC. This highlights the importance of preventing initial adhesion for controlling biofilm development. Additionally, these findings underscore the importance of evaluating antimicrobial agents in dynamic flow conditions that closely mimic real-world applications.

RevDate: 2025-06-03

Yu L, Xu L, Zhao Y, et al (2025)

The role of YbdO in regulating acid resistance and biofilm formation in avian pathogenic Escherichia coli.

Avian pathology : journal of the W.V.P.A [Epub ahead of print].

Avian pathogenic Escherichia coli (APEC) causes severe systemic infectious diseases known as colibacillosis in avian species, resulting in significant economic losses to the poultry industry worldwide, and threatening food security and human health. Previous studies show that acid resistance is an indispensable mechanism that allows E. coli to survive in the gastrointestinal tract; and biofilm formation results in persistent and recurrent infections in the host, and is the main reason for the difficult treatment of colibacillosis with antimicrobial agents. In this study, we confirmed YbdO as a transcriptional regulator that increased biofilm formation by upregulating the transcription of the biofilm-associated genes bcsE, csgD, pgaA, wcaD, fimH, and flhD and acid resistance by activating the expression of acid stress chaperone HdeA and acid stress response protein YqgB in APEC CE1. Additionally, electrophoretic mobility shift assay (EMSA) indicated that YbdO directly activated the expression of CsgD, HdeA and YqgB by directly binding to the promoters of csgD, hdeA and yqgB, respectively. These findings demonstrate the regulatory mechanism of YbdO on acid resistance and biofilm formation and enhance our understanding of how APEC improves the adaptability to environmental stresses, thereby increasing the pathogenicity of APEC. Therefore, this study might provide a paradigm for the regulation of biofilm formation and acid resistance that can be used to study other bacterial pathogens.

RevDate: 2025-06-03

van Dun SCJ, Knol R, Silva-Herdade AS, et al (2025)

Machine learning assisted classification of staphylococcal biofilm maturity.

Biofilm, 9:100283.

An increasing incidence of device-related, biofilm-associated infections has been observed in clinical practice worldwide. In vitro biofilm models are essential to study these burdensome infections and to design and test potential new treatment approaches. However, there is considerable variation in in vitro biofilm models, and a generally accepted systematic description of biofilm maturity - apart from incubation time - is lacking. Therefore, we proposed a scheme comprised of 6 different classes based on common topographic characteristics, i.e., the substrate, bacterial cells and extracellular matrix, identified by atomic force microscopy (AFM), to describe biofilm maturity independent of incubation time. Evaluation of a test set of staphylococcal biofilm images by a group of independent researchers showed that human observers were capable of classifying images with a mean accuracy of 0.77 ± 0.18. However, manual evaluation of AFM biofilm images is time-consuming, and subject to observer bias. To circumvent these disadvantages, a machine learning algorithm was designed and developed to aid in classification of biofilm images. The designed algorithm was capable of identifying pre-set characteristics of biofilms and able to discriminate between the six different classes in the proposed framework. Compared to the established ground truth, the mean accuracy of the developed algorithm amounted to 0.66 ± 0.06 with comparable recall, and off-by-one accuracy of 0.91 ± 0.05. This algorithm, which classifies AFM images of biofilms, has been made available as an open access desktop tool.

RevDate: 2025-06-03
CmpDate: 2025-06-03

Kincses A, Ghazal TSA, Veres K, et al (2025)

Phenolic compounds from Origanum majorana with biofilm-inhibitory activity against methicillin-resistant Staphylococcus aureus and Escherichia coli strains.

Pharmaceutical biology, 63(1):402-410.

CONTEXT: Antibiotic resistance in bacteria is a growing global problem, with biofilm formation and efflux pumps playing crucial roles in this issue.

OBJECTIVE: This study explores the effects of phenolic compounds of Origanum majorana against Escherichia coli and methicillin-resistant Staphylococcus aureus (MRSA) strains by inhibiting biofilm formation and efflux pumps.

MATERIALS AND METHODS: The methanolic extract of O. majorana was fractionated guided by an antibiofilm assay, and the active fractions were analyzed by multistep chromatographic separation to yield five pure compounds. Their structures were then determined using 1D and 2D nuclear magnetic resonance spectroscopy. The minimum inhibitory concentrations of the extracts, fractions, and isolated compounds were determined via the microdilution method in a 96-well plate. Antibiofilm activity was assessed using the crystal violet method, and the effect on efflux pumps was tested by a real-time ethidium bromide accumulation assay.

RESULTS: Arbutin (1), apigenin 7-O-glucoside (2), 6'-caffeoylarbutin (3), rosmarinic acid (4), and 2-deoxy-d-1,4-ribonolactone (5) were isolated from the aqueous methanolic extract. Compounds 1, 2, and 4 reduced E. coli biofilm formation by 24.82%-42.98% at 100 µM, whereas only arbutin (1) moderately suppressed biofilm formation of MRSA (23.15 ± 1.56% at 50 µM). Arbutin also demonstrated efflux pump inhibitory activity against MRSA (relative fluorescence index of 0.49 at 100 µM).

DISCUSSION AND CONCLUSIONS: The newly discovered natural antibiofilm agents show promise as candidates for treating biofilm-associated infections and combating antibiotic-resistant bacteria.

RevDate: 2025-06-03

Long X, He Y, Wang A, et al (2025)

Lysozyme Fiber-Inspired Versatile Supramolecular Hydrogel Against Drug-Resistant Pathogens and Biofilm Formation.

Advanced healthcare materials [Epub ahead of print].

Multidrug-resistant (MDR) bacterial infections pose a significant threat to human health, particularly when introduced by surgical contamination, resulting in early-stage implant-related biofilm infections and potential implant failure. Inspired by the structure and function of lysozyme fibers, a biomimetic supramolecular hydrogel is developed that mimics the lysozyme fiber architecture and encapsulates D-tyrosine (D-Tyr), integrating bactericidal and anti-biofilm functions within a self-assembled positively charged nanofibrous network. The peptide backbone with quaternary ammonium salt-modified fibers disrupts bacterial cell membranes through direct contact, thereby damaging structural integrity, causing cytoplasmic leakage and killing bacteria; meanwhile, D-Tyr's effective sustained release inhibits initial bacterial contamination and prevents subsequent biofilm formation. In vivo, experiments demonstrated that the hydrogel significantly accelerated the healing of Methicillin-resistant Staphylococcus aureus (MRSA)-infected skin abscesses and prevented implant-related biofilm infections during the preliminary stages of implantation. By exploiting synergistic bactericidal and anti-biofilm effects, this lysozyme fiber-inspired hydrogel offers a promising strategy to combat MDR bacterial infections and prevent biofilm-related implant complications.

