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 27 Mar 2025 at 01:40 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: 2025-03-24

Sathiaseelan A, Song KP, Tan HS, et al (2025)

Antibiofilm activity of Clitoria ternatea flowers anthocyanin fraction against biofilm-forming oral bacteria.

FEMS microbiology letters pii:8092647 [Epub ahead of print].

This study investigated the antibiofilm effects of Clitoria ternatea flowers anthocyanin fraction (AF) on Streptococcus mutans, Actinomyces viscosus and Aggregatibacter actinomycetemcomitans. AF was obtained using column chromatography, and liquid chromatography-mass spectrometry was employed for its characterization and identification. The crystal violet assay and scanning electron microscopy analysis revealed significant inhibition of early biofilm formation and destruction of preformed biofilms after AF treatment (0.94-15 mg mL-1). Anti-adhesion assay on acrylic teeth demonstrated that AF effectively hampered sucrose dependent and independent attachment. Importantly, growth curve and pH drop assays showed that AF inhibited pH reduction for all bacteria tested without hindering bacterial growth. Furthermore, the tetrazolium-based cytotoxicity assay indicated no toxicity towards normal human gingival fibroblasts (HGF-1) at 0.78-12.5 mg mL-1. These findings suggest C. ternatea anthocyanins are promising antibiofilm agents for oral biofilm control, acting during both initial formation and on mature biofilms.

RevDate: 2025-03-24

Song Y, Zhu J, Lv Y, et al (2025)

Temperature-Triggered Reversible Adhesion Hydrogel with Responsive Drug Release, Mild Photothermal Therapy, and Biofilm Clearance for Skin Infection Healing.

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

Bacterial infection gives rise to a hypoxic, H2O2-abundant, and acidic local microenvironment at the site of inflammation, which prevents the healing of skin tissues. In this work, gelatin and oxidized carboxymethyl cellulose were developed as the framework of hydrogels. Tannic acid and 3-formylphenylboronic acid served as small-molecule anchors. Through the introduction of multiple dynamic cross-linkings, the hydrogel was endowed with various functions. These functions encompassed mechanical compatibility with the skin, reversible adhesion characteristics, and rapid self-healing capabilities. In addition, nanoflower-like MnO2 microparticles loaded with berberine hydrochloride were embedded. MnO2 has the ability not only to kill bacteria through the photothermal effect (PTT) but also to catalyze the decomposition of H2O2 and release oxygen, effectively improving the inflammatory microenvironment. Remarkably, based on the drug/PTT synergistic strategy, the hydrogel exhibited significant antibacterial activity and biofilm removal ability under mild conditions (<50 °C), avoiding thermal damage to healthy tissues. Consequently, the hydrogels demonstrate favorable biocompatibility, significant cell proliferation, migration, angiogenesis, collagen deposition, and tissue regeneration. Therefore, the multifunctional antimicrobial hydrogel is expected to be a skin-friendly medical dressing with enormous potential in the treatment of skin and soft tissue infections.

RevDate: 2025-03-24

Duymaz FZ, Budak F, E Okumuş (2025)

Genotypic analysis and biofilm formation of Acinetobacter baumannii clinical isolates.

Acta microbiologica et immunologica Hungarica [Epub ahead of print].

Acinetobacter baumannii is a significant nosocomial pathogen recognized for its multidrug-resistance (MDR) and capacity to endure in hospital settings. This study aims to investigate the clonal relationships of A. baumannii isolates from diverse clinical samples, identify the sequence types of MDR isolates, and examine biofilm formation activity and biofilm-associated genes that contribute to persistence in hospital settings. A total of 90 A. baumannii isolates were analyzed. Bacterial identification and antibiotic susceptibility testing were conducted with MALDI-TOF MS and Vitek-2. REP-PCR was utilized to evaluate clonal connections, MLST was employed for specific isolates. Biofilm formation activity was assessed using the XTT reduction assay, and biofilm-associated genes were identified by PCR. REP-PCR revealed 29 genotypes, with Genotype A being identified as the endemic clone in 59% of isolates. Two isolates representing this genotype were found to belong to the ST2 clone. The majority of A. baumannii isolates possess biofilm-related genes and exhibit strong biofilm activity. In MDR isolates, ompA and csuE positivity were significantly higher than those non-MDR isolates (P = 0.003, P = 0.001). The csuE positive isolates were found to have significantly stronger biofilm activity than negative ones (P = 0.009). This study emphasizes the prevalence of a hospital-endemic, MDR A. baumannii genotype A, ST2 clone, and the genetic variability across isolates. No direct correlation was noted between MDR status and biofilm formation; however, some biofilm-related genes, notably csuE, were linked to stronger biofilm activity. These findings underscore the necessity for ongoing molecular surveillance and infection control measures to avert the dissemination of MDR A. baumannii in healthcare environments.

RevDate: 2025-03-25
CmpDate: 2025-03-24

Cai R, Cheng Q, Zhao J, et al (2025)

Sericin-Assisted Green Synthesis of Gold Nanoparticles as Broad-Spectrum Antimicrobial and Biofilm-Disrupting Agents for Therapy of Bacterial Infection.

International journal of nanomedicine, 20:3559-3574.

BACKGROUND: Tens of millions of people die from wound infections globally each year, and nearly 80% of tissue infections are associated with bacterial biofilms. However, overuse of antibiotics can lead to bacterial resistance. Therefore, it is critical to develop simple and effective strategies to kill bacteria and remove biofilms.

METHODS: The present study used sericin as a reducing and stabilizing agent to synthesize sericin-gold nanoparticles (Ser-Au NPs) and tested its colloidal stability under different pH and salt concentration conditions. Subsequently, functional gold nanocomposites (Ser-Au@MMI) were synthesized by combining Ser-Au NPs with 2-mercapto-1-methylimidazole (MMI). The antimicrobial effect of Ser-Au@MMI was checked by MIC, antimicrobial activity test, and in vitro cytotoxicity was assessed using CCK-8 assay. In vitro anti-biofilm effect was observed by fluorescence microscopy and SEM. Finally, the anti-infective therapeutic efficacy of Ser-Au@MMI was determined in an in vivo rat-infected wound model.

RESULTS: Sericin as a reducing and stabilizing agent to synthesize Ser-Au NPs exhibited excellent colloidal stability under different pH and salt concentration conditions. The TEM, EDS, and XPS analyses confirmed the successful synthesis of Ser-Au@MMI. It exhibited higher antibacterial activity due to the synergistic effect of MMI and AuNP, which can achieve a bactericidal effect by destroying the integrity of bacterial cell walls and structure. In addition, Ser-Au@MMI10 (HAuCl4:MMI =1:10) concentration (64 μg/mL) could effectively disrupt biofilms formed by four species of bacteria and kill them, including P. aeruginosa, B. subtilis, E. coli, and S. aureus, but was not cytotoxic to mouse fibroblasts (L929) cells. Infected wound modeling showed that Ser-Au@MMI10 accelerated infected wound healing in vivo.

CONCLUSION: Ser-Au@MMI nanocomposites are prepared through a facile and environmentally friendly strategy and have the advantages of excellent bactericidal effect and low toxicity, which has the potential for application as a broad-spectrum antimicrobial agent and biofilm disrupting agent in healthcare.

RevDate: 2025-03-25

Gerschler S, Maaß S, Gerth P, et al (2025)

Drosera rotundifolia L. as E. coli biofilm inhibitor: Insights into the mechanism of action using proteomics/metabolomics and toxicity studies.

Biofilm, 9:100268.

The successful sustainable cultivation of the well-known medicinal plant sundew on rewetted peatlands not only leads to the preservation of natural populations, but also provides a basis for the sustainable pharmaceutical use of the plant. The bioactive compounds of sundew, flavonoids and naphthoquinones, show biofilm-inhibiting properties against multidrug-resistant, ESBL-producing E. coli strains and open up new therapeutic possibilities. This study investigates the molecular mechanisms of these compounds in biofilm inhibition through proteomic analyses. Specific fractions of flavonoids and naphthoquinones, as well as individual substances like 7-methyljuglone and 2″-O-galloylhyperoside, are analyzed. Results show that naphthoquinones appear to act via central regulatory proteins such as OmpR and alter the stress response while flavonoids likely affect biofilm formation by creating an iron-poor environment through iron complexation and additionally influence polyamine balance, reducing intracellular spermidine levels. Further investigations including assays for iron complexation and analysis of polyamines confirmed the proteomic data. Safety evaluations through cytotoxicity tests in 3D cell cultures and the Galleria mellonella in vivo model confirm the safety of the extracts used. These findings highlight sundew as a promising candidate for new phytopharmaceuticals.

RevDate: 2025-03-25

Kakahi FB, Martinez JA, Avitia FM, et al (2025)

Release of extracellular DNA by Pseudomonas sp. as a major determinant for biofilm switching and an early indicator for cell population control.

iScience, 28(3):112063.

In Pseudomonas sp., the switch from planktonic to sessile state is driven by extracellular DNA release. We observed a subpopulation of cells associated with eDNA in the planktonic phase, as indicated by propidium iodide staining. Surprisingly, the size of this subpopulation was directly correlated with the overall biofilm-forming capacity of the population. This challenges the prevailing understanding of phenotypic switching and confirms that biofilm formation in Pseudomonas is a collective process governed by eDNA release. Automated flow cytometry tracked the process, and PI-positive cells were identified as an early indicator of biofilm formation. Automated glucose pulsing successfully reduced biofilm formation by interfering with PI-positive cell proliferation. This study provides insights into the collective determinants of biofilm switching in Pseudomonas putida and introduces a potential strategy for controlling biofilm formation.

RevDate: 2025-03-25

Javadi K, Ahmadi MH, Rajabnia M, et al (2025)

Effects of Curcumin on Biofilm Production and Associated Gene in Multidrug-Resistant Acinetobacter baumannii Isolated from Hospitalized Patients.

International journal of molecular and cellular medicine, 14(1):567-575.

Multi-drug-resistant (MDR) Acinetobacter baumannii has become a major global healthcare concern due to its opportunistic infections and high antibiotic resistance. This investigation is intended to investigate curcumin's potential anti-bacterial and antibiofilm impacts on MDR A. baumannii and to present a promising strategy for fighting against infections caused by this pathogen. This cross-sectional investigation comprised 34 MDR A. baumannii clinical isolates. The Kirby-Bauer disc diffusion method evaluated the sensitivity of isolates to multifaceted anti-bacterial agents. The microdilution broth method quantified curcumin's minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC). The efficacy of curcumin in inhibiting MDR A. baumannii biofilm was assessed via 96-well microtiter plates. The expression of the biofilm-associated protein (bap) gene was evaluated by employing quantitative real-time PCR (qRT-PCR). Within the 34 MDR A. baumannii isolates, the highest resistance was noted for trimethoprim/sulfamethoxazole and ciprofloxacin, with all 34 isolates (100%) indicating resistance. The lowest resistance was noted for ampicillin/sulbactam, with 22 isolates (64.7%) exhibiting resistance. The MICs of curcumin ranged from 0.625 to 2.5 mg/ml, while the MBCs varied between 1.25 to 5 mg/ml. Curcumin reduced biofilm formation by 25% to 91%, depending on the concentration. In contrast to the untreated control, the average relative activity of the bap gene in MDR A. baumannii isolates declined by 62.07%. The findings indicate that curcumin demonstrates antimicrobial and anti-biofilm activities against MDR A. baumannii. The downregulation noted in the bap gene further supports the curcumin's anti-biofilm impact.

RevDate: 2025-03-24

Grzech-Leśniak Z, Pyrkosz J, Szwach J, et al (2025)

In vitro evaluation of the effect of Er:YAG laser with a fractional PS04 handpiece on microbial biofilm survival.

Dental and medical problems [Epub ahead of print].

BACKGROUND: The oral microbiota consists of a diverse range of microorganisms, with Streptococcus spp. and Candida spp. frequently coexisting in oral infections.

OBJECTIVES: The aim of the study was to investigate the impact of Er:YAG (erbium-doped yttrium aluminum garnet) laser therapy, utilizing the PS04 fractional beam, on the in vitro growth and biofilm formation of clinical strains of Candida albicans, Candida glabrata and Streptococcus mutans.

MATERIAL AND METHODS: Singleand dual-species planktonic cultures and biofilms were exposed to an Er:YAG laser using a fractional PS04 handpiece. The effects of the laser were evaluated immediately after irradiation and 24 h post-irradiation by measuring colony-forming units per milliliter (CFU/mL). Biofilm biomass (singleand dual-species) was quantified using the crystal violet staining method. The study tested 2 sets of laser parameters: group 1 (T1): 1.5 W, 10 Hz, 30 s, 0.4 J/cm2, irradiance: 3.9 W/cm2; and group 2 (T2): 6.15 W, 10 Hz, 30 s, 1.6 J/cm2, irradiance: 16 W/cm2. Non-irradiated samples served as controls. The parameters were selected based on their frequent clinical use for snoring treatment and facial rejuvenation.

RESULTS: Candida albicans exhibited a significantly greater reduction under T2 settings in comparison to T1 (85.3 ±1.2% vs. 43.9 ±4.5%, respectively; p = 0.006) within single-species biofilms. For C. glabrata, a significant reduction was observed under T1 parameters (69.8 ±14.9%). Furthermore, S. mutans demonstrated a significantly higher reduction at T2 settings (97.1 ±0.6%) compared to T1 settings (81.1 ±19.6%), with statistically significant differences noted between S. mutans and both C. albicans and C. glabrata under T1, as well as between S. mutans and C. glabrata under T2. In dual-species biofilms, T2 fluence led to greater reductions in C. glabrata, S. mutans and C. albicans in mixed cultures (p < 0.05).

CONCLUSIONS: The Er:YAG laser, when used in conjunction with the PS04 handpiece, demonstrated a substantial reduction in the biofilms of C. albicans and C. glabrata. Higher fluence maintained reductions over a 24-h period, particularly in the case of C. glabrata and S. mutans. This study highlights the antifungal potential of low-fluence laser settings that are commonly used in facial aesthetic procedures and snoring treatment.

RevDate: 2025-03-23

Kanthenga HT, Banicod RJS, Ntege W, et al (2025)

Functional diversity of AI-2/LuxS system in Lactic Acid Bacteria: Impacts on Biofilm Formation and Environmental Resilience.

Research in microbiology pii:S0923-2508(25)00031-2 [Epub ahead of print].

A key component of microbial communication, autoinducer-2 (AI-2) signaling, affects several physiological processes, including environmental adaptation and biofilm formation in lactic acid bacteria (LAB). The multifarious contribution of AI-2, synthesized by LuxS, in improving biofilms and tolerance to hostile conditions in LAB has been investigated in this review. The evolutionary conservation and diversity of AI-2 are shown by a phylogenetic analysis of luxS gene among several LAB species. Furthermore, AI-2 signaling in LAB improves resistance to unfavorable environmental factors, including pH fluctuations, temperature extremes, and antimicrobial agents. Lactic acid bacteria could set off defenses against harmful impacts from environmental stresses.

RevDate: 2025-03-23
CmpDate: 2025-03-23

Ma H, Liu D, Song C, et al (2025)

Cefoxitin inhibits the formation of biofilm involved in antimicrobial resistance MDR Escherichia coli.

Animal biotechnology, 36(1):2480176.

The study investigates the relationship between biofilm formation and antibiotic resistance in Escherichia coli (E. coli) isolated from calves. Using biochemical and molecular methods, we identified the isolates and assessed their biofilm-forming ability through an improved crystal violet staining method. The minimum inhibitory concentrations (MICs) of 18 antibiotics against the isolates were determined using the broth microdilution method. The impact of cefoxitin on biofilm formation was analyzed using laser scanning confocal microscopy (LSCM). Additionally, qRT-PCR was employed to evaluate the expression levels of biofilm-related genes (luxS, motA, fliA, pfs, and csgD) in response to varying cefoxitin concentrations. Results indicated a significant correlation between antimicrobial resistance (AMR) and biofilm formation ability. Cefoxitin effectively reduced biofilm formation of multidrug-resistant E. coli isolates at 1/2 and 1 MIC, with enhanced inhibition at higher concentrations. The QS-related genes luxS, pfs, motA, and fliA were downregulated, leading to decreased csgD expression. At 1/2 MIC, csgD expression was significantly reduced. In conclusion, cefoxitin inhibits biofilm formation in multidrug-resistant E. coli by down-regulating key genes, offering a potential strategy to mitigate resistance and control infections in calves caused by biofilm-positive E. coli isolates.

RevDate: 2025-03-23

Wu L, Li P, Wang G, et al (2025)

High-efficiency nitrogen and phosphorus removal for low C/N rural wastewater using a full-scale multi-stage A[2]O biofilm reactor combined with horizontal-vertical flow constructed wetlands system.

Journal of environmental management, 380:125023 pii:S0301-4797(25)00999-5 [Epub ahead of print].

Rural wastewater treatment faces significant challenges in achieving stable effluent quality due to factors such as temperature fluctuations, variations in water quality and quantity, and low carbon-to-nitrogen (C/N) ratios. This study developed a full-scale, non-membrane, multi-stage anaerobic-anoxic-oxic (MSA[2]O) biofilm reactor integrated with horizontal-vertical flow constructed wetlands (HVCWs), which was operated continuously for approximately 320 days with an average flow of 11.9 m[3]/d in a rural area of northern China. Key parameters were optimized: hydraulic retention time (HRT) of 21-32 h, aeration rate of 4.0 m[3]/h, carbon source dosing at 1.25 L/h, PAC dosing at 0.55 L/h, and mixed liquor reflux ratio at 200 %. The system demonstrated high removal efficiencies for COD (74.2 %), NH4[+]-N (93.4 %), TN (90.6 %), and TP (86.3 %), consistently meeting the class 1A of GB18918-2002, China (COD ≤50 mg/L, NH4[+]-N ≤ 5 mg/L, TN ≤ 15 mg/L, TP ≤ 0.5 mg/L), even under challenging conditions such as low C/N (3.3) and rainy seasons. More than 70 % of nitrogen and phosphorus were removed in the MSA[2]O system. Microbial analysis revealed the enrichment of many functional bacteria. Proteobacteria play a key role in denitrification and phosphorus removal. Actinomycetes, Acidobacteria, and Firmicutes to nitrogen fixation and organic matter degradation. Nitrosomonas dominated ammonia oxidation, while Dechloromonas and Accumulibacter significantly contributed to phosphorus uptake. Seasonal variations in microbial diversity enabled consistent and highly efficient nutrient removal. The HVCWs system contributed 16.3 % of total phosphorus removal through selected plant species and phosphorus-absorbing modified ceramsite, ensuring effluent polishing and stability. With low operational costs ($0.12/m[3]), the integrated system provides an effective and scalable solution for rural wastewater treatment, delivering high-quality effluent with minimal energy consumption.

RevDate: 2025-03-23

Kim YG, Jeon H, Boya BR, et al (2025)

Targeting biofilm formation in Candida albicans with halogenated pyrrolopyrimidine derivatives.

European journal of medicinal chemistry, 290:117528 pii:S0223-5234(25)00293-4 [Epub ahead of print].

Growing concern over environmental contaminants, including pharmaceuticals and antifungal agents, highlights their role in promoting resistance and biofilm formation by microorganisms. Antifungal resistance, especially in drug-resistant Candida spp., poses a global threat, worsened by the widespread use of antifungal agents in both clinical applications and environmental contamination. This study investigates the antibiofilm properties of various halogenated pyrrolo pyrimidine derivatives, specifically 4-chloro-5-iodo-7H-pyrrolo[2,3-d]pyrimidine (10) and 2,4-dichloro-5-iodo-7H-pyrrolo[2,3-d]pyrimidine (16), against fluconazole-resistant C. albicans. Both compounds demonstrated strong biofilm inhibition, with 16 showing greater efficacy even at lower concentrations. qRT-PCR analysis revealed downregulation of key biofilm- and hyphae/germ tube-relating genes, including ALS3, HWP1, and ECE1, alongside upregulation of stress response and biofilm regulator genes such as CDR11, GST3, IFD6, UCF1, YWP1, and ZAP1, indicating complex regulatory responses to the treatments. Molecular docking analysis revealed that these compounds bind effectively to the binding cavity of the ALS3 protein, with halogen atoms playing a key role in stabilizing interaction. Compound 16 exhibited minimal cytotoxicity in Brassica rapa and Caenorhabditis elegans models, suggesting a favorable ADMET safety profile. Confocal microscopy analysis confirmed the compounds effectiveness in preventing biofilm formation when applied as biodegradable PLGA coatings on biomaterial surfaces. These findings suggest that 16 holds promise as a potent antifungal agent with reduced environmental impact, offering both efficacy and sustainability.

RevDate: 2025-03-24

Qin S, Chen W, Lin Y, et al (2025)

Effect of hydraulic retention time on the nitrogen removal performance of pure biofilm rotating biological contactor system inoculated with heterotrophic nitrification-aerobic denitrification bacteria and its corresponding mechanism.

Bioresource technology, 427:132428 pii:S0960-8524(25)00394-3 [Epub ahead of print].

The traditional activated sludge biofilm system struggles with poor removal performance and long hydraulic retention time (HRT) in treating high ammonia nitrogen (NH4[+]-N) wastewater. To solve these problems, this study introduced a pure heterotrophic nitrification-aerobic denitrification (HN-AD) biofilm system which HN-AD bacteria were inoculated in the rotating biological contactor (PH-RBC), with free microorganisms discharged after biofilm formation. Under short HRT (12 h), PH-RBC exhibited 29.23 % and 31.03 % higher NH4[+]-N and total nitrogen (TN) removal than pure activated sludge biofilm RBC (PS-RBC) (the influent NH4[+]-N was 505 ± 45 mg/L). Flavobacterium and Azoarcus were crucial for nitrogen removal in the PH-RBC. Metabolic analysis revealed that genes CS and IDH3 are crucial for carbon metabolism, with dissimilatory nitrate reduction dominates nitrogen metabolism. Bugbase prediction indicated that decreasing HRT increased the presence of Potentially Pathogenic. This study provides a theoretical basis for using pure biofilm system in high NH4[+]-N wastewater treatment.

RevDate: 2025-03-22
CmpDate: 2025-03-22

Zhang M, Zhu Y, Li X, et al (2025)

GepA, a GGDEF-EAL protein, regulates biofilm formation and swimming motility in Vibrio parahaemolyticus.

Archives of microbiology, 207(5):99.

Cyclic diguanylate monophosphate (c-di-GMP) is a second messenger that regulates multiple bacterial behaviors. It is synthesized by diguanylate cyclase (DGC) with the GGDEF domain, and degraded by phosphodiesterase (PDE) with the EAL or HD-GYP domain. The GepA (VP0117) protein in Vibrio parahaemolyticus contains both GGDEF and EAL domains, but its role remains unknown. This study found that deletion of the EAL domain or both the GGDEF and EAL domains in GepA increased intracellular c-di-GMP levels, enhanced biofilm formation, and inhibited polar flagellum-mediated swimming motility. Deletion of only the GGDEF domain had no such effects. Additionally, removing the EAL domain or both the GGDEF and EAL domains increased cpsA expression and decreased polar flagellar gene expression, while deleting the GGDEF domain alone had no impact on these genes. Overexpression of GepA or a GepA variant with a mutated GGDEF domain reduced biofilm formation but increased swimming motility. However, overexpression of GepA with a mutated EAL domain did not produce the expected phenotypic changes. In summary, GepA functions as a PDE to degrade c-di-GMP, thereby suppressing biofilm formation and enhancing swimming motility in V. parahaemolyticus.

RevDate: 2025-03-22

Scott E, Bullerjahn GS, CG Burkhart (2025)

Targeting the Cutibacterium acnes Biofilm in Acne.

International journal of dermatology [Epub ahead of print].

RevDate: 2025-03-24
CmpDate: 2025-03-22

Francisco M, R Grau (2025)

Biofilm proficient Bacillus subtilis prevents neurodegeneration in Caenorhabditis elegans Parkinson's disease models via PMK-1/p38 MAPK and SKN-1/Nrf2 signaling.

Scientific reports, 15(1):9864.

Parkinson's disease (PD) is a no-curable neurodegenerative disease of pandemic distribution for which only palliative treatments are available. A hallmark of PD is injury to dopaminergic neurons in the substantia nigra pars compacta. Here, we report that Caenorhabditis elegans colonized by biofilm-forming Bacillus subtilis is resistant to injury of dopaminergic neurons caused by treatment with the PD-related neurotoxin 6-hydroxydopamine (6-OHDA). Biofilm-forming B. subtilis-colonized C. elegans display dopamine-dependent behaviors indistinguishable from those of 6-OHDA-untreated worms colonized by gut commensal E. coli OP50. In C. elegans PD model strains with early dopaminergic neuron decay or overexpressing human alpha-synuclein, biofilm-forming B. subtilis colonization had neuroprotective effects and prevents alpha-synulcein aggregation, respectively. The B. subtilis-controlled insulin/IGF-1 signaling (ILS), whose downregulation prevents aging-related PD, is not involved in protecting against 6-OHDA-related injury. We demonstrate that biofilm-forming B. subtilis activates PMK-1 (p38 MAPK)/SKN-1 (Nrf2) signaling, which protects C. elegans from 6-OHDA-induced dopaminergic neuron injury.

RevDate: 2025-03-22

Sun Z, Li B, J Liu (2025)

Synchronous vanadium bio-reduction/detoxification/recovery and nitrogen attenuation in a membrane aerated biofilm reactor.

Environmental pollution (Barking, Essex : 1987), 372:126095 pii:S0269-7491(25)00468-3 [Epub ahead of print].

The presence of both pentavalent vanadium [V(Ⅴ)] and nitrogen in wastewaters from vanadium smelting poses significant environmental challenges. However, it remains little in the way of continuous flow biological reactor to concurrently eliminated V(Ⅴ) and nitrogen in wastewaters. Herein, membrane-aerated biofilm reactor (MABR) system was designed to achieve simultaneous nitrification and denitrification (SND) alongside biological reduction, detoxification, and recovery of vanadium. Vanadium and nitrogen removal performances, solid-state characterization, microbial compositions and functional genes, and the mechanism related to the metabolism of vanadium and nitrogen were illuminated. Notably, we identified a potential role for biofilm-derived "secretion" in the transformation of V(Ⅴ) and nitrogen. Our findings revealed that the system achieved SND efficiency of 98.00 ± 0.57 % and removed 91.10 ± 3.60 % of total vanadium (TV) even at high influent V(Ⅴ) concentrations in continuous flow stage. Batch experiments implied that the conversion of NH4[+]-N was the limiting process of nitrogen removal in MABR system, and the extracellular polymeric substances (EPS) might play an important role in the conversion of V(Ⅴ) and nitrogen. V(Ⅴ) was reduced to V(Ⅳ), which was immobilized to biofilm and "secretion" by microbial surface functional groups, including C-O, O-C=O and -OH. Acinetobacter, Dechlorobacter, Denitratisoma and Nitrospira were verified as microbes associated with V(Ⅴ) and nitrogen metabolism. The abundance of functional genes pertaining to electron donor, electron transport, and electron acceptor systems increased under high V(V) stimulation. Collectively, the cooperation of biofilm and "secretion" ensured the intensive removal of vanadium and nitrogen. This study provides new insights into the concurrent removal of heavy metal and environmental nutrient.

RevDate: 2025-03-21

Habib MB, Batool G, Shah NA, et al (2025)

Biofilm-Mediated Infections; Novel Therapeutic Approaches and Harnessing Artificial Intelligence for Early Detection and Treatment of Biofilm-Associated Infections.

Microbial pathogenesis pii:S0882-4010(25)00222-0 [Epub ahead of print].

A biofilm is a group of bacteria that have self-produced a matrix and are grouped together in a dense population. By resisting the host's immune system's phagocytosis process and attacking with anti-microbial chemicals such as reactive oxygen and nitrogen species, a biofilm enables pathogenic bacteria to evade elimination. One of the major problems in managing chronic injuries is treating wounds colonized by biofilms. These days, a major issue is the biofilms, which exacerbate infection pathogenesis and severity. Numerous investigators have already discovered cutting-edge methods for biofilm manipulation. Using phytochemicals is a practical tactic to control and prevent the production of biofilms. Numerous studies conducted in the last few years have demonstrated the antibacterial and antibiofilm qualities of nanoparticles (NPs) against bacteria, fungi, and protozoa. Because hydrogel has antibiofilm properties, it has been employed extensively in wound care recently. It may be removed with ease and without causing trauma. Today, artificial intelligence (AI) is being used to improve these tactics by providing customized treatment alternatives and predictive analytics. Artificial intelligence (AI) algorithms have the capability to examine extensive datasets and detect trends in biofilm formation and resistance mechanisms. This can aid in the creation of more potent antimicrobial drugs. AI models analyze complex datasets, predict biofilm formation, and guide the design of personalized treatment strategies by identifying resistance mechanisms and therapeutic targets with exceptional precision. This review provides an integrative perspective on biofilm formation mechanisms and their role in infections, highlighting the innovative applications of AI in this domain. By integrating data from diverse biological systems, AI accelerates drug discovery, optimizes treatment regimens, and enables real-time monitoring of biofilm dynamics. From predictive analytics to personalized care, we explore how AI enhances biofilm diagnostics and introduces precision medicine in biofilm-associated infections. This approach not only addresses the limitations of traditional methods but also paves the way for revolutionary advancements in infection control, antimicrobial resistance management, and improved patient outcomes.

RevDate: 2025-03-21

Sahu S, Ghosal P, Patel H, et al (2025)

A comprehensive review on the treatment of pharmaceutically active compounds using moving bed biofilm reactor: A systematic meta-analysis coupled with meta-neural approach.

Journal of environmental management, 380:124865 pii:S0301-4797(25)00841-2 [Epub ahead of print].

Pharmaceutically active compounds (PhACs) in wastewater pose challenges to cleaner environment due to their recalcitrance and toxicity, restricting the use of conventional treatment methods. On the other hand, advanced oxidation processes face technical complexity and financial constraints, which also discourage their applicability especially in large scale treatment system. Moving Bed Biofilm Reactor (MBBR) as an advanced biological treatment system has shown remarkable efficacy and cost-effectiveness in treating various PhACs. However, studies report significant variations in the efficacy of MBBR across removing different pollutants, leading to a complication in their performance assessment. The present review has targeted a systematic meta-analysis coupled with a meta-neural approach over the conventional bibliometric study. The statistical approach resolves the publication bias and associated formation of a pertinent databases, providing significant insights into MBBR's performance and process variables. The novel approach of meta-neural exhibited a multivariate prediction model with a significant F value of 257.66 and a p-value of <0.001 relating the role of various process parameters on the treatment efficacy. Among various pharmaceuticals, beta-blockers were eliminated most effectively by MBBR technology, with removal rates exceeding those of antibiotics, analgesics, antidepressants, fibrates, and anticonvulsants. Sensitivity analysis revealed the significant influence of the operating parameters on the outcome in the order of initial COD > HRT > filling ratio > pH > initial concentration of the contaminant. The present meta-analysis approach vis-à-vis meta-neural is instrumental for delineating the technology selection and design for removing PhACs or other emerging contaminants.

RevDate: 2025-03-21

Ghiraldelli GHS, Iost RM, Sedenho GC, et al (2025)

Yeast biofilm synapse: an intra-kingdom pathway to high-density current output in bioelectronic devices.

Journal of materials chemistry. B [Epub ahead of print].

The quest to understand and harness microbial biofilms for energy generation has become increasingly important in the development of bioelectronic devices. Saccharomyces cerevisiae, a model organism, provides unique insights into how biofilms coordinate metabolic activities via extracellular polymeric substances (EPS). Beyond serving as a structural scaffold, EPS facilitates electrochemical signalling, enabling cellular communication and optimized electron transfer. This study demonstrates that encapsulating Saccharomyces cerevisiae in a hydrogel matrix enhances biofilm organization and significantly boosts bioelectricity generation, leveraging EPS as an electrochemical communication network. The concept of a "yeast synapse" is introduced, drawing parallels between microbial biofilms and synaptic signalling observed in higher organisms, with coordinated electron transfer and metabolic synchronization. It can drive advancements in bioelectrochemical system design and enhance the current output of sustainable bioelectronic devices.

RevDate: 2025-03-21

Bhattacharya M, Scherr TD, Lister J, et al (2025)

Extracellular adherence proteins reduce matrix porosity and enhance Staphylococcus aureus biofilm survival during prosthetic joint infection.

Infection and immunity [Epub ahead of print].

Biofilms are a cause of chronic, non-healing infections. Staphylococcus aureus is a proficient biofilm-forming pathogen commonly isolated from prosthetic joint infections that develop following primary arthroplasty. Extracellular adherence protein (Eap), previously characterized in planktonic or non-biofilm populations as being an adhesin and immune evasion factor, was recently identified in the exoproteome of S. aureus biofilms. This work demonstrates that Eap and its two functionally orphaned homologs EapH1 and EapH2 contribute to biofilm structure and prevent macrophage invasion and phagocytosis in these communities. Biofilms unable to express Eap proteins demonstrated increased porosity and reduced biomass. We describe the role of Eap proteins in vivo using a mouse model of S. aureus prosthetic joint infection. The Results suggest that the protection conferred to biofilms by Eap proteins is a function of biofilm structural stability that interferes with the leukocyte response to biofilm-associated bacteria.

RevDate: 2025-03-21

Tao H, Zhang W, Liu J, et al (2025)

The impact of the flagellar protein gene fliK on Helicobacter pylori biofilm formation.

mSphere [Epub ahead of print].

The biofilm structure of Helicobacter pylori is known to enhance its capabilities for antimicrobial resistance. This study aims to investigate the role of the flagellar hook length control protein gene fliK in the biofilm formation of H. pylori. Homologous recombination was employed to knock out the fliK gene in the H. pylori NCTC 11637 strain. The flagella of H. pylori were observed using transmission electron microscopy (TEM), whereas H. pylori motility and growth were examined through semi-solid agar assays and growth curve analyses, respectively. The bacterial biofilm and its constituents were visualized utilizing fluorescence confocal microscopy. Assessments of H. pylori adhesion to gastric mucosal cells, its vacuolar toxicity, and antibiotic resistance were evaluated using co-culture experiments and E-test methods. The fliK gene was successfully knocked out in H. pylori NCTC 11637. The ΔfliK mutant exhibited polyhook structures or lacked typical flagellar morphology, reduced mobility, and a slower bacterial growth rate compared with the wild-type strain. Fluorescence confocal microscopy revealed a decrease in the thickness of the biofilm formed by the ΔfliK strain, along with reductions in polysaccharide and DNA components. The deletion of fliK did not affect vacuolar toxicity or antibiotic resistance but did reduce the adhesive capacity of the bacterium to gastric mucosal cells. The deletion of the fliK gene significantly impairs H. pylori biofilm formation, leading to substantial decreases in biofilm components, bacterial growth, and adhesion capabilities. These findings underscore the importance of fliK in the pathogenicity of H. pylori.IMPORTANCEThe increasing antibiotic resistance of Helicobacter pylori has emerged as a global health concern, with biofilm formation serving as a crucial mechanism underlying this resistance. This study investigates the role of the fliK gene, which encodes the flagellar hook length control protein, in H. pylori biofilm formation. Furthermore, we examined the influence of fliK on H. pylori growth, motility, and cellular adhesion capabilities. Our findings elucidate the molecular mechanisms governing H. pylori biofilm formation and suggest potential therapeutic strategies for addressing H. pylori antibiotic resistance.

RevDate: 2025-03-23
CmpDate: 2025-03-21

Robinson RL, Fisk AT, S Crevecoeur (2025)

Temporal and Depth-Driven Variability of Pelagic Bacterial Communities in Lake Erie: Biofilm and Plankton Dynamics.

Environmental microbiology reports, 17(2):e70079.

Despite constituting an important component of freshwater ecosystems, biofilm assemblages have remained relatively understudied compared to plankton, especially in freshwater systems such as the western basin of Lake Erie (WBLE). This study therefore aimed to elucidate temporal and vertical shifts of microbial communities of planktonic and biofilm growth on artificial substrates in the WBLE water column at discrete depths, investigating the overlap of shared taxa between community types. Sequencing of the 16S rRNA gene revealed concurrent biofilm-plankton samples shared a low percentage (~10%) of amplicon sequence variants (ASVs) indicating distinct communities between free-living and substrate-attached bacteria. Plankton communities did not significantly differ between surface and bottom depths (1 and 8 m), whereas biofilm communities differed between upper (1-4 m) and lower (5-8 m) water columns. Temporal variation in community composition was observed in biofilm, with early periods (June-July) showing significant dissimilarity followed by compositional convergence in late summer onwards (August-October). With the expansion of artificial infrastructure in aquatic systems, there is novel substrate material to observe spatiotemporal patterns of microbial colonisation throughout the pelagic zone. These results demonstrate the complexity of bacterial biofilm communities from plankton in freshwater, providing insight into microbial assembly through temporal succession and across depth.