RevDate: 2025-06-04

Shrestha P, Kim B, Han SR, et al (2025)

Unraveling the genetic mechanisms of UV radiation resistance in Bacillus through biofilm formation, sporulation, and carotenoid production.

Genomics, 117(4):111066 pii:S0888-7543(25)00082-5 [Epub ahead of print].

Bacillus species are Gram-positive bacteria that are rod-shaped, endospore-forming, and aerobic or facultatively anaerobic. With over 300 recognized species, Bacillus subtilis stands out as a well-studied model organism. The genus's various species exhibit a wide range of physiological capabilities, allowing them to thrive in diverse environmental conditions. Each cell produces a single endospore, which is highly resistant to heat, cold, radiation, desiccation, and disinfectants. Among Bacillus strains, those capable of producing spores, biofilms, and carotenoids demonstrate significant resilience to UV light. This review examines the genes involved in spore formation, biofilm development, and carotenoid synthesis, emphasizing their roles in UV radiation survival. We explore the interconnections between these processes and their combined contribution to UV resistance, focusing on the underlying genetic mechanisms. These insights will benefit researchers studying the genetic basis of UV radiation resistance in Bacillus species. IMPORTANCE: Bacteria employ adaptive strategies in extreme environments through rapid changes in gene expression, altering their phenotype for survival. Bacillus species, for example, defend against UV radiation by making spores, creating biofilms, and producing pigments. During sporulation, sigma factors (σ[F], σ[E], σ[G], and σ[K]) regulate gene expression to adapt to environmental shifts. It has been found that the spores of some species may contain pigments that strongly absorb UV radiation, playing a crucial role in spore UV resistance. UV light penetrates biofilm matrices minimally, mainly affecting surface cells, which produce compounds like mycosporine-like amino acids and carotenoids to shield against UV damage.

RevDate: 2025-06-02

Stabile Gouveia J, Paula Castro V, Rossi F, et al (2025)

Quantifying biofilm matrix components: effects of chlorhexidine and orthophthalaldehyde on Candida parapsilosis and Staphylococcus aureus.

Biofouling [Epub ahead of print].

Candida and Staphylococcus species are responsible for hospital-acquired infections, forming resilient biofilms. This study evaluated the impact of biocides on the biofilm matrix components of Candida parapsilosis and Staphylococcus aureus in monospecies and mixed biofilms. Proteins, carbohydrates, and extracellular DNA (eDNA) were quantified using the Bradford reagent, phenol-sulfuric acid, and silica column extraction with spectrophotometric readings at 260 and 280 nm. Biofilms were treated with 0.5% chlorhexidine (CLX) and 0.55% ortho-phthalaldehyde (OPA) for 3 and 10 min, respectively. Results showed a significant protein increase (8.6 ± 4.94 µg/mL for C. parapsilosis and 17.25 ± 1.86 µg/mL for S. aureus) after CLX and OPA exposure, especially in isolates 935 M, 936 C, and S. aureus biofilms (p < 0.01). Carbohydrates significantly decreased (p < 0.0001), with CLX generally more effective than OPA. eDNA levels increased across all samples. These findings suggest that CLX and OPA alter biofilm matrix composition, facilitating antimicrobial efficacy.

RevDate: 2025-06-02

Liu Y, Gates AD, Liu Z, et al (2025)

In vitro biofilm formation by a beneficial bacterium partially predicts in planta protection against rhizosphere pathogens.

The ISME journal pii:8154967 [Epub ahead of print].

Plant roots form associations with beneficial and pathogenic soil microorganisms. Although members of the rhizosphere microbiome can protect against pathogens, the mechanisms are poorly understood. We hypothesized that the ability to form a biofilm on the root surface is necessary for the exclusion of pathogens; however, it is not known if the same biofilm formation components required in vitro are necessary in vivo. Pseudomonas brassicacearum WCS365 is a beneficial strain that is phylogenetically closely related to an opportunistic pathogen Pseudomonas sp. N2C3 and confers protection against N2C3 in the rhizosphere. We used this plant-mutualist-pathogen model to screen collections of P. brassicacearum WCS365 increased attachment mutants (iam) and surface attachment defective (sad) transposon insertion mutants that form increased or decreased biofilm on abiotic surfaces, respectively. We found that whereas the P. brassicacearum WCS365 mutants had altered biofilm formation in vitro, only a subset of these mutants lost protection against N2C3. Non-protective mutants those involved in large adhesion protein (LapA) biosynthesis, flagellar synthesis and function, and O-antigen biosynthesis. We found that the inability of P. brassicacearum WCS365 mutants to grow in planta, and the inability to suppress pathogen growth, both partially contributed to loss of plant protection. We did not find a correlation between the extent of biofilm formed in vitro and pathogen protection in planta indicating that biofilm formation on abiotic surfaces may not fully predict pathogen exclusion in planta. Collectively, our work provides insights into mechanisms of biofilm formation and host colonization that shape the outcomes of host-microbe-pathogen interactions.

RevDate: 2025-06-03

Zhang Z, Xu C, Y Bai (2025)

Effect of autoinducer-2 on biofilm formation of mixed strains derived from kefir.

Food chemistry: X, 27:102490.