RevDate: 2025-03-22

Shirmohammadpour M, Mehrasbi MR, Noshiranzadeh N, et al (2025)

Investigation of the effect of anti-PIA/PNAG antibodies on biofilm formation in Escherichia coli.

Frontiers in microbiology, 16:1552670.

Polysaccharide Intercellular Adhesin (PIA), a surface polysaccharide produced by Staphylococcus aureus and Staphylococcus epidermidis, is a compelling target for opsonic and protective antibodies against these bacteria. Escherichia coli has recently made an exopolysaccharide called poly-β(1,6)-N-acetylglucosamine (PNAG), biochemically indistinguishable from PIA. This study investigated the effect of antibodies generated against PNAG on biofilm formation and the opsonization activity of secreted antibodies in Escherichia coli. Following purification and structural confirmation of PIA polysaccharide from producing Staphylococcus epidermidis, the ability to inhibit biofilm and the function of secreted antibodies for the mentioned polysaccharide were evaluated using semi-quantitative methods in a mouse model. Subsequently, the opsonic activity of antibodies targeting Escherichia coli strain ATCC 25922 was evaluated. The extracted polysaccharide was confirmed using FTIR, NMR, and colorimetric methods, and the results showed that the purified PIA induced protective antibodies with 40.48% opsonization properties in E. coli. The sera of the PIA-immunized groups showed a significant increase in antibody production and protective IgG titer levels compared to the control group. Also, the antibodies produced showed a substantial difference in inhibiting biofilm production in vitro compared to non-immunized serum. Antibodies directed against PIA with a lethality of 40.48% showed a significant effect on the absence of biofilm formation in E. coli. Despite the opsonic properties of the antibodies for E. coli, the simultaneous impact of these antibodies on infections caused by S. epidermidis and E. coli may have a role that requires further investigation and studies in animal models.

RevDate: 2025-03-20

Ottaviano E, Dei Cas M, Ancona S, et al (2025)

Pilocarpine inhibits Candida albicans SC5314 biofilm maturation by altering lipid, sphingolipid, and protein content.

Microbiology spectrum [Epub ahead of print].

UNLABELLED: Candida albicans filamentation and biofilm formation are key virulence factors tied to tissue invasion and antifungal tolerance. Pilocarpine hydrochloride (PHCl), a muscarinic receptor agonist, inhibits biofilm maturation, although its mechanism remains unclear. We explored PHCl effects by analyzing sphingolipid and lipid composition and proteomics in treated C. albicans SC5314 biofilms. PHCl significantly decreased polar lipid and ergosterol levels in biofilms while inducing phytoceramide and glucosylceramide accumulation. PHCl also induced reactive oxygen species and early apoptosis. Proteomic analysis revealed that PHCl treatment downregulated proteins associated with metabolism, cell wall remodeling, and DNA repair in biofilms to levels comparable to those observed in planktonic cells. Consistent with ergosterol reduction, Erg2 was found to be reduced. Overall, PHCl disrupts key pathways essential for biofilm integrity, decreasing its stability and promoting surface detachment, underscoring its potential as a versatile antifungal compound.

IMPORTANCE: Candida albicans filamentation and biofilm formation represent crucial virulence factors promoting fungus persistence and drug tolerance. The common eukaryotic nature of mammalian cells poses significant limitations to the development of new active nontoxic compounds. Understanding the mechanism underlying PHCl inhibitory activity on yeast-hypha transition, biofilm adhesion, and maturation can pave the way to efficient drug repurposing in a field where pharmaceutical investment is lacking.

RevDate: 2025-03-21

Mu WB, Yao LQ, Guo ZY, et al (2025)

Enhancing biofilm disruption and bactericidal efficiency using vancomycin-loaded microbubbles in sonodynamic therapy.

JAC-antimicrobial resistance, 7(2):dlaf045.

BACKGROUND: Periprosthetic joint infection (PJI) is a significant complication following arthroplasty, attributed to the biofilm formation. This study evaluates the effectiveness of vancomycin-loaded microbubbles (Van-MBs) in conjunction with ultrasound-targeted microbubble destruction (UTMD) on biofilm disruption and bactericidal efficiency.

METHODS: Van-MBs were prepared using the thin-film hydration method and characterized using microscopy, dynamic light scattering analysis, and high-performance liquid chromatography (HPLC). Confocal laser scanning microscopy (CLSM) was used to assess the penetration of Van and Van-MBs into biofilms. Biofilms were treated with Van, Van-MBs, UTMD, and Van-MBs + UTMD. CLSM and crystal violet staining were utilized to assess the morphology, viability, and biomass of the biofilms. Bacterial activity was examined through scanning electron microscopy (SEM) and plate counting, while gene expression was analyzed using quantitative real-time polymerase chain reaction (qRT-PCR).

RESULTS: The results demonstrated that Van-MBs penetrated deeper into methicillin-resistant Staphylococcus aureus (MRSA) biofilms compared with Van alone. The combination of Van-MBs and UTMD significantly reduced biofilm thickness, viability, and biomass. qRT-PCR analysis revealed that the Van-MBs + UTMD group exhibited lower transcription levels of the icaA gene, suggesting that the treatment disrupted biofilm formation by suppressing this key gene. SEM further confirmed the efficacy of the treatment, showing that Van-MBs + UTMD induced cytoplasmic shrinkage and separation of the outer and cytoplasmic membranes in MRSA cells, indicating substantial structural damage to the bacterial cells.

CONCLUSION: These findings demonstrate the potential of Van-MBs in combination with UTMD as an innovative approach to enhance antibiotic efficacy and eliminate biofilms in the treatment of PJI.

RevDate: 2025-03-21

Yoon JH, Song H, SY Lee (2025)

Biofilm formation, slime production, and antibiotic susceptibility properties of the Bacillus cereus group isolated from fresh vegetables in the Republic of Korea.

Food science and biotechnology, 34(6):1525-1531.

This study aimed to characterize the ability of the Bacillus cereus group isolated from conventionally, organically or pesticide-freely grown vegetables to form biofilms with regard to cell surface hydrophobicity (CSH), slime production, and antibiotic susceptibility. Cellular properties (biofilm formation, CSH, and slime production) were measured using an in vitro microplate assay with crystal violet staining, adhesion to hydrocarbons assay, and Congo red broth method, respectively. Consequently, 16, 16, and 16 B. cereus strains were isolated from conventionally, organically, and pesticide-freely grown vegetables, respectively, and 16 (33%) B. cereus isolates were highly biofilm-positive producers. CSH values dramatically varied, ranging from 19 to 74%, among the B. cereus isolates. Additionally, 9, 8, and 8 B. cereus strains isolated from conventionally, organically, and pesticide-freely grown vegetables, respectively, were identified to be slime-positive producers. According to the disc diffusion method, 19 and 41 B. cereus isolates were highly resistant to ampicillin and penicillin, respectively.

RevDate: 2025-03-19

Lu W, Guo X, Wu Y, et al (2025)

Particulate methane monooxygenase and cytochrome P450-induced reactive oxygen species facilitate 17β-estradiol biodegradation in a methane-fed biofilm.

Water research, 280:123501 pii:S0043-1354(25)00414-2 [Epub ahead of print].

Methane-fed biosystems have shown great potential for degrading various organic micropollutants, yet underlying molecular degradation mechanisms remain largely unexplored. In this study, we uncover the critical role of biogenic reactive oxygen species (ROS) in driving the degradation of 17β-estradiol (E2) within a methane-fed biofilm reactor. Metagenomic analyses confirm that aerobic methanotrophs, specifically Methylococcus and Methylomonas, are responsible for the efficient degradation of E2, achieving a degradation rate of 367.7 ± 8.3 μg/L/d. ROS scavenging in conjunction with enzyme inhibition experiments indicate that particulate methane monooxygenase (pMMO) and cytochrome P450 monooxygenase (CYP450) could generate hydroxyl radicals (•OH), which are the primary ROS involved in E2 degradation. Molecular dynamics simulations suggest that E2 can enter the active catalytic site of pMMO through electrostatic attraction. Four amino acid residues are found to form stable hydrogen bonds with E2, with a high binding free energy, indicating a high affinity for the substrate. Additionally, density functional theory calculations combined with transformation product analysis reveal that •OH targets carbon atoms on the benzene ring and the hydroxyl group attaches to the cyclopentane ring, primarily through hydrogen abstraction and hydroxylation reactions. This work provides critical insights into the mechanisms of E2 biodegradation in methane-fed systems and highlights the potential for optimizing microbial pathways to enhance the degradation of organic micropollutants from contaminated water.

RevDate: 2025-03-19

Liu Y, Hu L, Li Z, et al (2025)

Elucidating the biofilm formation process, microstructure and functional gene expression of Listeria monocytogenes in beef juice.

International journal of food microbiology, 434:111160 pii:S0168-1605(25)00105-9 [Epub ahead of print].

Listeria monocytogenes biofilm is recognized as a frequent cross-contamination source in the food industry, with raw beef and beef products as common food reservoirs. L. monocytogenes sequence types 9 (ST9) and ST8 are frequently isolated in meats and meat processing environment. In this study, beef juice was selected and compared to a laboratory medium (tryptone soy broth with 0.6 % yeast extract, TSB-YE). The purpose of this work was to investigate the effect of beef juice on the biofilm formation of ST9 and ST8 strains, including biofilm microstructure and modelling the biofilm formation process. Then the expression of biofilm functional genes in two culture media was also investigated. L. monocytogenes ST9 and ST8 can form a dense three-dimensional structure biofilm with multilayers of cells in beef juice after 48 h of incubation, but both strains formed a monolayer biofilm structure in TSB-YE. The ST9 strain developed more sessile cells on the stainless-steel surfaces than the ST8 strain under the same culture conditions. The Logistic model showed a good fit for with the biofilm formation process, and the estimated model parameters in beef juice and TSB-YE were considerably different. Under the same conditions, the maximum specific biofilm formation rate (μmax) in beef juice was higher than that in TSB-YE. This indicated that beef juice can facilitate the biofilm formation of L. monocytogenes, suggesting that the particles in beef juice act as a surface conditioner to support attachment. However, the maximum counts of L. monocytogenes biofilm formed on stainless steel coupon (Ymax) in beef juice was smaller than that in TSB-YE. The ST9 strain exhibited a stronger biofilm formation ability than the ST8 strain, and this was consistent with the scanning electron microscopy images. In the corresponding culture suspensions, the number of adherent cells increases with the number of planktonic cells. Moreover, the expression of biofilm functional genes was significantly different in the two culture media. Compared to biofilm cultured in TSB-YE, the expression of the agrA gene of biofilm in beef juice was significantly down-regulated for both the ST9 and the ST8 strains, and the expression of the inlB and the actA genes were dramatically up-regulated for the ST8 strain. Our results suggested that beef juice promotes biofilm formation of L. monocytogenes in meat processing and provide new insights into controlling biofilm.

RevDate: 2025-03-19
CmpDate: 2025-03-19

Fang Z, Yang X, L Shang (2025)

Microfluidic-derived montmorillonite composite microparticles for oral codelivery of probiotic biofilm and postbiotics.

Science advances, 11(12):eadt2131.

Oral delivery of probiotics has shown promising effects in modulating the gut microbiota and treating ulcerative colitis (UC). However, the therapeutic efficacy is restricted by gastrointestinal assaults, poor mucosal adhesion, and single therapeutic modality. Here, we developed acid-resistant, gut-environment-responsive composite microparticles based on microfluidic electrospray for the oral codelivery of probiotic [Lactobacillus acidophilus (LA)] biofilm and postbiotics (indole-3-propionic acid). Montmorillonite was selected for supporting biofilm formation due to its cation-exchange capability and clearly defined biosafety. The montmorillonite-LA biofilm was effectively protected by the microparticles and markedly improved the intestinal retention. Upon oral administration, the composite microparticles notably alleviated colitis in mice, including reducing the inflammatory response, improving intestinal barrier function, and modulating the gut microbiota. Consequently, the composite microparticles show high potential for enhancing probiotic delivery efficacy and present a promising strategy for UC treatment.

RevDate: 2025-03-19

Wang S, Wang Y, Cheng C, et al (2025)

PotF Affects the Antibacterial Activity of Plantaricin BM-1 Against Escherichia coli K12 by Modulating Biofilm Formation and Cell Membrane Integrity.

Probiotics and antimicrobial proteins [Epub ahead of print].

Plantaricin BM-1 exhibits antibacterial activity against Escherichia coli; however, the underlying mechanism remains unclear. This study aimed to investigate the function of PotF, a putrescine-binding protein, in regulating the antibacterial activity of plantaricin BM-1 against E. coli K12. The antibacterial activity of plantaricin BM-1 against E. coli K12 and JW0838 cells was assessed using growth curves. The differences in biofilm formation between the two E. coli strains were evaluated by crystal violet staining and confocal laser scanning microscopy. The effects of plantaricin BM-1 on E. coli morphology and cell membrane integrity were investigated by electron microscopy and lactate dehydrogenase release assays. Proteomics was used to screen for differentially expressed proteins (DEPs) that are potentially involved in regulating the antibacterial mechanism. The null mutation of potF enhanced the antibacterial effects of plantaricin BM-1 on E. coli, and caused a significant decrease (p < 0.05) in the biofilms of E. coli JW0838. The plantaricin disrupted the cell membrane of E. coli JW0838. Proteomic analysis revealed that potF mutation significantly affected several DEPs involved in biofilm formation. Plantaricin BM-1 exhibited significantly enhanced antibacterial activity against biofilm-associated gene mutants compared to wild-type E. coli K12. These findings enhance our understanding of the bacteriostasis of class IIa bacteriocins against Gram-negative microorganisms.

RevDate: 2025-03-20

Nayak D, Mishra AK, Biswas K, et al (2025)

Mangrove pneumatophores as biocatalysts for the fabrication of silver nanoparticles and their potential applications against biofilm formation and hepatic carcinoma.

Nanoscale advances [Epub ahead of print].

The current study demonstrates the biogenic synthesis of silver nanoparticles using the pneumatophores of Acanthus ilicifolius (AiP-AgNPs), which is cost-effective and biocompatible. A. ilicifolius possesses remarkable features to endure the harshest conditions for its entire life cycle and generates secondary metabolites for its sustainability in hostile mangrove ecosystems. The presence of a prominent UV-visible absorption band at 420 nm supported the distinct color change inference for the synthesized AiP-AgNPs. The size of the synthesized AiP-AgNPs was determined to be ∼15 nm through field emission-scanning electron microscopy (FE-SEM), transmission electron microscopy (cryo-TEM), and atomic force microscopy (AFM). The presence of secondary metabolites such as 2-bromo-1,1-dichloroethene, hemin and N-(sulfanylacetyl)-l-seryl-l-argininamide was indicated by prominent peaks in liquid chromatography, suggesting their probable roles in the synthesis of AgNPs. The synthesized AiP-AgNPs demonstrated a distinct zone of inhibition against Pseudomonas aeruginosa (15.33 mm), Vibrio cholerae (9.83 mm), and Bacillus subtilis (12 mm). They also exhibited concentration-dependent antioxidant activity in DPPH, nitric oxide, and hydrogen peroxide scavenging assays. The anticancer potential of the synthesized AiP-AgNPs against HepG2 hepatocarcinoma cells determined through MTT colorimetric assay and flow cytometry revealed their dose-dependent cytotoxicity with the occurrence of the sub-G0 phase (25.6%). Subsequent analysis using fluorescence microscopy, DNA damage, comet assay, and migration assay indicated that AiP-AgNPs hold significant potential and the ability to serve as a therapeutic candidate to pave the way for further in-depth investigations for pre-clinical and clinical research purposes.

RevDate: 2025-03-20

Modak S, Mane P, S Patil (2025)

A Comprehensive Phenotypic Characterization of Biofilm-Producing Coagulase-Negative Staphylococci: Elucidating the Complexities of Antimicrobial Resistance and Susceptibility.

Cureus, 17(2):e79039.

Background Coagulase-negative staphylococci (CoNS) have emerged as significant pathogens in nosocomial infections, particularly in bloodstream infections and individuals linked to embedded therapeutic devices. CoNS predominantly affects immunocompromised or debilitated patients. Additionally, individuals with medical indwelling devices, such as a catheter for the urinary tract, valves for the cardiovascular system, pacemakers, and prosthetic joints, should receive medical attention. As a result of the organism's evolving resistance to multiple antibiotics, managing CoNS infections is becoming increasingly challenging. The formation of biofilms is a key factor contributing to the pathogenicity and antimicrobial resistance of CoNS, complicating treatment efforts and the resolution of infections. Aim The aim of this study is to identify CoNS species, examine their biofilm production, and evaluate their resistance to antibiotics. Materials and methods A cross-sectional study was conducted on patients admitted to the Microbiology Department at Krishna Hospital, Karad. Clinical samples included the following: blood, pus, urine, sputum, endotracheal tube aspirate, high vaginal swab, and central venous catheter. Results The occurrence of coagulase-negative Staphylococcus across the range of clinical samples consisted of blood (61 isolates, 75.3%), pus (seven isolates, 8.6%), urine (six isolates, 7.4%), sputum (three isolates, 3.7%), endotracheal tubes (two isolates, 2.5%), and high vaginal swab and central venous catheter (one isolate (1.2%) each). The most often isolated species was Staphylococcus haemolyticus (35 isolates, 43.2%) followed by Staphylococcus epidermidis (22 isolates, 27.2%) and Staphylococcus hominis (12 isolates, 14.8%). We assessed the production of biofilms using Congo red agar, with 62 isolates (76.5%) demonstrating biofilm formation. Among these, S. haemolyticus was the predominant species exhibiting biofilm production, with 29 isolates (46.8%) testing positive. This was followed by S. epidermidis with 19 isolates (30.7%) and S. hominis with nine isolates (14.5%). Conclusion The results of antibiotic susceptibility tests revealed multidrug resistance, with most isolates showing a high level of susceptibility to linezolid (84%) and complete resistance to penicillin. These findings highlight the clinical implications of limited treatment options and the need for alternative therapies, such as linezolid, in managing infections caused by coagulase-negative staphylococci.

RevDate: 2025-03-21
CmpDate: 2025-03-19

Eidaroos NH, Algammal AM, Mohamaden WI, et al (2025)

Virulence traits, agr typing, multidrug resistance patterns, and biofilm ability of MDR Staphylococcus aureus recovered from clinical and subclinical mastitis in dairy cows.

BMC microbiology, 25(1):155.

BACKGROUND: Bovine mastitis caused by Staphylococcus aureus is considered a public health threat globally. Herein, we aimed to investigate the occurrence, agr typing, antimicrobial resistance patterns, biofilm production, and PCR-based detection of the virulence, biofilm, adhesion, and enterotoxins genes of S. aureus strains recovered from clinical and subclinical bovine mastitis.