The mechanisms underlying kefir grain formation remain to be elucidated. Quorum sensing is a new direction for investigating this process. To explore the formation mechanism of kefir grain through quorum sensing, it is first necessary to establish its association with kefir grain formation. As biofilm constitutes the foundation of the extracellular matrix in kefir grains, this study focused on its relationship with quorum sensing. Three lactic acid bacteria, one yeast, and one acetic acid bacteria with strong biofilm-forming abilities were isolated from kefir and were cultured in pairwise and three-strain mixed cultures. The results revealed a strong correlation between autoinducer-2 secretion and biofilm formation, with both displaying similar trends under various culture conditions. Optimal biofilm formation and autoinducer-2 production were observed at 4 h, 37 °C, and pH 7.5. Under these conditions, the three-strain mixed culture exhibited the highest autoinducer-2 fluorescence intensity (6.45 ± 0.27), and biofilm quantity reached 3.83 ± 0.094. Notably, biofilm formation and autoinducer-2 secretion were lower in the same-strain cultures than in the mixed-strain cultures. This study is the first to establish a strong link between quorum sensing and kefir grain formation.

RevDate: 2025-06-03

Cheng X, Yang Z, Ji K, et al (2025)

Enhanced copper adsorption by polyamide and polylactic acid microplastics: The role of biofilm development and chemical aging.

Environmental research, 282:122040 pii:S0013-9351(25)01291-5 [Epub ahead of print].

Plastics undergo a range of physical, chemical, and biological changes in natural aquatic environments, which profoundly affect their environmental fate and bioavailability. This study investigates the effects of potassium persulfate (K2S2O8) oxidation and biofilm attachment on the surface p'roperties and Cu(II) adsorption behavior of polyamide (PA) and polylactic acid (PLA) microplastics. Both chemical aging and biofilm formation significantly increase the specific surface area, crystallinity, and oxygen-containing functional groups of these microplastics. Specifically, the specific surface area of K2S2O8-aged PA and PLA microplastics increased to 3.546 m[2] g[-1] and 2.930 m[2] g[-1], respectively. 16S rDNA analysis revealed distinct bacterial communities on PA and PLA-MPs, reflecting different microbial attachment due to polymer types. Compared to pristine microplastics, K2S2O8-aged PA and biofilm-covered PA had Cu(II) adsorption capacities of 1.536 mg g[-1] and 0.946 mg g[-1], respectively, while K2S2O8-aged PLA and biofilm-covered PLA capacities increased to 1.163 mg g[-1] and 0.812 mg g[-1]. Cu(II) adsorption onto aged microplastics followed the Freundlich model, indicating a multilayer adsorption mechanism. The pH significantly impacted Cu(II) adsorption efficiency, with the best performance observed under near-neutral conditions. Fulvic acid inhibited Cu(II) adsorption by competing for adsorption sites and forming complexes with Cu(II). These findings highlight the transformation mechanisms of microplastics within natural settings and their potential as heavy metal carriers, providing vital insights for assessing the environmental impact of microplastic pollution.

RevDate: 2025-06-01
CmpDate: 2025-06-01

Aniba R, Dihmane A, Raqraq H, et al (2025)

Phenotypic and molecular characterization of biofilm formation, antibiotic resistance, and disinfectant tolerance in Staphylococcus saprophyticus isolated from urinary tract infections.

World journal of urology, 43(1):346.

PURPOSE: This study investigates the phenotypic and genotypic characteristics of Staphylococcus saprophyticus isolates from urinary tract infections (UTIs), focusing on antibiotic resistance, biofilm formation, and disinfectant susceptibility.

METHODS: Antimicrobial susceptibility was assessed using the disk diffusion method, while biofilm formation was quantified via the microtiter plate assay. The minimum inhibitory and minimum bactericidal concentrations of four hospital disinfectants were determined using broth microdilution, and their antibiofilm efficacy was evaluated using the crystal violet assay. Antibiotics resistance and biofilm-associated genes were detected by polymerase chain reaction.

RESULTS: Among the isolates, 50% were multidrug-resistant, 10.86% carried the mecA gene and were classified as methicillin-resistant S. saprophyticus, and 89.1% exhibited biofilm formation, with 43.9% classified as moderate biofilm producers. Sodium hypochlorite (2.6%) and a benzalkonium chloride (10%)-glutaraldehyde (5%) mixture demonstrated the highest antimicrobial efficacy, while hydrogen peroxide (3%) exhibited the weakest antibacterial effect. Biofilm inhibition and eradication were most effective with sodium hypochlorite (2.6%) and hydrogen peroxide (3%), whereas benzalkonium chloride-glutaraldehyde mixture showed the least antibiofilm activity. The qacA/B gene, associated with disinfectant resistance, was detected in 28.27% of isolates, while qacC was present in 6.66%. Notably, subinhibitory disinfectant concentrations stimulated biofilm formation, potentially enhancing bacterial persistence in healthcare environments.

CONCLUSIONS: These findings highlight the dual challenge posed by S. saprophyticus UTIs, where antibiotic resistance and biofilm formation contribute to treatment difficulties. The inappropriate use of disinfectants may select for resistant strains, emphasizing the need for evidence-based disinfection protocols to prevent bacterial persistence in clinical settings.

RevDate: 2025-06-01

Wani PA, Wani TA, Oluwagbemisola OO, et al (2025)

Corrigendum to "Green synthesized antimicrobial peptides and nanoparticles from Phoenix dactylifera: Evaluation of anti-biofilm, anti-pathogenic and anti-diabetic activities" [Microbial Pathog. 205 (2025) 107700].

RevDate: 2025-06-03

Baninajarian H, Tahmourespour A, Vedaei A, et al (2025)

Evaluation of the effect of different infant formulas on Streptococcus mutans biofilm formation: an in-vitro study.

The Saudi dental journal, 37(4-6):10.

Considering the increase in the prevalence of early childhood caries, the effect of various types of frequently consumed infant milk formulas on the development of Streptococcus mutans biofilm was examined. Three samples of cow's milk-based formula (Aptamil, Bebelac, Nan), two samples of soy-based formula (Biomil soy and Isomil soy), and three samples of formulas containing hydrolyzed proteins (Aptamil HA, Bebelac HA, Nan HA) were selected. After adding the formulas to the Streptococcus mutans (ATCC 35668) culture media, the degree of bacterial biofilm formation was explored by assessing the optical density (OD) of the Cristal Violet dye in the decolorizing solution using an ELISA reader device. The analysis of the data was conducted using independent sample T-tests, ANOVA, and subsequently Fisher's LSD test using SPSS 22 software. A statistically significant difference was observed in the average levels of biofilm formation of Streptococcus mutans for the three types of understudy formulas (P < 0.001). In the presence of cow's milk-based formulas, the mean amount of biofilm formation was significantly greater than that of the soy-based (P = 0.003) and protein hydrolysate (P < 0.0001) formulas. However, no significant statistical difference was detected between the soy-based and protein hydrolysate formulas (P = 0.42). Aptamil exhibited the highest amount of biofilm formation with a mean OD of 1.81 whereas Aptamil HA showed the lowest amount of biofilm formation (OD = 0.61). The level of biofilm formation by Streptococcus mutans when exposed to cow's milk-based formula was noted to be greater than that observed with the soy-based and protein hydrolysate formulas.