RESULTS: The prevalence of S. aureus in the examined milk samples was 44.4%. Besides, 95% of the retrieved S. aureus strains were identified as MRSA. Herein, all the tested isolates were biofilm producers. PCR revealed that 85% of the retrieved S. aureus strains were positive for the agr I gene. Furthermore, the clfB, clfA, fnbB, fnbA, and cna genes were detected with a prevalence of 100%, 80%, 60%, 55%, and 30%, respectively. Also, all the tested S. aureus strains were positive for the coa gene (100%). Besides, 92.5% and 85% of the recovered strains harbored the lukF and spa genes, respectively. In addition, the prevalence of the hla, hlb, and hlg hemolysin genes was 70%, 50%, and 35%, respectively. Among the enterotoxin genes, the seb gene was detected in 30% of the tested strains. The prevalence of eno and icaA biofilm genes was 95% in the tested strains. Moreover, 15% of S. aureus strains were MDR to 8 antimicrobial agents and harbored the mecA, ermC, and ermB genes. As well, 12.5% of S. aureus strains were MDR to 8 antimicrobial agents and carried the mecA, ermC, ermB, tetK, and tetM genes. Also, 5% of S. aureus strains were XDR to 11 antimicrobial agents and carried the mecA, ermC, and ermB genes.

CONCLUSIONS: The existence of MDR and XDR MRSA strains in bovine milk is a public health hazard. The mecA, ermC, ermB, tetK, and tetM resistance genes and the coa, clfB, eno, icaA, lukF, spa, clfA, and hla virulence genes are commonly associated with the MDR and XDR MRSA strains. Moreover, the seb gene was the predominant enterotoxin gene in the MRSA strains recovered from milk.

RevDate: 2025-03-19
CmpDate: 2025-03-19

Xu Y, Wang L, Guo D, et al (2025)

Baohuoside I targets SaeR as an antivirulence strategy to disrupt MRSA biofilm formation and pathogenicity.

NPJ biofilms and microbiomes, 11(1):45.

The emergence of methicillin-resistant Staphylococcus aureus (MRSA) represents a critical global health challenge, making the SaeRS two-component system (TCS), a key regulator of S. aureus virulence, an ideal target for novel therapeutic approaches. In this study, virtual screening and thermal shift assays identified Baohuoside I (BI), a flavonol glycoside, as a potent inhibitor of the SaeR response regulator. BI significantly attenuated S. aureus pathogenicity without bactericidal effects, suppressing the expression of key virulence factors, such as hemolysin A (Hla) and Panton-Valentine leukocidin (PVL), while modulating immune evasion pathways. Additionally, BI disrupted biofilm formation, promoting the development of porous, less structured biofilms. Biochemical assays, including EMSA, CETSA, fluorescence quenching, and SPR, confirmed strong binding interactions between SaeR and BI. In vivo, BI demonstrated therapeutic efficacy in Galleria mellonella and rat MRSA models. These findings establish BI as a promising lead for nonbactericidal therapies to combat MRSA infections and mitigate resistance.

RevDate: 2025-03-19
CmpDate: 2025-03-19

Lazrak K, Tazart Z, Nothof M, et al (2025)

Assessment of the short-term salinity effect on algal biofilm through field transfer in the Drâa river (Southeastern Morocco) using metabarcoding and morphological analyses.

Environmental monitoring and assessment, 197(4):424.

As a result of human activities and climate change, salinity levels have risen considerably in many of the world's rivers, particularly in arid and semi-arid areas. This freshwater salinization primarily affects microalgal biofilms, the primary producers in aquatic ecosystems. This study is aimed at assessing short-term salinity effects on benthic algal communities in the Drâa river, Morocco, using biofilm field-transfer experiments. Artificial substrates were initially positioned in three sites of the Drâa river with different salinity levels. After 4 weeks, the biofilm-colonized substrates were transferred from one site to another in both directions. After a further 4 weeks, the algal biofilms were sampled to assess their community composition, alpha and beta diversity, and biomass in response to salinity changes using molecular and morphological analyses. Transferring biofilms from low-salt to saline sites significantly reduced biomass but increased it in the reverse transfer. Eliminating certain sensitive microalgae taxa decreased alpha diversity in all biofilm transfers from low-salt sites to the most saline one. Biofilm diversity increased significantly in the opposite transfer. Significant changes were observed in biofilm composition when transferred into saltwater showing an increase in halophilic and euryhaline diatom taxa. In contrast, transfers from saltwater sites to low-salt sites increased oligohaline diatom species. As a result, increasing salinity reduced algal biomass and diversity, while decreasing salinity caused the opposite effect. These results can help predict the salinity variations effects on benthic algae, highlight the potential dangers of increased river salinization, and promote salinity reduction in aquatic ecosystems subject to secondary salinization.

RevDate: 2025-03-18

Shental-Isaacs M, Horev G, CG Dosoretz (2025)

Evaluation of biofilm carrier colonisation in a deammonification moving-bed biofilm reactor.

Environmental technology [Epub ahead of print].

This study focused on the evaluation and characterisation of carrier colonisation of a deammonification moving-bed biofilm reactor (dMBBR) at a low carrier-inoculation ratio (≤5%v/v), applying multiple methodologies. The dMBBR (5 L working volume) was filled with Aqwise carriers (50%v/v filling ratio) and fed with synthetic feedstock. Carrier colonisation was differentially tracked using grey colour for new carriers and white colour for pre-colonised seed carriers. The reactor operated for 190 days at a nitrogen loading of 125-140 gN/m[3]/d. Multivariant heatmap analysis of the process parameters indicated stable deammonification performance from day 85 onwards albeit some occasional malfunctions occurred, with NH4[+] and total nitrogen removal rates amounting to 85% and 61%, respectively. Biofilm development on new carriers, evaluated by bulk density measurements via pycnometry, proved to be a reliable, simple, and non-destructive methodology. Anammox of genus Candidatus Brocadia and ammonia oxidising bacteria of genus Nitrosomonas were well established on the new carriers, in line with theoretical and empirical specific activity tests. This multi-parameter evaluation provides a broad insight into deammonification biomass development on the carriers and may assist in shortening the start-up period of dMBBRs.

RevDate: 2025-03-18
CmpDate: 2025-03-18

Liu T, Lin J, X Zheng (2025)

[Role of antibiotic delivery system targeting bacterial biofilm based on ε-poly- L-lysine and cyclodextrin in treatment of bone and joint infections].

Zhongguo xiu fu chong jian wai ke za zhi = Zhongguo xiufu chongjian waike zazhi = Chinese journal of reparative and reconstructive surgery, 39(3):362-369.

OBJECTIVE: To explore the mechanism of antibiotic delivery system targeting bacterial biofilm with linezolid (LZD) based on ε-poly- L-lysine (ε-PLL) and cyclodextrin (CD) (ε-PLL-CD-LZD), aiming to enhance antibiotic bioavailability, effectively penetrate and disrupt biofilm structures, and thereby improve the treatment of bone and joint infections.

METHODS: ε-PLL-CD-LZD was synthesized via chemical methods. The grafting rate of CD was characterized using nuclear magnetic resonance. In vitro biocompatibility was evaluated through live/dead cell staining after co-culturing with mouse embryonic osteoblast precursor cells (MC3T3-E1), human umbilical vein endothelial cells, and mouse embryonic fibroblast cells (3T3-L1). The biofilm-enrichment capacity of ε-PLL-CD-LZD was assessed using Staphylococcus aureus biofilms through enrichment studies. Its biofilm eradication efficacy was investigated via minimum inhibitory concentration (MIC) determination, scanning electron microscopy, and live/dead bacterial staining. A bone and joint infection model in male Sprague-Dawley rats was established to validate the antibacterial effects of ε-PLL-CD-LZD.

RESULTS: In ε-PLL-CD-LZD, the average grafting rate of CD reached 9.88%. The cell viability exceeded 90% after co-culturing with three types cells. The strong biofilm enrichment capability was observed with a MIC of 2 mg/L. Scanning electron microscopy observations revealed the effective disruption of biofilm structure, indicating potent biofilm eradication capacity. In vivo rat experiments demonstrated that ε-PLL-CD-LZD significantly reduced bacterial load and infection positivity rate at the lesion site (P<0.05).

CONCLUSION: The ε-PLL-CD antibiotic delivery system provides a treatment strategy for bone and joint infections with high clinical translational significance. By effectively enhancing antibiotic bioavailability, penetrating, and disrupting biofilms, it demonstrated significant anti-infection effects in animal models.

RevDate: 2025-03-18

Rooney LJP, Marshall A, Tunney MM, et al (2025)

Phenylboronic Acid-Modified Polyethyleneimine: A Glycan-Targeting Anti-Biofilm Polymer for Inhibiting Bacterial Adhesion to Mucin and Enhancing Antibiotic Efficacy.

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

Bacterial biofilms present significant therapeutic challenges due to their resistance to conventional antimicrobial treatment. Mucins typically serve as a protective barrier against pathogens, yet certain bacteria, such as Pseudomonas aeruginosa (P. aeruginosa), can exploit these glycoproteins as attachment sites for biofilm formation. This study introduces boronic acid-functionalized polyethyleneimine (PEI-BA) as a promising antibiofilm agent that effectively blocks bacterial adhesion to mucin-rich surfaces. Through the multivalent presentation of boronic acid groups, PEI-BA reversibly forms boronate ester bonds with mucin glycans, creating a protective barrier. Our findings show that PEI-BA prevents bacterial attachment through a nonbactericidal mechanism, potentially reducing the risk of resistance development. Notably, PEI-BA synergizes with a conventional antibiotic, tobramycin, significantly enhancing biofilm inhibition compared to either treatment alone. Systematic evaluation of PEI-BA formulations identified optimal functionalization levels, balancing glycan-binding capability with solubility. From a biomaterials design perspective, we demonstrate how rational polymer modification can transform a potent but cytotoxic antimicrobial agent (i.e., PEI) into a safe and effective antibiofilm material, opening further possibilities for managing biofilm-associated infections in clinical settings. This work establishes boronic acid-based nanomaterials as promising candidates for biofilm prevention and antibiotic enhancement, particularly in conditions like cystic fibrosis, where mucin-bacterial interactions contribute to disease progression.

RevDate: 2025-03-19

Li H, Zhang S, Li Q, et al (2025)

The Role of Yinqiao Powder in Modulating Pseudomonas aeruginosa Biofilm and Virulence Factors.

Infection and drug resistance, 18:1405-1414.

PURPOSE: It is now understood that the primary challenges in treating Pseudomonas aeruginosa (P. aeruginosa) infections are the secretion of multiple virulence factors, the formation of biofilm, and the emergence of multi-drug resistance. Small regulatory RNAs (sRNAs) and quorum sensing (QS) play an important role in regulating bacterial biofilms and multiple virulence factors, presenting potential targets for novel anti-P. aeruginosa therapies. Yinqiao Powder has demonstrated inhibitory activity against various bacteria and viruses. The objective of this study was to elucidate the precise mechanism of Yinqiao Powder's impact on P. aeruginosa virulence and to ascertain its clinical utility.

METHODS: First, the effects of Yinqiao Powder on various virulence factors of P. aeruginosa were assessed through virulence phenotype experiments, including biofilm formation assay, pyocyanin production assay, rhamnolipid assay, and motility assay. Then, a cytotoxicity assay was used to evaluate the effect of P. aeruginosa treated by Yinqiao Powder on cells. Finally, an RT-qPCR assay was used to detect the effects of Yinqiao Powder on QS system and virulence-related gene expression.

RESULTS: This study revealed that sub-minimum inhibitory concentration (sub-MIC) levels of Yinqiao Powder significantly inhibit biofilm formation, swarming motility, pyocyanin and rhamnolipid production in a dose-dependent manner. The cytotoxicity assay also confirmed that Yinqiao Powder weakened the cytotoxicity of P. aeruginosa. Furthermore, Yinqiao Powder was found to modulate the P. aeruginosa sRNA-QS-virulence network. Specifically, it repressed the lasI, the rhlI, and sRNA P27 while upregulating sRNA PhrD. Additionally, the phzA and pqsA genes, associated with pyocyanin and rhamnolipid/biofilm regulation, respectively, were repressed by Yinqiao Powder.

CONCLUSION: Yinqiao Powder effectively inhibits QS system-related regulatory genes, sRNAs, biofilm formation, swarming motility, pyocyanin and rhamnolipid production at specific concentrations. These results support the potential of Yinqiao Powder as a quorum-sensing inhibitor.

RevDate: 2025-03-18
CmpDate: 2025-03-18

Yadav P, Shyam Kumar Mishra , Shrestha S, et al (2025)

Multidrug-Resistance and Biofilm Formation among Acinetobacter baumannii Isolated from Clinical Specimens.

Journal of Nepal Health Research Council, 22(4):662-669.

BACKGROUND: Acinetobacter baumannii has emerged as a problematic pathogen due to its ability to become resistant to antibiotics and form biofilms. The aim of this study was to explore antibiotic resistance and biofilm formation, and examine any correlation between these in Acinetobacter baumannii isolates.

METHODS: This was a cross-sectional study conducted at the 750-bed Tribhuvan University Teaching Hospital in Nepal. Identification and antibiotic sensitivity of Acinetobacter baumannii isolates were performed following American Society for Microbiology guidelines. Different β-lactamases were detected by standard phenotypic tests. The microtiter plate method was used to screen strains of their ability to form biofilms.  Results: Out of total 18,343 clinical samples processed, 4,249 (23.1%) showed bacterial growth. A. baumannii comprised of 4.7% of the total bacterial growth. Multidrug-resistant (MDR) was exhibited by 97.5% of Acinetobacter baumannii isolates. All multidrug-resistant Acinetobacter baumannii isolates were resistant to cephalosporins and carbapenems; however, they were sensitive to polymyxins. Only few isolates showed sensitivity to sulbactam-containing antibiotics (15.4-29.2%), fluoroquinolones (1.0-7.2%), aminoglycosides (2.6-5.6%), and cotrimoxazole (4.1%). Extended-spectrum-beta-lactamase (ESBL), metallo-beta-lactamase (MBL), Klebsiella pneumoniae carbapenemase (KPC) and AmpC production were found in 54.9%, 73.3%, 41.5% and 14.9% isolates, respectively. Among all tested isolates, 192 were able to produce biofilms, with 83.1% being classified as strong biofilm producers. Those strains that were resistant to gentamicin were more likely to produce biofilms (P<0.05). ESBL, MBL, KPC and AmpC were seen in 51.8%, 71.6%, 43.8% and 16.0% of strong biofilm producers respectively.

CONCLUSIONS:   Only polymyxins were effective against Acinetobacter baumannii. Carbapenemase producers were generally strong biofilm producers, and gentamicin resistant strains were more likely to produce biofilms. The findings of this study may help to understand antibiotic-resistance mechanisms and provide valuable information in the treatment of MDR Acinetobacter baumannii infections.

RevDate: 2025-03-18

Chong CSC, Lau YY, Michels PAM, et al (2025)

Insights into biofilm-mediated mechanisms driving last-resort antibiotic resistance in clinical ESKAPE pathogens.

Critical reviews in microbiology [Epub ahead of print].

The rise of antibiotic-resistant bacteria poses a grave threat to global health, with the ESKAPE pathogens, which comprise Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa and Enterobacter spp. being among the most notorious. The World Health Organization has reserved a group of last-resort antibiotics for treating multidrug-resistant bacterial infections, including those caused by ESKAPE pathogens. This situation calls for a comprehensive understanding of the resistance mechanisms as it threatens public health and hinder progress toward the Sustainable Development Goal (SDG) 3: Good Health and Well-being. The present article reviews resistance mechanisms, focusing on emerging resistance mutations in multidrug-resistant ESKAPE pathogens, particularly against last-resort antibiotics, and describes the role of biofilm formation in multidrug-resistant ESKAPE pathogens. It discusses the latest therapeutic advances, including the use of antimicrobial peptides and CRISPR-Cas systems, and the modulation of quorum sensing and iron homeostasis, which offer promising strategies for countering resistance. The integration of CRISPR-based tools and biofilm-targeted approaches provides a potential framework for managing ESKAPE infections. By highlighting the spread of current resistance mutations and biofilm-targeted approaches, the review aims to contribute significantly to advancing our understanding and strategies in combatting this pressing global health challenge.

RevDate: 2025-03-17

Lee J, Shin WR, Kim YH, et al (2025)

Targeted Inhibition of Oral Biofilm Formation Using Phage-Derived High-Affinity Peptides.

Journal of biotechnology pii:S0168-1656(25)00067-7 [Epub ahead of print].

Dental caries, commonly known as tooth decay, poses a significant oral health challenge affecting individuals of all age groups. While dietary factors play a role, tooth decay primarily results from the activity of various oral bacteria that form biofilms in the oral cavity. In this study, we employed the phage display technique to identify high-affinity peptides capable of binding specifically to three oral bacteria strains: Streptococcus mutans, Streptococcus oralis, and Lactobacillus casei. Four selected peptides underwent binding affinity testing for each target bacterium, revealing that three of them exhibited specific binding capabilities, effectively inhibiting biofilm formation. This study demonstrates the efficacy of engineered phages in identifying high-affinity peptides that selectively target oral bacteria. These peptides hold promise for preventing oral biofilm formation, a significant contributor to oral diseases and dental caries. This innovative approach opens doors to novel therapeutic strategies for addressing oral health issues. The findings may spur further research into the utilization of phages and peptides as potential anti-biofilm agents, potentially revolutionizing the field of oral health.

RevDate: 2025-03-17

Leite de Oliveira Rosa I, de O Ferreira E, AP Vieira Colombo (2025)

Molecular detection of toxigenic Clostridioides difficile in subgingival biofilm of severe periodontitis.

Anaerobe pii:S1075-9964(25)00018-6 [Epub ahead of print].

OBJECTIVES: The oral cavity is the main gateway for the entry of C. difficile spores to the digestive tract. In conditions of poor oral hygiene and periodontal diseases, the dysbiotic oral microbiota may be a reservoir for several human pathogens. Here, we explored the prevalence of C. difficile in the oral microbiota of patients with severe periodontitis by the molecular detection of species specific genes.

METHODS: Subgingival biofilm, saliva and/or feces from 659 patients with gingivitis, periodontitis and no periodontal diseases were screened for the tpi and toxin A/B genes specific for C. difficile by multiplex PCR. Differences among groups were sought by the Chi-square test.

RESULTS: The overall frequency of C. difficile tpi gene was 29%, with a high detection of tcdB gene (44.8%). Patients with periodontitis showed a greater prevalence of this gene in the biofilm than individuals with gingivitis and periodontal health (p=0.001), particularly at more severe stages of disease (p<0.05). No toxin genes were detected in feces or biofilm from healthy patients, whereas >70% of the biofilm from patients with periodontal diseases were positive for these genes (p<0.001). Detection of C. difficile tpi gene in oral/fecal samples correlated with periodontal inflammation (p<0.05). A modest intra-individual agreement between tpi gene detection in feces and saliva was found within periodontitis patients (Kappa=0.314; p=0.003).

CONCLUSION: The high frequency of the C. difficile specific genes tpi and tcdB in the dysbiotic subgingival biofilm of advanced periodontitis could support the presence of this species in this niche.

RevDate: 2025-03-17

Ma Z, Zhang Z, Fu S, et al (2025)

Integration of moving bed biofilm reactor and gravity-driven membrane bioreactor for decentralized domestic wastewater treatment: Efficiency and mechanistic insights.

Bioresource technology pii:S0960-8524(25)00365-7 [Epub ahead of print].

This study investigated the coupling of a moving bed biofilm reactor (MBBR) with a gravity-driven membrane bioreactor (GDMBR) for the long-term treatment of decentralized domestic wastewater. The results indicated that the introduction of MBBR significantly improved the stable flux of GDMBR (by 8 %-22 %) and enhanced its resistance to the shock loading of influent quality. Such improvements were attributed to the reduction in extracellular polymeric substances (EPS) (by 30 %-46 %), positive modifications to the membrane biofilm, and improvements in microbial richness and community composition. Compared to GDMBR control, the start-up period of MBBR-GDMBR systems was reduced by 6-15 days, owing to the beneficial effects of MBBR-derived microorganisms, which promoted microbial evolution within the GDMBR membrane biofilm, thereby accelerating the stabilization of filtration performance. Overall, this study provides valuable insights into shortening the start-up period of the GDMBR process, enhancing its resistance to external shock loads, and improving flux levels.

RevDate: 2025-03-17

Wan L, Kimball K, Cusick A, et al (2025)

Achromobacter xylosoxidans: An uncommon scalp infection leading to alopecia and biofilm formation.

Diagnostic microbiology and infectious disease, 112(2):116797 pii:S0732-8893(25)00120-8 [Epub ahead of print].

Achromobacter xylosoxidans is an emerging opportunistic pathogen causing respiratory and systemic infections, mainly in immunocompromised individuals. Cutaneous infections remain uncommon. We present a unique case of a 60-year-old immunocompetent female with a persistent, pruritic, and malodorous scalp infection for over a year, leading to alopecia and biofilm formation, complicating treatment by increasing antibiotic resistance. Despite lacking typical risk factors, wound culture identified A. xylosoxidans with susceptibility to trimethoprim-sulfamethoxazole, which led to successful treatment alongside surgical debridement. This case highlights the need for clinicians to consider A. xylosoxidans in differential diagnoses of unusual skin infections, especially when biofilm formation is evident, and underscores the importance of targeted antibiotic therapy due to this pathogen's multidrug resistance.

RevDate: 2025-03-17

Moon Y, Hong J, Choi S, et al (2025)

Biofilm Growth on Different Materials Used in Contemporary Femoral Head Prosthesis: An In Vitro Study.

Journal of clinical medicine, 14(5):.

Background/Objectives: Periprosthetic joint infection (PJI) primarily results from bacterial biofilms adhering to prosthetic surfaces, making treatment challenging without prosthesis removal. This in vitro study aims to investigate whether the materials used in contemporary femoral head prosthesis influences bacterial biofilm development. Methods: Femoral head prostheses made of three different materials-cobalt-chrome, oxinium, and ceramic-were inoculated with either Staphylococcus aureus or Pseudomonas aeruginosa in separate experiments, with each pathogen tested independently. The samples were cultured under shaking conditions at 37 °C for 96 h to promote biofilm formation. Scanning electron microscopy (SEM) was used to confirm the presence of biofilms, and adherent biofilms were quantified by counting colony-forming units (CFUs) after sonication. Additionally, crystal violet staining was performed to assess biofilm distribution on the femoral head surfaces. Statistical analyses compared CFU counts across the different materials. Results: The mean CFU counts for S. aureus were 7.6 × 10[5] ± 9.7 × 10[4] for cobalt-chrome, 6.9 × 10[5] ± 3.6 × 10[5] for oxinium, and 1.1 × 10[6] ± 3.0 × 10[5] for ceramic femoral head prostheses. For P. aeruginosa, the CFU counts were 2.3 × 10[6] ± 7.2 × 10[5], 3.7 × 10[6] ± 2.5 × 10[6], and 2.2 × 10[6] ± 8.9 × 10[5], respectively. Regardless of the bacterial strain, differences among the three materials were within one log range, and no statistical significance was observed. While biofilms were confirmed using SEM, limited adherence was observed on the bearing surface, with the biofilm predominantly localized in the taper hole. Conclusions: The findings suggest that the material used in contemporary femoral head prostheses has minimal impact on bacterial biofilm formation. Surgeons' choice of femoral head prosthesis material should base their material selection on factors other than PJI prevention.

RevDate: 2025-03-17

de Castro PA, Akiyama DY, Pinzan CF, et al (2025)

Aspergillus fumigatus secondary metabolite pyripyropene is important for the dual biofilm formation with Pseudomonas aeruginosa.

mBio [Epub ahead of print].

The human pathogenic fungus Aspergillus fumigatus establishes dual biofilm interactions in the lungs with the pathogenic bacterium Pseudomonas aeruginosa. Screening of 21 A. fumigatus null mutants revealed seven mutants (two G protein-coupled receptors, three mitogen-activated protein kinase receptors, a Gα protein, and one histidine kinase receptor) with reduced biofilm formation, specifically in the presence of P. aeruginosa. Transcriptional profiling and metabolomics analysis of secondary metabolites produced by one of these mutants, ΔgpaB (gpaB encodes a Gα protein), showed GpaB controls the production of several important metabolites for the dual biofilm interaction, including pyripyropene A, a potent inhibitor of mammalian acyl-CoA cholesterol acyltransferase. Deletion of pyr2, encoding a non-reducing polyketide synthase essential for pyripyropene biosynthesis, showed reduced A. fumigatus Δpyr2-P. aeruginosa biofilm growth, altered macrophage responses, and attenuated mouse virulence in a chemotherapeutic murine model. We identified pyripyropene as a novel player in the ecology and pathogenic interactions of this important human fungal pathogen.IMPORTANCEAspergillus fumigatus and Pseudomonas aeruginosa are two important human pathogens. Both organisms establish biofilm interactions in patients affected with chronic lung pulmonary infections, such as cystic fibrosis (CF) and chronic obstructive pulmonary disease. Colonization with A. fumigatus is associated with an increased risk of P. aeruginosa colonization in CF patients, and disease prognosis is poor when both pathogens are present. Here, we identified A. fumigatus genetic determinants important for the establishment of in vitro dual A. fumigatus-P. aeruginosa biofilm interactions. Among them, an A. fumigatus Gα protein GpaB is important for this interaction controlling the production of the secondary metabolite pyripyropene. We demonstrate that the lack of pyripyropene production decreases the dual biofilm interaction between the two species as well as the virulence of A. fumigatus in a chemotherapeutic murine model of aspergillosis. These results reveal a complete novel role for this secondary metabolite in the ecology and pathogenic interactions of this important human fungal pathogen.

RevDate: 2025-03-18
CmpDate: 2025-03-17

Deng Y, Zheng J, Li J, et al (2025)

NIR light-driven nanomotor with cascade photodynamic therapy for MRSA biofilm eradication and diabetic wound healing.

Theranostics, 15(8):3474-3489.

Background: Diabetic wounds infected with methicillin-resistant Staphylococcus aureus (MRSA) are challenging to heal due to biofilm formation, which impairs conventional antibiotics with limited penetration and severe side effects. Near-infrared (NIR)-driven nanomotors with autonomous motion and photothermal effects show promise for antibacterial therapy but often lack targeted specificity. Lysostaphin (Ly), an enzyme targeting bacterial cell walls, offers excellent potential against drug-resistant MRSA. Methods: A novel NIR-driven CSIL nanomotor has fabricated by co-loading indocyanine green (ICG) and lysostaphin onto spinous yolk-shell structured C/SiO2@C nanoparticles. The autonomous motion, biofilm penetration, and antibacterial efficacy of CSIL nanomotors are evaluated in vitro, while their biofilm eradication and wound healing performance are assessed in an MRSA-infected diabetic mouse model using a cascade photodynamic therapy (CPDT) strategy. Results: CSIL nanomotors exhibit photothermal and photodynamic properties with MRSA-targeting specificity. They can effectively eradicate MRSA biofilms both in vitro and in vivo, suppress virulence and biofilm-related genes, thus promoting diabetic wound healing by shaping a microenvironment dominated by M2 macrophages. The CPDT strategy is able to avoid excessive ROS production and thermal damage, enabling safe and effective therapy. Conclusion: CSIL nanomotors, with integrated photothermal, photodynamic, and MRSA-targeting properties, represent a novel, efficient and targeted approach to antibacterial therapy in diabetic wounds, offering significant advantages over conventional antibiotics.

RevDate: 2025-03-18
CmpDate: 2025-03-17

Han Z, Li Y, Zhan X, et al (2025)

A versatile nanoplatform with excellent biofilm permeability and spatiotemporal ROS regulation for peri-implantitis treatment.

Theranostics, 15(8):3490-3516.

Rationale: Dental implant restoration is essential for rehabilitating dentition defects. However, peri-implantitis (PI) seriously threatens the long-term stability of implants. Treating PI requires the complete eradication of plaque biofilm and the meticulous modulation of inflammatory responses. Antibacterial photodynamic therapy (aPDT) presents a promising potential in the antibacterial realm. Nonetheless, traditional aPDT for PI faces challenges such as inadequate biofilm penetration and distribution of photosensitizers, as well as a lack of precise bacteria targeting. Moreover, the excessive ROS generated by aPDT will aggravate the oxidative stress of peri-implant tissues, and this issue cannot be neglected. Methods: The CuTA-Por@ε-PL nanoplatforms (CPP NPs) were synthesized and characterized using dynamic light scattering, transmission electron microscopy, and dye probes in detail. The antibacterial and anti-inflammatory activities of CPP NPs were evaluated both in vitro and in vivo. Moreover, the in vivo therapeutic efficacy was successively analyzed through micro-CT, hematoxylin and eosin staining, Masson's staining, immunofluorescence staining, and colony formation units (CFU), among other techniques. Results: Porphyrin (Por), CuTA nanozyme with SOD/CAT activities, and ε-Polylysine (ε-PL) were combined to fabricate CPP NPs via a straightforward approach. The notable positive charge of CPP NPs facilitated biofilm penetration, distribution and precise bacteria targeting. Then, irradiation with a 660 nm laser triggered a ROS burst for biofilm elimination. After aPDT, CPP NPs scavenged the residual ROS and modulated host immunity by regulating macrophage polarization. As a result, CPP-treated groups demonstrated the most outstanding antibacterial and anti-inflammatory performance in the rat PI model. Conclusions: Given the pathogenesis of PI, this strategy rationally designed a multifunctional NP with antibacterial and anti-inflammatory functions via spatiotemporal ROS regulation. It provides a potentially novel approach for PI treatment, which may have a profound impact on improving the prognosis of patients with PI and advancing the field of implant dentistry.

RevDate: 2025-03-18

Van Roy Z, T Kielian (2025)

Immune-based strategies for the treatment of biofilm infections.

Biofilm, 9:100264.

Biofilms are bacterial communities surrounded by a polymeric matrix that can form on implanted materials and biotic surfaces, resulting in chronic infection that is recalcitrant to immune- and antibiotic-mediated clearance. Therefore, biofilm infections present a substantial clinical challenge, as treatment often involves additional surgical interventions to remove the biofilm nidus, prolonged antimicrobial therapy to clear residual bacteria, and considerable risk of treatment failure or infection recurrence. These factors, combined with progressive increases in antimicrobial resistance, highlight the need for alternative therapeutic strategies to circumvent undue morbidity, mortality, and resource strain on the healthcare system resulting from biofilm infections. One promising option is reprogramming dysfunctional immune responses elicited by biofilm. Here, we review the literature describing immune responses to biofilm infection with a focus on targets or strategies ripe for clinical translation. This represents a complex and dynamic challenge, with context-dependent host-pathogen interactions that differ across infection models, microenvironments, and individuals. Nevertheless, consistencies among these variables exist, which could facilitate the development of immune-based strategies for the future treatment of biofilm infections.

RevDate: 2025-03-18

Baek J, Lee J, Jeong YJ, et al (2025)

Inhibition of Salmonella Typhimurium Biofilm Formation, Adhesion, and Invasion by Whey Beverage Supplemented with Triticum dicoccum (Farro) Enzyme.

Food science of animal resources, 45(2):648-661.

Triticum dicoccum (Farro) an ancient wheat species has recently gained attention for its exceptional health benefits. However, research on its antibacterial and anti-biofilm properties remains limited. Additionally, a growing trend has been observed in releasing enriched or fortified whey beverages to enhance their functionality. Therefore, this study aimed to investigate the inhibitory effects of whey beverages supplemented with enzyme-rich fermented farro (WF) on Salmonella Typhimurium biofilm formation and explore the underlying mechanisms. Treatment with WF significantly reduced biofilm formation and viability of S. Typhimurium. Moreover, WF decreased the bacterial adhesion to and invasion of human intestinal epithelial cells. WF also inhibited gene expression associated with motility and initial adhesion in S. Typhimurium, as well as genes involved in quorum sensing (QS), in a concentration-dependent manner. Furthermore, WF suppressed the production of the QS signaling molecule autoinducer-2 in a similar concentration-dependent manner. Consequently, our findings indicate that the addition of enzyme-rich fermented farro to whey beverage enhances anti-biofilm activity, which is probably attributed to its antimicrobial effects, inhibition of initial adhesion, and QS reduction. These findings offer a promising basis for developing fortified dairy beverages that can enhance food safety and promote human health.

RevDate: 2025-03-17

Islam MH, Hosna Ara M, Khan MA, et al (2025)

Preparation of Cellulose Nanocrystals Biofilm from Coconut Coir as an Alternative Source of Food Packaging Material.

ACS omega, 10(9):8960-8970.

The current perspective emphasizes on the synthesis of a biofilm from cellulose nanocrystals (CNC) of coconut coir for the development of sustainable packaging materials as an alternative source of plastic. The biofilm was prepared by a solvent-casting method and investigated by various analytical techniques. Of them, surface morphology was observed by SEM, suggesting a crystalline rod shape with particle size of 104-318 nm and diameter of 15-70 nm. However, CNC was incorporated with starch at various ratios ranging from 10:0 to 1:9; the ratio 6:4 of CNC and the binder maximized the mechanical properties of the polymer. In the presence of a plasticizer and a cross-linker, the film possessed high tensile strength (38.4 ± 1.57 MPa) and elongation (8.2 ± 0.39%) compared to commercially available polyethylene (9.84 ± 0.32 MPa and 23 ± 0.74%). The biofilm possessed a great extent of cross-link structure, divulging through the change of contact angle (92°), surface morphology (rough surface), crystallinity (45.36%), water vapor transmission rate (427 g/m[2]/day), and thermal stability from 232 to 258 °C. The degree of deterioration was assessed by the soil burial test (30-45 days), highlighting the environmental compatibility of the film.

RevDate: 2025-03-17

Alves GB, Calderari MRDCM, Fonseca END, et al (2025)

Photodynamic Inactivation Mediated by Endogenous Porphyrins of Corynebacterium diphtheriae in Planktonic and Biofilm Forms.

ACS omega, 10(9):9177-9186.

Photodynamic inactivation (PDI) has emerged as a promising approach to combat bacterial infections by using light activation of photosensitizers to induce microbial death. This study investigated the potential of endogenous porphyrins produced by Corynebacterium diphtheriae as photosensitizers for PDI. Qualitative analysis revealed the presence of porphyrins in all strains studied, with coproporphyrin III predominating. The addition of 5-aminolevulinic acid (ALA) enhanced porphyrin production, as evidenced by increased fluorescence intensity. In addition, high-performance liquid chromatography with diode array and mass spectrometry detection analyses confirmed the presence of coproporphyrin III and protoporphyrin IX in all strains, and the ALA supplementation did not alter the porphyrin profiles. Quantitative analysis showed that strain-dependent coproporphyrin III levels were significantly increased with ALA supplementation. Additionally, biofilm formation was positively correlated with porphyrin production, suggesting a role for porphyrins in biofilm formation. Photoinactivation experiments showed that the strains responded differently to light exposure, with ALA supplementation, reducing the time required for significant CFU/mL reduction. In addition, biofilm survival exceeded planktonic cell survival, highlighting the challenges posed by biofilm structures with regard to PDI efficacy. Despite the variable responses observed, all strains exhibited a reduction in viability following light exposure, demonstrating the potential of endogenous porphyrins for antimicrobial photoinactivation applications.

RevDate: 2025-03-16

Dong J, Zhang S, Chan YK, et al (2025)

Vacancies-rich Z-scheme VdW heterojunction as H2S-sensitized synergistic therapeutic nanoplatform against refractory biofilm infections.

Biomaterials, 320:123258 pii:S0142-9612(25)00177-2 [Epub ahead of print].

Encapsulated in a self-produced negatively charged extracellular polymeric substance (EPS) matrix, the wound infected bacterial biofilms exhibit formidable resistance to conventional positively charged antibiotics and host's immune responses, which can undoubtedly lead to persistent infections and lethal complications. Nevertheless, developing efficacious strategies to root out stubborn biofilm and promote tissue regeneration still remains a challenge. To resolve this dilemma, a versatile vacancies-rich Z-scheme MoSSe Van der Waals heterojunction (MoSSe VdW HJ) is rationally fabricated as nanoplatform for hydrogen sulfide (H2S)-sensitized synergistic therapy of wound bacterial biofilm infection. The rich anion vacancies and Z-scheme heterostructure make the fabricated MoSSe VdW HJ can effectively augment H2S, localized hyperthermia, and reactive oxygen species production under the stimulation of biofilm microenvironments (BME) and irradiation of 808 nm near-infrared (NIR) light. Therefore, MoSSe VdW HJ is capable to integrate H2S gas, chemodynamic, photothermal, and photodynamic therapies to effectively destroy eDNA and polysaccharides in the EPS matrix, thereby breaching the biofilm barrier to eradicate bacteria and facilitate wound healing. The synergistic strategy exhibits superior anti-biofilm and wound repair effects both in vivo and in vitro, thus providing guideline for the development of BME and NIR light activated synergistic therapeutics to fight against refractory biofilm infections.