RevDate: 2025-06-01

Tuan DA (2025)

Comparative antifungal efficacy of trans-cinnamaldehyde and nystatin against biofilm-forming Candida Species: Structural insights and drug susceptibility.

Microbial pathogenesis, 206:107763 pii:S0882-4010(25)00488-7 [Epub ahead of print].

Biofilm-associated infections caused by Candida species present significant therapeutic challenges due to their resistance to conventional antifungal agents. This study compared the antifungal efficacy of trans-Cinnamaldehyde-a natural compound extracted and purified from Cinnamon Tra My (Vietnam)-with nystatin against Candida albicans, C. glabrata, and C. tropicalis in both planktonic and biofilm forms. Planktonic Minimum Inhibitory Concentration (PMIC) and Minimum Biofilm Inhibitory Concentration (MBIC) values were determined using the CLSI M27-A3 protocol and MTT assay, while biofilm structure was assessed via light microscopy. Nystatin demonstrated superior efficacy across all species, with MBIC100 values of 0.008 mg/mL for C. albicans and C. glabrata, and 0.032 mg/mL for C. tropicalis. In contrast, trans-Cinnamaldehyde required 0.32 mg/mL to achieve MBIC100 in C. albicans and C. glabrata, and 0.63 mg/mL in C. tropicalis. Microscopic analysis confirmed pronounced biofilm disruption in C. albicans post-treatment with trans-Cinnamaldehyde, whereas C. tropicalis biofilms remained structurally resilient. These findings highlight the species-dependent susceptibility of Candida biofilms and underscore nystatin's continued role as a frontline antifungal. Trans-Cinnamaldehyde, while less potent, shows promise as a natural adjunct, particularly against C. albicans and C. glabrata biofilms.

RevDate: 2025-05-31

Zheng Z, Gustavsson DJI, Zheng D, et al (2025)

Genome-centric metagenomics reveals the effect of organic carbon source on one-stage partial denitrification-anammox in biofilm reactors.

Journal of environmental management, 388:125972 pii:S0301-4797(25)01948-6 [Epub ahead of print].

Nitrogen removal from wastewater with anammox saves energy and resources. Partial denitrification-anammox (PDA) is a promising process alternative for municipal wastewater treatment, given that the understanding about how to control the microbiome and its activity reach sufficient level. Here, two moving bed biofilm reactors were fed with either acetate or propionate to study the role of organic carbon type for microbiome composition and nitrogen turnover during development of PDA. With acetate, 87 % of the removed nitrogen was converted via anammox during stable operation at a rate of 0.52 g N/(m[2]·d). With propionate, the anammox contribution was considerably lower (41 %), as was the rate of nitrogen removal (0.27 g N/(m[2]·d)). The microbiome composition in the acetate- and propionate-fed reactors was however similar, with an enrichment of metagenome assembled genomes (MAGs) having genes for nitrate reduction (narG, napA). A large fraction of these MAGs had the potential to accumulate nitrite since they lacked genes for nitrite reduction (nirS, nirK, nrfA). Genes for acetate utilization were common among these MAGs, but the necessary genes for propionate conversion were rare, suggesting that the genetic make-up of the individual denitrifiers had major influence on the nitrogen turnover. One anammox MAG (Ca. Brocadia sapporoensis), harboring genes for organic carbon utilization, prevailed in the PDA reactors. Another three anammox MAGs (Ca. B. fulgida, Ca. B. pituitae and a potentially new species within Ca. Brocadia), lacking genes for organic carbon utilization, decreased in abundance in the reactors, indicating the importance of metabolic versatility for anammox bacteria in PDA.

RevDate: 2025-05-31

Xia Z, Ng HY, S Bae (2025)

Synergistic microalgal-bacterial interactions enhance nitrogen removal in membrane-aerated biofilm photoreactors treating aquaculture wastewater under salt stress: Insights from metagenomic analysis.

Water research, 283:123878 pii:S0043-1354(25)00786-9 [Epub ahead of print].

This study investigates the membrane-aerated biofilm photoreactor (MABPR) for treating aquaculture effluents with low C/N ratio and elevated salinity (0.5%-3.2%). The MABPR integrated biofilm reactors with microalgal-bacterial consortia, achieving superior total inorganic nitrogen (TIN) removal by leveraging counter-diffusional biofilm properties, bubbleless aeration, and enhanced microalgal productivity. The system consistently outperformed conventional reactors, achieving 84.7 ± 1.9% TIN removal at 3.2% salinity with TIN removal flux increasing from 0.82 ± 0.04 to 1.22 ± 0.07 g/m[2] d. The MABPR promoted microalgal proliferation (Chl-a/VSS: 8.08-15.04 mg/g) and higher biomass productivity (1.83 g/m[2] d) compared to SBBPR and MABR. Elevated salinity stimulated extracellular polymeric substance (EPS) production, reinforcing biofilm stability and microbial resilience. The MABPR demonstrated 22%-65% higher nitrogen removal efficiency than controls at the highest salinity. Canonical nitrification-denitrification remained the primary nitrogen removal pathway, with short-cut nitrification-denitrification contributing under salt stress. Metagenomic analysis revealed bidirectional adaptation between microalgae and bacteria, with enriched nitrogen assimilation (GS/GOGAT pathway) compensating for bacterial deficits. Microalgae facilitated pollutant removal through ammonia uptake and dissolved organic matter release, supporting denitrification. At 3.2% salinity, Nitrosomonas and Nitrobacter abundance increased by 42.6% and 35.8%, while denitrifiers Denitromonas and Hoeflea dominated, comprising 59.4% and 35.9% of the population. The MABPR further promoted the synthesis of growth cofactors (vitamins, phytohormones), enhancing microalgal productivity and stress resilience. These synergistic microalgal-bacterial interactions supported pollutant removal, showcasing the MABPR as a robust, sustainable solution for aquaculture wastewater treatment and resource recovery under salt stress.