RevDate: 2025-03-16

Dong KY, Yang CX, Pang JL, et al (2025)

Antibiotics shape the core microbial community distribution between floc and biofilm in an endogenous partial denitrification system: Insight from metabolic pathway.

Water research, 280:123491 pii:S0043-1354(25)00404-X [Epub ahead of print].

The response mechanism of microorganisms in partial denitrification (PD) system under antibiotic stress, particularly microbial energy metabolism and electron transfer, remain inadequately understood. This knowledge gap hinders the establishment of ecological links between microbial dynamics and macro-level reactor performance. To address this, moving bed biofilm reactors were employed to investigate the dynamic changes of microbial community and metabolism under sulfadiazine (SDZ) and ciprofloxacin (CIP) stress. Results showed that dosing 2 mg/L SDZ or CIP accelerated nitrite accumulation, achieving this milestone 15 days earlier than in the control group. At the end of the operational phase, nitrate removal efficiencies reached 90.3 ± 18.3 % (Control), 83.5 ± 16.2 % (SDZ-treated) and 93.9 ± 12.4 % (CIP-treated), with nitrate-to nitrite-transformation rates of 61.3 ± 12.7 %, 65.6 ± 13.1 % and 58.0 ± 21.2 %, respectively. The abundances of energy supply related genes, i.e., sucC and PK were higher in the CIP-treated group, while those in the other two groups were similar. The promoted tricarboxylic acid cycle and glycolysis led to NADH and ATP accumulation, accelerating nitrogen metabolism and benefiting early nitrite accumulation in the antibiotic-stressed system. More importantly, increasing antibiotics concentration from 2 mg/L to 4 mg/L induced selective migration of Thauera from floc to biofilm (abundance in floc reduced to < 2.01 %). Metagenomic sequencing indicated that the higher abundance of narGHI in biofilms, compared to flocs, was crucial for maintaining stable PD performance under antibiotic stress. The electron transport related genes, such as IDH1, DLD and DLAT, were more abundant in biofilms than in flocs after SDZ and CIP addition. These findings provide a theoretical basis for understanding the response mechanism of PD consortia to antibiotic.

RevDate: 2025-03-16

Marín A, Feijóo P, Carbonetto B, et al (2025)

Long-term monitoring of biofilm succession unveils differences between biodegradable and conventional plastic materials.

Marine pollution bulletin, 214:117820 pii:S0025-326X(25)00295-4 [Epub ahead of print].

A vast amount of plastic waste enters the ocean every year and the Mediterranean Sea is particularly affected by this issue. Biodegradable polymers like poly(lactic acid) (PLA) and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), may help mitigate this problem. We investigated bacterial biofilm development and succession on these polymers over one year in the Western Mediterranean Sea. Scanning electron microscopy (SEM) and confocal laser scanning were used to examine microbial colonization and surface erosion, while bacterial community abundance and composition were assessed through culture plate counting and 16S rRNA gene amplicon sequencing. SEM revealed significant surface erosion on PHBV, indicative of microbial degradation, while PLA exhibited minor and irregular erosion. Culture-based quantification showed higher bacterial colonization on PHBV compared to PLA, suggesting that PHBV provides a more favourable surface for bacterial attachment Amplicon sequencing of the 16S rRNA gene revealed high bacterial diversity, with 17,781 operational taxonomic units across all samples. Proteobacteria, Bacteroidota, and Planctomycetota were the dominant phyla, with the Shannon index consistently exceeding 8, corroborating the bacterial diversity across all materials. Temporal shifts in bacterial community composition were significant, with exposure time explaining 29.8 % of the variation, suggesting biofilm succession as a key factor shaping microbial assemblages. While polymer type had a limited impact on bacterial composition, PHBV biofilms exhibited greater bacterial abundance and diversity compared to PLA. This study highlights PHBV's role in shaping biofilms and its relevance in assessing biodegradable plastics in marine environments. Understanding microbial interactions with bioplastics is crucial for evaluating their environmental impact and degradation dynamics.

RevDate: 2025-03-15

Senthil Kumar SA, Praveenkumar K, Jothipandian S, et al (2025)

Nanoscale Surface Modifications on Titanium Plates- A Strategy to Mitigate MRSA Biofilm-mediated Implant Infections: a pilot Study.

Microbial pathogenesis pii:S0882-4010(25)00206-2 [Epub ahead of print].

Orthopaedic implant infections pose a major threat after implantation. Biofilms of pathogenic bacteria resistant to antibiotics cause biomaterial infections. Methicillin-resistant Staphylococcus aureus (MRSA) is one of the prevalent biofilm-forming pathogens associated with implant infection in high proportion. Loss of effectiveness of antibiotics against these drug-resistant pathogens demands alternative approaches to surmount this crisis. Various strategies involving antibiotics, biocides, and metal ions are employed as the prohibiting steps of biofilm formation. Hence, to prevent biofilm formation and infections caused by biofilms formed over the orthopaedic implants, we involved laser micro-machining to modify the surface of the Titanium (Ti) plate, the most widely used implant material. Interestingly, we found that the laser-peening process generated widespread nanosized pores and micro-roughness to the surface of the Ti plate. Laser-peened Ti plate reduced the adhesion of MRSA over the metal surface and also retained its capacity to inhibit biofilm formation, which was confirmed with scanning electron microscopy (SEM). The biofilm assays like quantification of biofilm by crystal violet, determination of colony forming unit from biofilm formed over the control and laser-peened Ti plates showed that the laser-peened Ti plate significantly reduced the adherence of biofilm-forming MRSA. Moreover, the genes responsible for biofilm adhesion were found to be downregulated which was confirmed by qPCR. From our results, it was found that laser-peened Ti implants would be an alternative strategy to prevent biofilm-mediated infection on orthopaedic implant material.

RevDate: 2025-03-15

Wu T, Zhao P, Pan P, et al (2025)

Biofilm-disrupting DNA nanomedicines for targeted elimination of resistant wound microbiota.

Journal of controlled release : official journal of the Controlled Release Society, 381:113618 pii:S0168-3659(25)00235-4 [Epub ahead of print].

Biofilms are complex bacterial communities that significantly hinder the treatment of chronic and recurrent infections by enhancing bacterial virulence and conferring resistance to antimicrobial therapies. To address this challenge, an intelligent DNA nanomedicine has been engineered to dismantle biofilms and target resistant bacteria, offering an innovative solution for chronic wound infections. These nanomedicines initiate biofilm degradation through in situ generation of potent oxidative radicals, enabling deep biofilm penetration and precise bacterial targeting. Utilizing aptamers for specific bacterial identification, the nanomedicines concentrate therapeutic agents directly at infection sites. The combined effect of severe oxidative stress and sustained silver ion release ensures a continuous, focused assault on pathogens, effectively eradicating resistant bacteria. This strategy demonstrated broad-spectrum efficacy against both Gram-positive and Gram-negative bacteria, significantly enhancing wound healing in a diabetic infection model. By integrating intelligent bacterial eradication with modulation of the wound microenvironment, this approach presents a promising solution for overcoming biofilm-associated resistance and advancing chronic wound infection treatment.

RevDate: 2025-03-14

Nirmala B, BJ Omar (2025)

Microbial Biofilm Detection and Differentiation by Dual Staining Using Maneval's Stain.

Bio-protocol, 15(5):e5228.

Microbial biofilms are structured communities of microorganisms embedded in a self-produced extracellular matrix, adhering to surfaces. These biofilms enhance bacterial resistance to antibiotics, immune responses, and environmental stress. Current microscopy techniques, such as scanning electron microscopy (SEM), confocal laser scanning microscopy (CLSM), and fluorescence microscopy, are commonly used to visualize and differentiate biofilms. However, their high cost and complexity often render them impractical. In contrast, simpler methods like crystal violet and Congo red staining are limited in distinguishing bacterial cells from the biofilm matrix. This study introduces a cost-effective, dual-staining method using Maneval's stain to visualize and differentiate microbial biofilms. It requires only basic equipment and minimal reagents, making it ideal for routine use in clinical diagnosis and microbial research. Key features • This dual-staining method differentiates bacterial cells, biofilm matrix, and capsules in a single stain. • This method applies to both bacterial and fungal biofilm. • This method requires no specialized training or equipment, with the entire process completed within 30-45 min. • Stained slides can be stored for extended periods (months) without degradation.

RevDate: 2025-03-14

Ketteler HM, Johnson EL, McGlennen M, et al (2025)

A simulated microgravity biofilm reactor with integrated microfabricated sensors: Advancing biofilm studies in near-space conditions.

Biofilm, 9:100263.

Studying biofilms in a microgravity environment currently relies on one of two scenarios, collecting planktonic aggregates in rotating wall vessels or performing experiments in the microgravity environment of space on the International Space Station. While informative techniques, both have their limitations when studying surface-attached microbial communities. A simulated microgravity biofilm reactor (SMBR) was developed to study biofilms in microgravity, coupled with the integration of microfabricated sensors for internal system monitoring. The establishment of simulated microgravity was demonstrated through computational fluid dynamic modelling revealing low fluid shear stress conditions (<1 mPa) throughout the reactor and on the wall surface. Microfabricated resistance temperature devices integrated in the reactor walls confirmed the capability for continuous sensor measurements during operation with the ability to perform traditional microbiology analyses on the sensor surface following an experiment. Microbiological analyses established that there were no significant differences in biofilm growth between sensor and wall surfaces within the reactor. With the integration of defined sampling surfaces, the SMBR allows for in-depth biofilm analysis in a repeatable and accessible manner allowing for a greater understanding of the effects of microgravity on biofilm.

RevDate: 2025-03-13

Yang T, Li H, Yu R, et al (2025)

Lactoferrin-alginate-pectin composite hydrogel: Enhancing Lactobacillus plantarum B072 survival, density and biofilm formation.

International journal of biological macromolecules pii:S0141-8130(25)02534-6 [Epub ahead of print].

This research established a novel ternary composite hydrogel matrix composed of lactoferrin (Lf), sodium alginate (SA), and high ester pectin (HEP) for encapsulation Lactobacillus plantarum B072. The synergy of these components creates a robust, stable, and protective environment for the encapsulation of L. plantarum B072. The hydrogel beads exhibited high a encapsulation efficiency of 76.43 %, excellent mechanical strength, and thermal stability, while promoting biofilm formation, significantly increasing bacterial density to 9.57 log CFU/mL, and enhancing acid resistance, thereby providing an effective physical barrier against gastrointestinal stress. Hydrogen bonds and electrostatic repulsion play a critical role in maintaining the compact structure of the hydrogel, while hydrogen bonds and hydrophobic interactions further enhance its structural stability. Molecular docking analysis demonstrated that LF-casein forms stable complexes with HEP by binding to specific active sites, including LEU-708, GLY-342, ARG-268, LEU-266, ARG-361, ASN-349, LEU-404, MET-622, and PRO-153. In simulated gastrointestinal digestion, the encapsulated L. plantarum B072 achieved a survival of 7.42 log CFU/mL, outperforming free bacteria. This work provides a new strategy for the development of probiotic delivery systems and the improvement of product stability.

RevDate: 2025-03-13

Zhang Y, Ren M, Su J, et al (2025)

Simultaneous removal of carbamazepine, nitrate, and copper in a biofilm reactor filled with FeMn-modified ceramsite.

Journal of hazardous materials, 491:137871 pii:S0304-3894(25)00785-X [Epub ahead of print].

Mixtures of pollutants are a significant challenge for conventional wastewater treatment processes. In the present work, the potential of a biofilm reactor to simultaneously remove nitrate (NO3[-]-N), carbamazepine (CBZ), and copper ions (Cu[2+]) was evaluated. The reactor was filled with FeMn-modified ceramsite (CS@FeMn) and inoculated with the strains of Cupriavidus sp. HY129 and Pantoea sp. MFG10, which contributed to the redox cycling of Mn. Under optimum conditions with the HRT, C/N and pH of 9.0 h, 2.0, and 7.0, respectively, the bioreactor incorporating CS@FeMn demonstrated a significant increase in nitrogen removal capacity compared to the CS carrier, achieving a NRE of 96.7 %. Moreover, the removal efficiencies of CBZ and Cu[2+] reached the values of 91.8 % and 85.6 %, respectively. The experimental results indicated that the removals of CBZ and Cu[2+] were closely associated with microbial activity, involving the combined effects of microbial metabolism, adsorption of CS@FeMn, and bioprecipitation. Analyses through high-throughput sequencing and KEGG pathway revealed that the presence of CBZ and Cu[2+] reshaped the structure of microbial community within the bioreactor, driving the regulation of functional genes and nitrogen metabolism-related genes to maintain metabolic stability. These findings indicated that the CS@FeMn bioreactor system presents an effective solution for simultaneously addressing multiple pollutants in water treatment, achieving high efficiencies in NO3[-]-N, CBZ, and Cu[2+] removal.

RevDate: 2025-03-13

Zhang ZM, Zhao SY, Liu WQ, et al (2025)

Hybrid Molecules of Benzothiazole and Hydroxamic Acid as Dual-Acting Biofilm Inhibitors with Antibacterial Synergistic Effect against Pseudomonas aeruginosa Infections.

Journal of medicinal chemistry [Epub ahead of print].

The ubiquitous opportunistic pathogen Pseudomonas aeruginosa (P. aeruginosa) causes biofilm-associated drug-resistant infections that often lead to treatment failure. Targeting the bacterium's quorum sensing (QS) and iron homeostasis presents a promising strategy to combat biofilm formation. This study synthesized benzothiazole-conjugated hydroxamic acid derivatives as dual-acting biofilm inhibitors, and compound JH21 was identified as the hit compound with potent submicromolar biofilm inhibitory activity (IC50 = 0.4 μM). Further mechanistic studies demonstrated not only that the production of virulence was decreased through mainly inhibiting QS system but also that JH21 competed for iron with the high-affinity siderophore pyoverdine, inducing iron deficiency and inhibiting biofilm. Moreover, JH21 significantly enhanced the efficacy of tobramycin and ciprofloxacin by 200- and 1000-fold, respectively, in a mouse wound infection model. These results emphasized the feasibility of dual-acting biofilm inhibitors against resistant P. aeruginosa infections and the potential of JH21 as a novel antibacterial synergist.

RevDate: 2025-03-14

Hong S, Lu H, Tian D, et al (2025)

Discovery of triazole derivatives for biofilm disruption, anti-inflammation and metal ion chelation.

Frontiers in chemistry, 13:1545259.

In the face of bacterial hazards to human health and resistance to multiple antibiotics, there is an urgent need to develop new antibiotics to meet the challenge. In this paper, the triazolyl heterocyclic (3-amino-1,2,4-triazole, D) was synthesised efficiently using thiourea as starting material. Finally, the end product E was obtained by aldehyde-amine condensation reaction and the structures of all compounds were determined by spectral analysis. In vitro antimicrobial activity showed that E10 had a MIC of 32 μg/mL against the tested Escherichia coli and 16 μg/mL against the tested Staphylococcus aureus strain. Meanwhile, E10 has a good anti-biofilm effect. Antibacterial mechanism studies have shown that E10 has a good membrane targeting ability, thus disrupting cell membranes, leading to leakage of intracellular proteins and DNA and accelerating bacterial death. In terms of anti-inflammation, E10 dose-dependently inhibits the levels of inflammatory factors NO and IL-6, which deserves further exploration in the treatment of asthma. The study of metal ion removal capacity showed that the synthesised triazole derivatives have high capacity to remove heavy metals Pb[2+], Cd[2+], Ca[2+], Mg[2+], Fe[3+],Cr[3+] and Al[3+] in the range of 42%-60%.

RevDate: 2025-03-13

Han SL, Wang J, Wang HS, et al (2025)

Extracellular Z-DNA Enhances Cariogenicity of Biofilm.

Journal of dental research [Epub ahead of print].

Extracellular DNA (eDNA) is one of the core components of the extracellular matrix (ECM) in biofilms and provides attachment sites for microbes and other ECM components. However, little is known about the functions and underlying mechanisms of eDNA in the cariogenicity of dental plaque biofilms. A recent study demonstrated that conformational diversity of eDNA exists in biofilms, and the transition of eDNA from right-handed (B-DNA) to left-handed (Z-DNA) is associated with the structural stability and pathogenicity of biofilms. Caries-related biofilm is a complex multispecies microenvironment. The presence and biological function of the conformational transition of eDNA within this biofilm have not been previously reported. In this study, we found that extracellular Z-DNA is widely present in carious tissues and cariogenic biofilm, especially Streptococcus mutans, indicating its possible role in the occurrence and activity of dental caries. The content of extracellular Z-DNA showed species heterogeneity. The modulation of Z-DNA formation affected the level of extracellular polysaccharide. Increased formation of Z-DNA substantially strengthened the cariogenicity of the biofilm by increasing DNase resistance, structural density, and acid production. These insights provide a new perspective to understand the underlying function of the conformation transition of eDNA in promoting carious lesions, as well as a possible anti-biofilm strategy targeting extracellular Z-DNA.

RevDate: 2025-03-15
CmpDate: 2025-03-13

Guo M, Ling X, He L, et al (2025)

NapR Regulates the Expression of Phosphoserine Aminotransferase SerC to Modulate Biofilm Formation and Resistance to Serine Stress of Mycobacteria.

International journal of molecular sciences, 26(5):.

Mycobacterium tuberculosis is a formidable pathogen capable of establishing persistent infections within macrophages. To survive and thrive within the host environment, it has evolved intricate regulatory networks, including a diverse array of transcription factors that enable adaptation to various stresses encountered within the host. However, the mechanisms by which transcription factors regulate biofilm formation in M. tuberculosis remain incompletely understood. This study aimed to investigate the role of serC, encoding phosphoserine aminotransferase, and its regulation by NapR, a transcription factor, in mycobacterial physiology. NapR regulates serC through directly binding to its promoter. Notably, the regulatory effect and corresponding phenotypes vary due to distinct binding affinities of NapR for the serC promoter in different mycobacterial species. In Mycobacterium smegmatis, NapRMsm positively regulates biofilm formation, growth on solid media, and the transition from microcolonies to microcolonies by activating serCMsm. In the BCG vaccine, on the contrary, NapRBCG represses serCBCG, thus negatively regulating colony size and alleviating the growth inhibition caused by high concentrations of serine. Furthermore, proteomic analysis suggested NapR serves as a global transcriptional regulator in BCG vaccine strains by simultaneously modulating four metabolic pathways. These findings underscore the complex and strain-specific regulatory mechanisms governing serine metabolism in mycobacteria and provide valuable insights into the interplay between metabolism, gene regulation, and bacterial physiology.