RevDate: 2025-06-02
CmpDate: 2025-05-30

Pérez-Padilla V, Molina-Henares MA, Udaondo Z, et al (2025)

Genetic basis of biofilm formation and salt adaptation in the plant-beneficial strain Stutzerimonas stutzeri MJL19.

Applied microbiology and biotechnology, 109(1):130.

Stutzerimonas stutzeri MJL19 represents a potential candidate for agrobiotechnological applications in regions affected by soil salinization, given its protective effects on plants under saline stress. This strain forms biofilms on some abiotic surfaces and on plant roots, a trait that influences the colonization and persistence capacities of bacteria in the rhizosphere. However, the mechanistic basis for the multicellular lifestyle of S. stutzeri MJL19 and its connection with the adaptation to saline conditions had not been explored. Analysis of the genome of MJL19 has allowed the identification of two gene clusters involved in the synthesis of exopolysaccharides (cellulose and a species-specific polymer). Deletion of either or both gene clusters exposed their differential roles on abiotic and biotic surfaces and phenotypic changes in response to increasing salt concentrations. Expression of both clusters is regulated by the two-component system GacS/GacA, as evidenced by analysis of a gacS mutant obtained by random transposon mutagenesis. This mutant also shows altered levels of the intracellular second messenger cyclic diguanylate (c-di-GMP), which is key in the transition between free-living and sessile lifestyles. Results also suggest the existence of regulatory interconnections between exopolysaccharide synthesis genes, and of these with c-di-GMP turnover, which is in turn modulated by the presence of NaCl. GacS is required for this response to varying salt concentrations. We also describe two additional elements that influence c-di-GMP levels and the response to salt: the gene katE, encoding catalase HP-II, and a gene that encodes a protein of the lipoteichoic acid synthases family. KEY POINTS: • GacS controls c-di-GMP levels and EPS synthesis in S. stutzeri MJL19 in response to salt. • Regulation of EPS genes is interconnected and linked to c-di-GMP turnover. • The catalase KatE influences c-di-GMP levels.

RevDate: 2025-06-02
CmpDate: 2025-05-30

Mikolai C, Wöll K, Rahim MI, et al (2025)

Impact of antibacterial therapeutic agents on biofilm-tissue interactions in a 3D implant-tissue-oral-bacterial-biofilm model.

Scientific reports, 15(1):18979.

Bacterial biofilms on dental implants can lead to peri-implant infections and demonstrate a remarkable ability to evade host immunity and resist antibiotics. Advanced in vitro models, such as the three-dimensional implant-tissue-oral-bacterial-biofilm model (INTERbACT), are essential to evaluate antibiofilm efficacy. The INTERbACT model, effectively reproduces the complex triangular interactions between an organotypic oral mucosa, an integrated implant and an oral multispecies biofilms, in the peri-implant situation. Here, we investigated the effect of antibacterial agents (chlorhexidine, amoxicillin, ciprofloxacin, doxycycline, and metronidazole) on biofilm-tissue interactions in the INTERbACT model. While the antibacterial interventions had no effect on biofilm volume, all agents decreased the proportion of viable bacteria, underscoring their effect on bacterial viability despite biofilm resilience. Biofilm exposure to untreated tissues caused epithelial damage, whereas all antibacterial agents preserved epithelial integrity. However, the modulation of pro-inflammatory response differed between the various agents. All antibacterial treatments reduced hBD-2 and TIMP-1 levels. While doxycycline decreased IL-1β and CCL20, chlorhexidine lowered TNF-α level. In conclusion, the INTERbACT model allowed the successful assessment of antibacterial efficacy, elucidation of biofilm resistance and characterization of inflammation during peri-implant tissue-biofilm interactions. This validation highlights the model's potential as a platform for developing and evaluating new therapeutic strategies for peri-implant diseases.

RevDate: 2025-06-02
CmpDate: 2025-05-30

Upadhyay T, Woods EC, Dela Ahator S, et al (2025)

Identification of covalent inhibitors of Staphylococcus aureus serine hydrolases important for virulence and biofilm formation.

Nature communications, 16(1):5046.

Staphylococcus aureus is a leading cause of bacteria-associated mortality worldwide. New tools are needed to both image and treat this pathogen. We previously identified a group of S. aureus serine hydrolases (Fphs), which regulate aspects of virulence and lipid metabolism. However, due to high structural and functional similarities, it remains challenging to distinguish the specific roles of members of this family. Here, we apply a high-throughput screening approach using a library of covalent electrophiles to identify inhibitors for FphB, FphE, and FphH. We identify selective covalent inhibitors for each target without the need for extensive medicinal chemistry optimization. Structural and biochemical analysis identify novel binding modes for several of the inhibitors. Functional studies using the inhibitors suggest that all three hydrolases likely play distinct functional roles in biofilm formation and virulence. This approach has the potential to be applied to target hydrolases in other diverse pathogens or higher eukaryotes.

RevDate: 2025-05-30

Pereira ABV, Terroso MS, Gonçalves H, et al (2025)

Hybrid nano-scaffolds loaded with resveratrol and Omega-3 fatty Acids: An innovative antimicrobial strategy against biofilm.

International journal of pharmaceutics pii:S0378-5173(25)00621-0 [Epub ahead of print].

It is widely accepted that biofilms associated with body tissues are responsible for many antibiotic treatment failures and contribute to various chronic infections. Therefore, it is critical to create novel approaches to wound treatment. The development of nanocarriers to combat biofilms formation has been an area of much research in recent years. The main aim of this work was to develop hybrid nano-scaffolds composed by nanofibers and liposomes, i.e. large unilamellar vesicles (LUVs), loaded with resveratrol (RSV) and/or omega-3 fatty acids (ω3) and to evaluate their capacity to prevent biofilm formation. The studies carried out included the preparation and characterization of LUVs, evaluation of antibiofilm activity for Staphylococcus aureus and Escherichia coli, and cytotoxicity evaluation using fibroblasts. RSV and ω3 loaded LUVs were effective in inhibiting biofilms formation, resulting in an increased antibiofilm effect (almost 100 %) compared to free RSV and ω3 (65 % - 96.4 %). The biocompatibility of the LUVs was also confirmed (cell viability above 70 %), and a positive effect on cell proliferation (cell viability above 70 %) was observed after 7 days. The porous structure and random orientation of the produced nanofibers impregnated with LUVs enable the exchange of exudates, gases, and nutrients, while resembling the extracellular matrix of the skin, encouraging cell adhesion and proliferation. The nanofibers are characterized by adequate mechanical properties (elongation at break of 208 ± 9 % and young's modulus of 50.3 ± 0.3 MPa) and a high surface area to volume ratio, thus increasing the release profile of RSV (94.8 ± 2.6 % of RSV within 30 min), which is advantageous for anti-biofilm activity. The impregnation of nanofibers with LUVs loaded with RSV and/or ω3 may represent a promising approach for improving wound healing therapies, allowing the control of biofilm formation and even promoting skin regeneration.

RevDate: 2025-05-30

Bisen M, L Kumar (2025)

Veratraldehyde Inhibits Motility Phenotypes and Targets Biofilm Formation of Pseudomonas aeruginosa: Insights From Computational and Experimental Studies.

Chemistry & biodiversity [Epub ahead of print].

Pseudomonas aeruginosa, a versatile pathogen that poses significant challenges in healthcare and food industries due to its ability to form biofilms. The present study investigated the anti-biofilm properties of a natural compound, veratraldehyde (VD) against P. aeruginosa biofilms. Although VD exhibited weak antibacterial activity (minimum inhibitory concentration [MIC] > 512 µg/mL), it demonstrated potent motility inhibition at sub-inhibitory concentrations, with the highest inhibition observed in swimming (78.13%), twitching (70.96%), and swarming (56.74%) across various strains. Tube assay showed highest inhibition on Day 1 (32.73%) and Day 3 (15.58%) across various strains with VD. Detailed microscopic analysis (light, florescence, and scanning electron microscopy) clearly show that veratraldehyde effectively inhibits biofilm formation in multiple P. aeruginosa strains. In silico molecular docking and dynamic simulation studies suggest that veratraldehyde may target the PilY protein, a component of Type-IV pili involved in pilus biogenesis, potentially disrupting biofilm formation at a molecular level. In silico pharmacokinetic analysis such as absorption, distribution, metabolism, and excretion (ADME) analysis indicates favorable properties (e.g., bioavailability, solubility, drug likeness, high gastrointestinal (GI) absorption, and skin permeability), making veratraldehyde a promising candidate for anti-biofilm therapeutic development. These results highlight its potential as a natural alternative to conventional antibiotics in combating P. aeruginosa biofilm associated infections.

RevDate: 2025-05-30
CmpDate: 2025-05-30

Taylor DW, AD Jones (3rd) (2025)

Synthesis of Metal-Modified Nanocellulose as a Biofilm Analogue for Biofilm Mimicry in Biomedical and Environmental Applications.

Biopolymers, 116(4):e70029.

Bacterial biofilms are complex, multi-component structures consisting primarily of four key elements: polysaccharides, metal ions, proteins, and extracellular DNA. In our research, we specifically focus on the polysaccharide and metal ion components, which play a crucial role in determining the biofilm's mechanical properties. Polysaccharides provide the structural matrix, although metal ions, particularly divalent cations like calcium and cobalt, cross-link with the polysaccharides, thereby modulating the biofilm's rigidity and viscoelastic behavior. By introducing divalent cations into nanocellulose, we can replicate this natural cross-linking process, allowing us to finely tune the material's mechanical properties to more closely resemble those of bacterial biofilms. This approach not only enhances the accuracy of synthetic biofilm models over alginate hydrogels but also provides valuable insights into how biofilms maintain their structural integrity in various environments. Our findings indicate that nanocellulose exhibits mechanical properties closer to biofilms than alginate analogs, making it a suitable non-living control for biofilm studies. Furthermore, divalent nickel, followed by calcium and magnesium, demonstrate a closer mechanical mimicry to biofilms. In conclusion, this research shows the potential of nanocellulose as a versatile material for bacterial biofilm mimicry.

RevDate: 2025-05-30

Adhikary R, Sarkar I, Patel D, et al (2025)

De novo assembly of multidrug resistant biofilm forming Micrococcus luteus genome from hemodialysis tunneled cuffed catheter tips of patients undergoing renal failure treatment.

Microbiology resource announcements [Epub ahead of print].

Micrococcus luteus HL_Chru_C3 was isolated from the hemodialysis tunneled cuffed catheter tip of renal failure patients. Whole-genome sequencing (WGS) revealed a 2,494,573 bp genome with 12 contigs, 72% GC content, and 2,240 protein-coding genes. The computational prediction of penicillin-binding proteins and biofilm-forming signaling gene cassettes may contribute to the resistance mechanisms.

RevDate: 2025-05-30

Jin Y, Zhang Y, Xue C, et al (2025)

Phototriggered Biofilm Nanodisruptor with Genetic Modulation for Treating Drug-Resistant Bacterial Infections.

ACS applied materials & interfaces [Epub ahead of print].

Biofilm-associated bacterial infections pose significant therapeutic challenges due to their enhanced antibiotic resistance and complex extracellular matrix structure. To address this, we developed a carrier-free nanocomposite (named SPX-ICG) through self-assembling the antibiotic sparfloxacin (SPX) and the photosensitizer indocyanine green (ICG), creating a triple-mode antibacterial system that integrates photothermal, photodynamic, and antibiotic therapies. Upon near-infrared irradiation, SPX-ICG disassembled in the acidic biofilm environment, releasing bioactive components and initiating a therapeutic cascade: ICG generated mild photothermal effects that enhanced biofilm permeability, while simultaneously producing reactive oxygen species through photodynamic therapy, enabling efficient antibiotic penetration and bacterial eradication. The transcriptomic analysis revealed that SPX-ICG significantly downregulated genes involved in quorum sensing and two-component signal transduction systems, suggesting a fundamental reshaping of the biofilm microenvironment. Furthermore, SPX-ICG also demonstrated superior in vivo antibacterial effects in infected mouse models, effectively eradicating Staphylococcus aureus (S. aureus) and SPX-resistant S. aureus strains, with enhanced wound healing and minimal systemic toxicity. This approach, coupled with its minimalist design, presents a promising treatment option for the clinical management of biofilm-associated severe skin and soft tissue infections.