RevDate: 2025-03-15
CmpDate: 2025-03-13

Bierowiec K, Delmar A, Karwańska M, et al (2025)

Comparison of Staphylococcus pettenkoferi Isolated from Human Clinical Cases and Cat Carriers Regarding Antibiotic Susceptibility and Biofilm Production.

International journal of molecular sciences, 26(5):.

Staphylococcus pettenkoferi (S. pettenkoferi) is a rare opportunistic bacterium not commonly found in healthy individuals or animals. S. pettenkoferi has increasing clinical significance in both veterinary and human medicine due to its multidrug resistance and biofilm-forming ability. This study analyzed 12 isolates of S. pettenkoferi collected from humans and cats and identified them using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and 16S rRNA and partial rpoB gene sequencing. All of the S. pettenkoferi were phenotypically resistant to penicillin, and almost all (except one human strain) were resistant to methicillin. Antibiotic susceptibility testing revealed a high prevalence of multidrug resistance in all human strains with frequent resistance to β-lactams, macrolides, and tetracyclines. A comparative analysis of human and feline isolates indicated the presence of shared resistance genes such as blaZ, mecA, and ermA. Biofilm production varied across isolates, with more potent biofilm formation abilities observed at elevated temperatures (39 °C) and time (48 h). These findings underscore the potential zoonotic risks of S. pettenkoferi and its role in managing multidrug-resistant infections.

RevDate: 2025-03-13
CmpDate: 2025-03-13

Komaniecka I, Żebracki K, Mazur A, et al (2025)

The Absence of a Very Long Chain Fatty Acid (VLCFA) in Lipid A Impairs Agrobacterium fabrum Plant Infection and Biofilm Formation and Increases Susceptibility to Environmental Stressors.

Molecules (Basel, Switzerland), 30(5):.

The Agrobacterium fabrum C58 is a phytopathogen able to infect numerous species of cultivated and ornamental plants. During infection, bacteria genetically transform plant cells and induce the formation of tumours at the site of invasion. Bacterial cell wall components play a crucial role in the infection process. Lipopolysaccharide is the main component of Gram-negative bacteria's outer leaflet of outer membrane. Its lipophilic part, called lipid A, is built of di-glucosamine backbone substituted with a specific set of 3-hydroxyl fatty acids. A. fabrum incorporates a very long chain hydroxylated fatty acid (VLCFA), namely 27-hydroxyoctacosanoic acid (28:0-(27OH)), into its lipid A. A. fabrum C58 mutants deprived of this component due to mutation in the VLCFA's genomic region, have been characterised. High-resolution mass spectrometry was used to establish acylation patterns in the mutant's lipid A preparations. The physiological properties of mutants, as well as their motility, ability to biofilm formation and plant infectivity, were tested. The results obtained showed that the investigated mutants were more sensitive to environmental stress conditions, formed a weakened biofilm, exhibited impaired swimming motility and were less effective in infecting tomato seedlings compared to the wild strain.

RevDate: 2025-03-13

Almuhayya S, Alshahrani R, Alsania R, et al (2025)

Biofilm Formation on Three High-Performance Polymeric CAD/CAM Composites: An In Vitro Study.

Polymers, 17(5):.

Reinforced polymeric materials are investigated as novel non-metal alternatives for prosthetic frameworks. This study examined the adherence of Streptococcus mutans to three high-performance polymeric (HPP) composites focusing on their microstructural composition, wettability, and surface roughness. Three CAD/CAM HPP composites [two fiber-reinforced composites, CarboCad (CC) and TRINIA (TR), and one ceramic-reinforced polyether ether ketone, DentoPEEK (PK)], were sectioned into ten beam- and ten plate-shaped specimens from each material. Surface properties (n = 10) were analyzed by water wettability and roughness measurements (Ra and Rz). The biofilm adherence was determined by calculating the number of S. mutans through colony-forming units (CFUs). Representative images were obtained using a confocal laser scanning microscope (CLSM) and scanning electron microscopy (SEM). The data were analyzed using Welch one-way ANOVA and Dunnett T3 post hoc tests. The results showed significant differences in roughness (Ra) across the materials, ranked from highest to lowest as follows: TR, 0.231 µm; CC, 0.194 µm; and PK, 0.161 µm (p = 0.0001). The contact angle averages varied from 51.36° to 91.03°, with PK exhibiting the highest wettability (p = 0.0012). However, S. mutans adherence was markedly reduced in PK (1.96 CFU/mm[2], p = 0.0001) in comparison to TR and CC (2.86 and 2.98 CFU/mm[2], respectively). Consequently, the fiber-reinforced composites (CC and TR), despite their low wettability, exhibited greater susceptibility for bacterial adherence than the smoother and more wettable PK, highlighting the substantial impact of their surface roughness and microstructural variability.

RevDate: 2025-03-12

Lin C, Zhang N, Liang Y, et al (2025)

Roles of flgJ in biofilm formation of Vibrio alginolyticus.

Journal of applied microbiology pii:8071976 [Epub ahead of print].

AIM: This study aimed to investigate the role of two flgJ genes in flagellar assembly and biofilm regulation in Vibrio alginolyticus.

METHODS AND RESULTS: To investigate the functions of the flgJ, overexpression and gene knockout techniques were employed. Overexpression of flgJ1 enhanced the strain's growth capacity, leading to a rapid bacterial concentration that initiated biofilm formation. Additionally, this overexpression caused different aggregation patterns at various growth stages. In contrast, the knockout of flgJ1 resulted in the loss of the flagellum, reduced motility, and decreased growth. Interestingly, under static culture conditions, the flgJ1 mutant strain aggregated and grew at the air-liquid interface, accompanied by an increased concentration of intracellular c-di-GMP, which ultimately also promoted biofilm formation. Thus, both the absence and overexpression of flgJ1 led to increased biofilm formation. On the other hand, both gene knockout and overexpression of flgJ2 lacked any response under the experimental conditions.

CONCLUSION: FlgJ1 plays a crucial role in flagellar assembly and motility, while flgJ2 has been found to be non-functional. Both overexpression and knockout of the flgJ1 gene result in increased biofilm formation through distinct regulatory mechanisms. These findings enhance our understanding of the role of flgJ gene in regulating biofilm formation.

RevDate: 2025-03-13

He L, He X, Zhang Y, et al (2025)

Enhanced dissimilatory nitrate reduction to ammonium and electron transfer mechanisms in bidirectional electron transfer biofilm constructed by iron phthalocyanine.

Bioresource technology, 426:132381 pii:S0960-8524(25)00347-5 [Epub ahead of print].

Bidirectional electron transfer biofilms (BETB) could efficiently reduce nitrate without accumulating nitrite, representing a promising biological electrochemical denitrification technology. This study utilized iron phthalocyanine modified carbon felt (FePc-CF) to enrich electroactive bacteria, constructing a long-term stable FePc-BETB. Its nitrate removal rate reached 91%, far exceeding the traditional nitrate-reducing biocathode (45%) and Con-BETB (46%). The dissimilatory nitrate reduction to ammonium (DNRA) dominated nitrate reduction in FePc-BETB, consuming 35% of the total electrons. Additionally, FePc-BETB effectively reduced the accumulation of NO2[-]-N and N2O. Electrochemical analysis demonstrated FePc-BETB exhibited stronger electrochemical activity and electron transfer capability. Mediated electron transfer (MET) enhanced by increased extracellular humic acid in FePc-BETB favored the electron supplement for nitrate removal. The relative abundance of nrfA, marker of the DNRA, increased significantly. This study provided new insights into regulating denitrification and DNRA pathways and treating nitrate wastewater lacking electron donors.

RevDate: 2025-03-12

Liaqat I, Qaiser I, Aftab MN, et al (2025)

Anti-biofilm potential of some fish probiotics, alone and in combination with antibiotics against isolated aquaculture pathogens; a preliminary data.

Microbial pathogenesis pii:S0882-4010(25)00162-7 [Epub ahead of print].

This study aims to isolate and identify both diseased and healthy fish pathogens of Ctenopharyngodon idella, Labeo rohita and Oreochromis niloticus and assess their antibacterial and biofilm supressing activities against fish pathogens. It explores their potential to inhibit and degrade biofilms, serving as an alternative to antibiotics in aquaculture while enhancing fish health and disease resistance. Furthermore, the research endeavors to assess the biofilm degradation potential of antibiotics and probiotics, both individually and in combination. The biofilm-forming potential of pathogens was assessed both qualitatively and quantitatively using the Congo red assay, cover slip, and test tube methods. Additionally, genomic sequencing through 16S rRNA ribotyping revealed the species level identification of four pathogenic and twelve probiotic strains. Three pathogens, Staphylococcus sciuri, Pseudomonas aeruginosa, and Staphylococcus xylosus, showed significant biofilm formation at day 5, while the pathogen Niallia circulans expressed maximum biofilm formation on day 7. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of antibiotics were evaluated against pathogenic strains. Antibiotic susceptibility testing revealed significant inhibition zones. MIC and MBC values ranged from 0.10 mg/ml to 85.00 mg/ml, with the agar well and disk diffusion methods demonstrating strong inhibitory effects against the pathogenic strains. Notably, fish probiotics either alone or in combination with antibiotics exhibited significant inhibition and anti-biofouling activity across three different concentrations (1/2 MIC, 1MIC, 2XMIC). The biofilm eradication values were statistically significant (p < 0.005). The findings affirm the effectiveness of the antibiotics (ampicillin, levofloxacin, kanamycin and oxytetracycline) and probiotics (Bacullus altitudinis, Bacillus pumilus, Mammaliicoccus sciuri) employed in preventing and dispersing biofilms formed by isolated fish pathogens (S. sciuri, P. aeruginosa and N. circulans). The current study explores the use of probiotics to enhance fish immunity, reduce disease risk without promoting antibiotic resistance, and disrupt pathogenic biofilms to control infections. Unlike antibiotics, probiotics are biodegradable and eco-friendly, minimizing harm to aquatic ecosystems and beneficial microbes.

RevDate: 2025-03-12

Zhang Q, E J, Guo X, et al (2025)

Sucrose improve Lactiplantibacillus plantarum LIP-1's tolerance to heat by increasing biofilm production.

International journal of food microbiology, 434:111136 pii:S0168-1605(25)00081-9 [Epub ahead of print].

Optimizing the carbon source to increase biofilm production and thus boost the heat tolerance of strains is a promising strategy. However, related research is scarce. This study investigated the effects of varying glucose and sucrose amounts added to MRS medium on biofilm production and heat tolerance by Lactiplantibacillus plantarum LIP-1. Transcriptomic, proteomic, and metabolomic approaches were combined to analyze the intrinsic mechanism underlying the sucrose-induced increase in biofilm production. We then investigated the protective role of the biofilm for the strain. Compared with the control group (2 % glucose), biofilm production in the experimental group (2 % glucose+2 % sucrose) increased by 27 %, and after heat treatment (75 °C for 40 s), the experimental group demonstrated a 38 % increase in heat tolerance. Multiomic results unveiled that biofilm synthesis-related metabolism pathways were altered in the experimental group compared with the control group. When the expression of key genes and the enzymes they encode(sacA, metC, mccB, and CTH) was upregulated, L-homocysteine was synthesized. According to metabolomics results, the L-homocysteine content in the experimental group increased to twice that in the control group. This resulted in a 37 % increase in the extracellular protein content of biofilms. The biofilm inhibition test confirmed that this increase in extracellular protein content was the primary factor augmenting the strain's heat tolerance. The findings suggested that adding sucrose to MRS medium for boosting biofilm production is a viable technical approach that enhances cell tolerance to heat.

RevDate: 2025-03-12
CmpDate: 2025-03-12

Sun B, Guo J, Hao B, et al (2025)

Liquid-bodied antibiofilm robot with switchable viscoelastic response for biofilm eradication on complex surface topographies.

Science advances, 11(11):eadt8213.

Recalcitrant biofilm infections pose a great challenge to human health. Micro- and nanorobots have been used to eliminate biofilm infections in hard-to-reach regions inside the body. However, applying antibiofilm robots under physiological conditions is limited by the conflicting demands of accessibility and driving force. Here, we introduce a liquid-bodied antibiofilm robot constructed by a dynamically cross-linked magnetic hydrogel. Leveraging the viscoelastic response of the robot enables it to adapt to complex surface topographies such as medical meshes and stents. Upon actuation, the robot can mechanically destroy the biofilm matrix, chemically deactivate bacterial cells, and collect disrupted biofilm debris. The robot's antibiofilm performance is studied in vitro and demonstrated on a medical mesh and a biliary stent. Tracking and navigation under endoscopy and x-ray imaging in an ex vivo porcine bile duct are demonstrated. Last, in vivo antibiofilm treatment is conducted by indwelling infected stents into mice's abdominal cavity and clearing the biofilm infection using the proposed robot.

RevDate: 2025-03-12

PLOS One Editors (2025)

Retraction: The biofilm formation and antibiotic resistance of bacterial profile from endotracheal tube of patients admitted to intensive care unit in southwest of Iran.

PloS one, 20(3):e0320615 pii:PONE-D-25-09569.

RevDate: 2025-03-12

Zhang S, He W, Dong J, et al (2025)

Tailoring Versatile Nanoheterojunction-Incorporated Hydrogel Dressing for Wound Bacterial Biofilm Infection Theranostics.

ACS nano [Epub ahead of print].

Wound-infected bacterial biofilms are protected by self-secreted extracellular polymer substances (EPS), which can confer them with formidable resistance to the host's immune responses and antibiotics, and thus delays in diagnosis and treatment can cause stubborn infections and life-threatening complications. However, tailoring an integrated theranostic platform with the capability to promptly diagnose and treat wound biofilm infection still remains a challenge. Herein, a versatile erbium-doped carbon dot-encapsulated zeolitic imidazolate framework-8 (Er:CDs@ZIF-8) nanoheterojunction (C@Z nano-HJ) is tailored and incorporated into gelatin methacrylate/poly(N-hydroxyethyl acrylamide) (GelMA/PHEAA)-based tough and sticky hydrogel dressing (GH-C@Z) to achieve wound biofilm infection-integrated theranostic application. Stimulated by the acidic microenvironment of the biofilm, the turn-on response of the C@Z in the dressing assists the biofilm infection monitoring by exhibiting cyan fluorescence. Meanwhile, C@Z can effectively destroy the EPS barrier and accomplish photothermal-photodynamic-ion interference synergistic antibacterial therapy under near-infrared light. Furthermore, after the effective eradication of biofilm, the potent antioxidant properties of released Er:CDs allow the dressing to attenuate reactive oxygen species and mitigate inflammatory responses, which finally promote collagen deposition and neovascularization to accelerate wound healing. Overall, this tailored wound dressing provides insight into the development of versatile diagnostic and therapeutic platforms for bacterial biofilm infections.

RevDate: 2025-03-13

Rivet C, Elliott JT, Gunn JR, et al (2025)

Rabbit model of a biofilm-contaminated, percutaneous orthopaedic endoprosthesis.

OTA international : the open access journal of orthopaedic trauma, 8(1 Suppl):e384.

Preclinical models of osseointegrated orthopaedic implants tend to focus on implant stability, surface modifications to enhance integration with host tissue, and reduction in iatrogenic contamination through antibiotic-eluting/bacteria-resistant coatings. While these studies are imperative to early success in osseointegration, continued success of percutaneous devices throughout the lifespan of the patient is also critically important. A perpetual challenge to the implant is formation of bacterial biofilm on the abutment. Once adhered, biofilm-based bacteria are recalcitrant and readily contaminate the subcutaneous soft tissue of the stoma. To this end, the rabbit model reported herein replicates the clinical scenario of a patient with a biofilm-contaminated abutment. This model enables preclinical testing of advanced therapeutics beyond the traditional antibiotic-based approach, potentially increasing the longevity of the device.

RevDate: 2025-03-13

Aflakian F, G Hashemitabar (2025)

Biosynthesized silver nanoparticles at subinhibitory concentrations as inhibitors of quorum sensing, pathogenicity, and biofilm formation in Pseudomonas aeruginosa PAO1.

Heliyon, 11(4):e42899.

Pseudomonas aeruginosa infections associated with biofilm are a significant clinical challenge due to the limited efficacy of traditional antibiotics or combination therapies. Hence, exploring novel strategies and assessing different compounds for their anti-biofilm or anti-quorum sensing (QS) properties is imperative. One of the various applications of silver nanoparticles (AgNPs) is to use them as an antimicrobial agent to target bacteria resistant to common antibiotics. This study evaluates the anti-biofilm and anti-virulence effect of biosynthesized AgNPs against P. aeruginosa PAO1 at subinhibitory concentration levels. Minimum inhibitory concentrations (MICs) and biofilm formation capacity were evaluated by the microdilution method and crystal violet method, respectively. Motility assay and virulence factors were investigated in the presence of AgNPs. It was observed that green-synthesized AgNPs at sub-MIC (50 μg/mL) suppressed P. aeruginosa biofilm formation by 78 %. Increased dose-dependent inhibitory effects on virulence phenotypes (LasB elastase, LasA protease, pyocyanin, and motility) regulated by QS were observed. In addition, the relative expression levels of biofilm-related genes including algC, pslA, and pelA were analyzed using RT-qPCR. The expression level of QS-regulated biofilm genes after AgNPs treatment sub-MIC led to a decrease in the expression of algC, pslA, and pelA by 77 %, 83 %, and 68 %, respectively. The findings of this study demonstrated how green AgNPs can effectively inhibit QS at sub-MIC concentrations, indicating their potential as antivirulence agents to deal with challenges related to biofilm formation and antimicrobial resistance in P. aeruginosa. This presents a promising alternative to traditional antibiotics in antimicrobial therapy.

RevDate: 2025-03-12
CmpDate: 2025-03-12

Schneider RE, Hamdan JV, KP Rumbaugh (2025)

Biofilm Dispersal and Wound Infection Clearance With Preclinical Debridement Agents.

International wound journal, 22(3):e70145.

Biofilms complicate wound care by causing recurrent infections that are often resistant to debridement and are highly antibiotic-tolerant. We investigated whether the addition of a biofilm dispersal agent could improve the efficacy of debridement. The previous studies have indicated that a glycoside hydrolase cocktail of alpha-amylase and cellulase can act as a potent biofilm dispersal agent. With in vitro and ex vivo Pseudomonas aeruginosa biofilm models, we compared glycoside hydrolases against other, clinically relevant, enzymatic debridement agents (papain, bromelain, and collagenase). Glycoside hydrolase biofilm dispersal was dose-dependent. However, at doses of 1% or above, glycoside hydrolases outperformed, or were comparable, to other enzymatic debridement agents. With our in vivo surgical wound infection model, we evaluated biofilm dispersal using infection dissemination as a proxy. We found that sharp debridement followed by multiple glycoside hydrolase treatments enhanced biofilm dispersal. Furthermore, a single dose of glycoside hydrolase in combination with debridement decreased infection load in acute wounds. Similarly, when we treated established 5-day-old infections, we saw a decrease in infection load and no infection dissemination. Overall, our data suggest that debridement enhances the efficacy of a topical antibiotic ointment, allowing for greater infection clearance.