RevDate: 2025-05-30
CmpDate: 2025-05-30

Rattanakijkamol P, Promta P, Wanachantararak P, et al (2025)

Effectiveness of Novel Calcium Hydroxide Nanoparticles in the Different Vehicles against Mixed-species Biofilm: An In Vitro and Ex Vivo Study.

The journal of contemporary dental practice, 26(3):265-272.

AIM: To evaluate the antimicrobial effectiveness of calcium hydroxide nanoparticles [(Ca(OH)]2 NPs) with different vehicles against biofilm, composed of Enterococcus faecalis, Streptococcus gordonii, and Candida albicans, in vitro and ex vivo tooth models.

MATERIALS AND METHODS: The Alamar Blue assay was used to determine the minimum biofilm inhibitory concentration (MBIC), while the minimum biofilm eradication concentration (MBEC) was assessed by colony counting. Multispecies biofilms were inoculated in 50 root blocks with different medicaments (each n = 10). The colony-forming unit then assessed the viable cell counts. Morphological structures were analyzed with scanning electron microscopy (SEM).

RESULTS: The MBIC of all groups was 1:128 of primary concentration. The MBEC of Ca(OH)2 NPs in all formulas was two times higher than Ca(OH)2. Scanning electron microscopy analysis revealed biofilm disruption and debris clumping in both formulas, with the lowest viable cell count in Ca(OH)2NPs.

CONCLUSION: Calcium hydroxide nanoparticles in both formulas, especially the viscous formula, had the potential for antibiofilm activity.

CLINICAL SIGNIFICANCE: Calcium hydroxide nanoparticles, particularly in a viscous formula, are effective in significantly reducing mixed-species biofilms, suggesting their potential as an improved alternative to conventional Ca(OH)2 for endodontic treatment. How to cite this article: Rattanakijkamol P, Promta P, Wanachantararak P, et al. Effectiveness of Novel Calcium Hydroxide Nanoparticles in the Different Vehicles against Mixed-species Biofilm: An In Vitro and Ex Vivo Study. J Contemp Dent Pract 2025;26(3):265-272.

RevDate: 2025-05-30

Al-Haliem SM, Mohammed MJ, Hesarinejad MA, et al (2025)

Antimicrobial, Anti-Biofilm Activity and Antioxidants of Phenolic Compounds Isolated From Hypericum perforatum on Periodontal Pathogenic Oral Bacteria.

Food science & nutrition, 13(6):e70336.

Wild plants are a rich source of phenolic compounds with antimicrobial and antioxidant properties. This study extracted and analyzed Hypericum perforatum leaf fractions for their phenolic profile, antioxidant capacity, and activity against antibiotic-resistant oral bacteria. Phenolic compounds were identified using column chromatography, TLC, and HPLC. Four different fractions, two from ethyl acetate extraction and two from ethanolic extraction, were obtained and evaluated further. The antimicrobial activity of each fraction was assessed against two Gram-negative bacteria that cause gum disease, Morococcus cerebrosus and Eikenella corrodens, using the disc-diffusion assay. Fraction I exhibited the most potent antimicrobial activity against E. corrodens and M. cerebrosus, with 20-25 mm inhibition zones at lower concentrations. Fraction II showed limited activity, primarily at 100 and 200 μg/mL, while Fractions III and IV had moderate effects, with some concentrations effective against E. corrodens. Regarding biofilm formation, Fraction I showed the most significant reduction Fraction I showed the most significant reduction in biofilm formation for both E. corrodens and M. cerebrosus at 50 and 200 μg/mL concentrations. Fraction II demonstrated variable effects, with an increase in biofilm formation at 200 μg/mL for E. corrodens. At the same time, Fractions III and IV had moderate reductions in biofilm formation across most concentrations. The antioxidant activity of H. perforatum fractions, assessed via DPPH, surpassed Vitamin C at lower concentrations, with Fraction II showing the highest activity (83.98% at 500 ppm). These findings highlight H. perforatum as a promising natural source of phenolics with potential applications in managing periodontal infections.

RevDate: 2025-05-30

Almogbel M, Huq M, Almogbel M, et al (2025)

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.

RevDate: 2025-05-29
CmpDate: 2025-05-29

Marinacci B, D'Ambrosio C, Vitale I, et al (2025)

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.

RevDate: 2025-05-29

Wu J, Li J, Wang J, et al (2025)

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.

RevDate: 2025-05-29

Zhang SY, Sun SS, Liu LY, et al (2025)

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.

RevDate: 2025-05-29

Canellas ALB, Dias GR, Lopes IR, et al (2025)

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.

RevDate: 2025-05-29

Karaca B, Kyalo Kilonzo N, Korkmaz Ş, et al (2025)

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.

RevDate: 2025-05-28
CmpDate: 2025-05-28

Khudhair DN, Zwain HM, Siadatmousavi SM, et al (2025)

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.

RevDate: 2025-05-28
CmpDate: 2025-05-28

Wang A, Teng Y, Jin T, et al (2025)

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.

RevDate: 2025-05-28

Wang Q, Chu G, Gao C, et al (2025)

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.

RevDate: 2025-05-28

Yao W, Wang T, Sun W, et al (2025)

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.

RevDate: 2025-05-28

Ding K, Yang S, Hu H, et al (2025)

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.

RevDate: 2025-05-28
CmpDate: 2025-05-28

Astuty SD, Tabaika PM, Imelda I, et al (2025)

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.

RevDate: 2025-05-28

Song J, Chen G, Zhu W, et al (2025)

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.

RevDate: 2025-05-28

da Silva Filho RG, de Lima E Silva AA, de Meirelles Saramago CS, et al (2025)

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.

RevDate: 2025-05-28

Reynolds CA, Scuderi RA, Skidmore AL, et al (2025)

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.

RevDate: 2025-05-28

Zuniga K, Thompson M, Muire PJ, et al (2025)

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.

RevDate: 2025-05-28

Su J, Gu H, Huang X, et al (2025)

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.

RevDate: 2025-05-28
CmpDate: 2025-05-28

Guła G, Majkowska-Skrobek G, Misterkiewicz A, et al (2025)

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.

RevDate: 2025-05-28

Leite RF, Garcia BLN, Barbosa KDS, et al (2025)

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.

RevDate: 2025-05-28

Tang Z, Yousif M, Okyere SK, et al (2025)

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.

RevDate: 2025-05-28

Sousa H, Kinney KA, Sousa CA, et al (2025)

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.

RevDate: 2025-05-28

Belanche Monterde A, Flores-Fraile J, Pérez Pevida E, et al (2025)

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.

RevDate: 2025-05-28

Nawaz S, Shoaib M, Huang C, et al (2025)

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.

RevDate: 2025-05-28

Tedeschi S, Giannitsioti E, C Mayer (2025)

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.

RevDate: 2025-05-28

Marioni J, Romero BC, Mugas ML, et al (2025)

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.

RevDate: 2025-05-28
CmpDate: 2025-05-28

Galgano M, Pellegrini F, Mrenoshki D, et al (2025)

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.

RevDate: 2025-05-28
CmpDate: 2025-05-28

Kang YR, Park JY, Chung DR, et al (2025)

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.

RevDate: 2025-05-28

Xu X, Wang P, Tong F, et al (2025)

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.

RevDate: 2025-05-28
CmpDate: 2025-05-28

Barros MJ, Acuña LG, Hernández-Vera F, et al (2025)

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.

RevDate: 2025-05-28
CmpDate: 2025-05-28

Chotigawin R, Kandasamy B, Asa P, et al (2025)

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.

RevDate: 2025-05-28

Scaffo J, Lima RD, Dobrotka C, et al (2025)

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.

RevDate: 2025-05-28

Touati A, Mairi A, Ibrahim NA, et al (2025)

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.

RevDate: 2025-05-28

Alvira-Arill GR, Herrera OR, Stultz JS, et al (2025)

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.

RevDate: 2025-05-28

Paiva J, Silva V, Poeta P, et al (2025)

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.

RevDate: 2025-05-27

Song J, Yuan S, Liu S, et al (2025)

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.

RevDate: 2025-05-27
CmpDate: 2025-05-27

Javed MU, Ijaz M, Ahmed A, et al (2025)

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.

RevDate: 2025-05-27
CmpDate: 2025-05-27

Pérez-Gómez O, Domínguez-Maqueda M, García-Márquez J, et al (2025)

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.

RevDate: 2025-05-27

Hussain Y, Dormocara A, Li H, et al (2025)

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.

RevDate: 2025-05-27

Altenburger MJ, Bergmann ME, Ledernez LA, et al (2025)

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.

RevDate: 2025-05-27

Vodianyk A, Poniatovskiy V, V Shyrobokov (2025)

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.

RevDate: 2025-05-27

Bachtiar BM, Rieuwpassa IE, Susilowati H, et al (2025)

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.

RevDate: 2025-05-27

Nocera FP, Chiaromonte A, Schena R, et al (2025)

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.

RevDate: 2025-05-26

Chen L, Wang L, Mao Y, et al (2025)

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.

RevDate: 2025-05-27
CmpDate: 2025-05-25

Hanafy MS, Kamal NM, HA Fathallah (2025)

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.

RevDate: 2025-05-25

Erdem Aynur Z, Başbülbül G, Karaynir A, et al (2025)

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.

RevDate: 2025-05-25
CmpDate: 2025-05-25

Farshadzadeh Z, Khoshnood S, Akrami S, et al (2025)

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.

RevDate: 2025-05-24
CmpDate: 2025-05-24

Warrier A, Satyamoorthy K, TS Murali (2025)

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.

RevDate: 2025-05-24
CmpDate: 2025-05-24

Wang C, Tian Z, Luan X, et al (2025)

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.

RevDate: 2025-05-24

Canales-Huerta N, Cádiz M, Ulloa MT, et al (2025)

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.

RevDate: 2025-05-23

Saleem M, Khan MS, Neyaz A, et al (2025)

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.

RevDate: 2025-05-26
CmpDate: 2025-05-23

Najm MAA, Shakir HA, Hasen ST, et al (2025)

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.

RevDate: 2025-05-25

Wang X, Hu J, Chen C, et al (2025)

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.

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.

cover-pic

SUPPORT ESP: Order from Amazon
The ESP project will earn a commission.

This is a must read book for anyone with an interest in invasion biology. The full title of the book lays out the author's premise — The New Wild: Why Invasive Species Will Be Nature's Salvation. Not only is species movement not bad for ecosystems, it is the way that ecosystems respond to perturbation — it is the way ecosystems heal. Even if you are one of those who is absolutely convinced that invasive species are actually "a blight, pollution, an epidemic, or a cancer on nature", you should read this book to clarify your own thinking. True scientific understanding never comes from just interacting with those with whom you already agree. R. Robbins

Electronic Scholarly Publishing
961 Red Tail Lane
Bellingham, WA 98226

E-mail: RJR8222 @ gmail.com

Papers in Classical Genetics

The ESP began as an effort to share a handful of key papers from the early days of classical genetics. Now the collection has grown to include hundreds of papers, in full-text format.

Digital Books

Along with papers on classical genetics, ESP offers a collection of full-text digital books, including many works by Darwin and even a collection of poetry — Chicago Poems by Carl Sandburg.

Timelines

ESP now offers a large collection of user-selected side-by-side timelines (e.g., all science vs. all other categories, or arts and culture vs. world history), designed to provide a comparative context for appreciating world events.

Biographies

Biographical information about many key scientists (e.g., Walter Sutton).

Selected Bibliographies

Bibliographies on several topics of potential interest to the ESP community are automatically maintained and generated on the ESP site.

ESP Picks from Around the Web (updated 28 JUL 2024 )