RevDate: 2025-03-12
CmpDate: 2025-03-12

Balato M, Vitelli M, Petrarca C, et al (2025)

On the effectiveness of electrical characterization of mature Staphylococcal Biofilm.

Scientific reports, 15(1):8445.

In this paper, the authors describe an experimental study carried out on biological samples consisting of a 96-h mature Methicillin-Resistant-Staphylococcus-Aureus biofilm. The initial objective was to electrically characterize the biofilm using impedance spectroscopy, by scanning a wide range of frequencies [1 Hz ÷ 10 MHz]. Concurrently, confocal microscopy observations, XTT assays, crystal violet staining method and colony-forming unit assay were performed to characterize the biological activity. The experimental investigation unexpectedly demonstrated that the reproducibility of measurement data was significantly affected by the destructive interaction between the electric field and the biofilm. This interaction was found to be strongly dependent on both the amplitude of the field and the exposure time. Moreover, a significative reduction of total biomass of the biofilm was found in a specific frequency range [10 kHz ÷ 100 kHz]. The results suggest several limitations of impedance spectroscopy as a tool for biofilm identification, since the "sample under test" must not be altered during the measurement process. Conversely, they demonstrate the deleterious impact of the electric field on the biofilm, thereby unveiling a potentially efficacious therapeutic paradigm for biofilm treatment. We expect that the open issues highlighted in this paper will be a source of inspiration for further understanding of the mechanism of interaction between the electric field and biofilm, both in terms of treatment and diagnosis.

RevDate: 2025-03-12
CmpDate: 2025-03-12

Rindi L, He J, Miculan M, et al (2025)

Legacies of temperature fluctuations promote stability in marine biofilm communities.

Nature communications, 16(1):2442.

The increasing frequency and intensity of extreme climate events are driving significant biodiversity shifts across ecosystems. Yet, the extent to which these climate legacies will shape the response of ecosystems to future perturbations remains poorly understood. Here, we tracked taxon and trait dynamics of rocky intertidal biofilm communities under contrasting regimes of warming (fixed vs. fluctuating) and assessed how they influenced stability dimensions in response to temperature extremes. Fixed warming enhanced the resistance of biofilm by promoting the functional redundancy of stress-tolerance traits. In contrast, fluctuating warming boosted recovery rate through the selection of fast-growing taxa at the expense of functional redundancy. This selection intensified a trade-off between stress tolerance and growth further limiting the ability of biofilm to cope with temperature extremes. Anticipating the challenges posed by future extreme events, our findings offer a forward-looking perspective on the stability of microbial communities in the face of ongoing climatic change.

RevDate: 2025-03-11

Charles-Nino CL, Desai GM, Koroneos N, et al (2025)

Reduced growth and biofilm formation at high temperatures contribute to Cryptococcus deneoformans dermatotropism.

Disease models & mechanisms pii:367293 [Epub ahead of print].

Cryptococcus deneoformans (Cd) and C. neoformans (Cn) differ in geographic prevalence and dermatotropism, with Cd strains more commonly isolated from temperate regions and skin infections. Rising global temperatures prompt concerns regarding selection for environmental fungal species with increased thermotolerance, as high mammalian temperatures provide protection against many fungal species. Cd and Cn strains exhibit variations in thermal susceptibility, with Cd strains being more susceptible to higher temperatures. Here, we identified differences in capsular polysaccharide release, adhesion, and biofilm formation between strains both in vivo and in vitro. Histological results suggest the dermatotropic predilection associated with Cd relates to biofilm formation, possibly facilitating latency and extending fungal survival through protection from high temperatures. We demonstrated that Cn strains were more tolerant to mammalian and febrile temperatures than Cd strains. Similarly, Cd strains showed reduced expression of heat-shock protein 60 and 70, after prolonged exposure to high temperature. Our findings suggest that fungal adhesion, biofilm formation, inflammation, and thermotolerance contribute to tissue tropism and disease manifestation by Cn and Cd, supporting the recently assigned species distinction to each of these serotypes.

RevDate: 2025-03-11

Gross N, Muhvich J, Ching C, et al (2025)

Effects of microplastic concentration, composition, and size on Escherichia coli biofilm-associated antimicrobial resistance.

Applied and environmental microbiology [Epub ahead of print].

UNLABELLED: Microplastics (MPs) have emerged as a significant environmental pollutant with profound implications for public health, particularly as substrates to facilitate bacterial antimicrobial resistance (AMR). Recently, studies have shown that MPs may accommodate biofilm communities, chemical contaminants, and genetic material containing AMR genes. This study investigated the effects of MP concentration, composition, and size on the development of multidrug resistance in Escherichia coli. Specifically, we exposed E. coli to varying concentrations of different MP types, including polyethylene, polystyrene, and polypropylene, across a range of sizes (3-10, 10-50, and 500 µm). Results indicated that the biofilm cells attached to MPs had elevated multidrug resistance (in E. coli. Notably, MPs exhibited a higher propensity for facilitating biofilm and resistance than control substrates such as glass, likely due to their hydrophobicity, greater adsorption capacities, and surface chemistries. Notably, we found that the bacteria passaged with MPs formed stronger biofilms once the MPs were removed, which was associated with changes in motility. Thus, MPs select cells that are better at forming biofilms, which can lead to biofilm-associated AMR and recalcitrant infections in the environment and healthcare setting. Our study highlights the importance of developing effective strategies to address the challenges posed by MPs.

IMPORTANCE: Antimicrobial resistance (AMR) is one of the world's most pressing global health crises. With the pipeline of antibiotics running dry, it is imperative that mitigation strategies understand the mechanisms that drive the genesis of AMR. One emerging dimension of AMR is the environment. This study highlights the relationship between a widespread environmental pollutant, microplastics (MPs), and the rise of drug-resistant bacteria. While it is known that MPs facilitate resistance through several modes (biofilm formation, plastic adsorption rates, etc.), this study fills the knowledge gap on how different types of MPs are contributing to AMR.

RevDate: 2025-03-12

Pandey A, Yadav R, Mishra V, et al (2025)

To Study the Incidence of Biofilm Formation, its Microbiology and its Effect on the Development of Acute and Chronic Rhinosinusitis- A Prospective Study.

Indian journal of otolaryngology and head and neck surgery : official publication of the Association of Otolaryngologists of India, 77(1):34-40.

Bacterial biofilms are organised complex structures having polymicrobial nature in a single community, which provide protection to bacteria from antibiotics by various means. The aim of our study was to determine the prevalence of biofilm-forming bacteria in clinical isolates of acute and chronic rhinosinusitis (ARS and CRS) patients with sinonasal mucopurulence. To know the incidence of bacterial biofilms in patient with ARS and CRS, to study the microbiology of bacterial biofilms in ARS and CRS, to assess the role and effects of biofilm in ARS and CRS and to correlate the association between the formation of the biofilm and development of rhinosinusitis. This prospective study was carried out at a tertiary care centre in Eastern part of India, in which 60 patients were taken as sample size. All patients of rhinosinusitis between age-group of 10 to70 years, who came to our out-patient department, were taken for our study. Biofilm formation was observed in 50% cases and were absent in 50% cases of chronic rhinosinusitis in our study. 83.3% (50) of patients out of 60 patients got improved after treatment and recurrence was observed in only 16.6% (10) of patients. Recurrence was more at 3 months follow-up as compared to follow-up at 1 month, though it was not statistically significant. Though our study highlighted the incidence and role of biofilms in the development of chronic rhinosinusitis, but few more randomized controlled studies involving larger sample sizes should be done to exactly determine the pathophysiological role of biofilms in the development and recurrence of acute and chronic rhinosinusuitis.

RevDate: 2025-03-12

Neetu , Pal S, Subramanian S, et al (2025)

Cellulophaga algicola alginate lyase and Pseudomonas aeruginosa Psl glycoside hydrolase inhibit biofilm formation by Pseudomonas aeruginosa CF2843 on three-dimensional aggregates of lung epithelial cells.

Biofilm, 9:100265.

Pseudomonas aeruginosa is an opportunistic pathogen that produces a biofilm containing the polysaccharides, alginate, Psl, and Pel, and causes chronic lung infection in cystic fibrosis patients. Others and we have previously explored the use of alginate lyases in inhibiting P. aeruginosa biofilm formation on plastic and lung epithelial cell monolayers. We now employ a more physiologically representative model system, i.e., three-dimensional aggregates of A549 lung epithelial cells cultured under conditions of microgravity in a rotary cell culture system to mimic the natural lung environment, and a previously isolated clinical strain, Pseudomonas aeruginosa CF2843 that we engineered by transposon-mediated integration to express Green Fluorescent Protein and for which we also report the complete genome sequence. Immunostaining and lectin binding studies indicated that the three-dimensional cell aggregates harbored sialylated and fucosylated epitopes as well as Muc1, Muc5Ac, and β-catenin on their surfaces, suggestive of mucin secretion and the presence of tight junctions, hallmark features of lung epithelial tissue. Using this validated model system with confocal microscopy and viable bacterial counts as readouts, we demonstrated that Cellulophaga algicola alginate lyase and Pseudomonas aeruginosa Psl glycoside hydrolase, but not Pseudomonas aeruginosa Pel glycoside hydrolase, inhibit biofilm formation by Pseudomonas aeruginosa on three-dimensional lung epithelial cell aggregates.

RevDate: 2025-03-12

Martinet MG, Thomas M, Bojunga J, et al (2025)

The landscape of biofilm models for phage therapy: mimicking biofilms in diabetic foot ulcers using 3D models.

Frontiers in microbiology, 16:1553979.

Diabetic foot ulcers (DFU) affect up to 15-25% of patients suffering from diabetes and are considered a global health concern. These ulcers may result in delayed wound healing and chronic infections, with the potential to lead to amputations. It has been estimated that 85% of diabetes-related amputations are preceded by a diagnosis of DFU. A critical factor in the persistence of this disease is the presence of polymicrobial biofilms, which generally include Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli. The involvement of diabetic comorbidities such as ischemia, hyperglycemia, and immune-compromised status creates a perfect niche for these bacteria to evade the body's immune response and persist as biofilms. Bacteriophage therapy can target and lyse specific bacteria and is emerging as an effective treatment for biofilm-related infections. While this treatment shows promise in addressing chronic wounds, our current models, including animal and static systems, fail to capture the full complexity of DFU. Innovative approaches such as 3D bioengineered skin models, organoid models, and hydrogel-based systems are being developed to simulate DFU microenvironments more accurately in 3D without using ex vivo or animal tissues. These advanced models are critical for evaluating bacteriophage efficacy in biofilm-associated DFU, aiming to enhance preclinical assessments and improve therapeutic outcomes for DFU patients.

RevDate: 2025-03-12

Moreno J, Diana L, Martínez M, et al (2025)

Comprehensive analysis of antimicrobial resistance, biofilm formation and virulence factors of staphylococci isolated from bovine mastitis.

Heliyon, 11(4):e42749.

Bovine mastitis, a prevalent disease, is often attributed to staphylococci species. These microorganisms can express a diverse array of virulence genes and have the capability to form biofilms, establishing a robust defense against antimicrobials and host immune responses. In this study, we analyzed 191 Staphylococcus spp., of which 81 % were identified as Staphylococcus aureus, and 19 % as non-aureus staphylococci (NAS), including species such as S. borealis, S. chromogenes, S. haemolyticus, S. saprophyticus, S. capitis, S. ratti, and S. pasteuri. Our analysis involved determining antimicrobial susceptibility profiles, assessing biofilm-forming capacities, and identifying genes associated with virulence, biofilm formation, adhesion, and antimicrobial resistance. Notably, 17.2 % of the strains exhibited resistance to penicillin, with 97 % carrying the blaZ gene, while 9.4 % demonstrated resistance to erythromycin. All strains were sensitive to gentamicin and cefoxitin. Additionally, resistance was observed for clindamycin (8.4 %) and tetracycline (1.0 %). Concerning biofilm development, 2.6 % displayed no formation, 24.6 % were categorized as weak producers, 47.1 % as moderate, and 25.7 % as strong formers. Our investigation also unveiled the presence of virulence genes, such as superantigens like sea (4.7 %), seb (3.7 %), sec (8.4 %), sed (0.5 %), and tst (6.8 %); Panton-Valentine leukocidin (pvl) (59.7 %); haemolysins hla (88.5 %) and hlb (91.1 %); genes responsible for biofilm production icaA (87.9 %), icaD (78.5 %), and bap (4.2 %); and adhesion genes fnbpA (89.5 %), fnbpB (20.4 %), and clfA (89.0 %). Additionally, the strains were categorized into four groups based on their virulence attributes, revealing differences between S. aureus and NAS, with the latter showing a lower presence of the studied genes compared to S. aureus strains. This research sheds light on the resistance and virulence profiles of staphylococci strains associated with bovine mastitis, providing valuable insights for potential treatment approaches.

RevDate: 2025-03-10

Conquista CM, Braga AS, Francese MM, et al (2025)

Effect of 70 Gy tumor therapeutic radiation applied intermittently or directly on microcosm biofilm composition and dental hard tissues and its potential to cause dental caries.

Journal of dentistry pii:S0300-5712(25)00123-X [Epub ahead of print].

OBJECTIVES: This study compared total (70 Gy, one session) and intermittent (35 sessions of 2 Gy) tumor radiation protocols on tooth morphology (n=5) using Scanning Electron Microscopy-Energy Dispersive X-ray (SEM-EDX) and on microcosm biofilm microbiota (n=12) through colony-forming unit (CFU) counts for Candida spp., total microorganisms, Streptococcus mutans, and total lactobacillus. It also assessed "radiation caries" development via Transverse Microradiography (TMR, n=12).

METHODS: Bovine enamel and root dentin were divided into three groups (n=17): total radiation (1); intermittent radiation (2); and no radiation-control (3). Biofilm was produced using saliva from irradiated (for 1 and 2) or non-irradiated patients (for 3) (n=3 donors) combined with McBain saliva with 0.2% sucrose for 5 days. Data were analyzed using ANOVA/Tukey, t-test, and Kruskal-Wallis/Dunn's tests (p<0.05).

RESULTS: S. mutans and Candida spp. were observed on irradiated dentin compared to control, but these microorganisms were absent in enamel biofilm (S. mutans only in 50% and 12.5% of intermittent and total irradiated enamel). Total microorganisms and lactobacillus numbers were similar between groups, except for total microorganisms in irradiated enamel vs. control (p<0.037). No significant differences in mineral loss or lesion depth were detected between protocols or tissues (p>0.05). SEM-EDX revealed slight differences in magnesium (p=0.0439) and calcium (p=0.0216) content in intermittently irradiated dentin.

CONCLUSIONS: Despite increased cariogenic microorganisms in irradiated biofilm, no greater susceptibility to "radiation caries" was observed under this model.

CLINICAL SIGNIFICANCE: Although the radiotherapy alters oral microbiota and dental tissue morphology, these changes alone do not increase radiation-induced caries risk. Other factors, as salivary changes and diet, need to be better studied.

RevDate: 2025-03-10

Johnston W, R Kean (2025)

Development of a polymicrobial host-bacterial interface biofilm model for bacterial vaginosis.

Anaerobe pii:S1075-9964(25)00015-0 [Epub ahead of print].

Bacterial vaginosis (BV) is characterised by a polymicrobial biofilm forming on the vaginal epithelium. In this study, we have developed a host-pathogen model of BV to replicate disease. We demonstrated tissue colonisation by four key vaginal pathobionts that formed metronidazole tolerant biofilms, with subtle changes in cytotoxicity and inflammation.

RevDate: 2025-03-10

Mujica-Alarcon JF, Gomez-Bolivar J, Barnes J, et al (2025)

The influence of surface materials on microbial biofilm formation in aviation fuel systems.

Biofouling [Epub ahead of print].

The ability of different microbes to form biofilms on materials found in aviation fuel systems was assessed using both individual isolates and complex microbial communities. Biofilm formation by the Gram-negative bacterium, Pseudomonas putida, the fungus Amorphotheca resinae and the yeast, Candida tropicalis, was influenced by material surface properties although this differed between isolates. Biofilm formation was greatest at the fuel-water interface. The Gram-positive bacterium Rhodococcus erythropolis, in contrast, was able to grow on most surfaces. When a subset of materials was exposed to complex microbial communities, the attached microbial community structure was influenced by surface properties and selected for different genera best able to form biofilms on a specific surface. Distinct sub-populations of Pseudomonads were identified, which favoured growth on aluminium or painted surfaces, with a different subpopulation favouring growth on nitrile.

RevDate: 2025-03-10

Roth BJ, Khooblall P, Leelani N, et al (2025)

Antimicrobial resistance and biofilm formation of penile prosthesis isolates: insights from in-vitro analysis.

The journal of sexual medicine pii:8068429 [Epub ahead of print].

BACKGROUND: Inflatable penile prostheses (IPPs) have been shown to harbor biofilms in the presence and absence of infection despite exposure to various antimicrobials. Microbes persisting on IPPs following antibiotic exposure have not been adequately studied to assess biofilm formation capacity and antibiotic resistance.

AIM: In this study, we aimed to assess these properties of microbes obtained from explanted infected and non-infected IPPS using an in vitro model.

METHODS: 35 bacterial isolates were grown and tested against various single-agent or multiple agent antibiotic regimens including: bacitracin, cefaclor, cefazolin, gentamicin, levofloxacin, trimethoprim-sulfamethoxazole, tobramycin, vancomycin, piperacillin/tazobactam, gentamicin + piperacillin/tazobactam, gentamicin + cefazolin, and gentamicin + vancomycin. Zones of inhibition were averaged for each sample site and species. Statistics were analyzed with Holm's corrected, one-sample t-tests against a null hypothesis of 0. Isolates were also allowed to form biofilms in a 96-well polyvinyl plate and absorbance was tested at 570 nm using a microplate reader.

OUTCOMES: Resistance was determined via clinical guidelines or previously established literature, and the mean and standard deviation of biofilm absorbance values were calculated and normalized to the optical density600 of the bacterial inoculum.

RESULTS: Every species tested was able to form robust biofilms with the exception of Staphylococcus warneri. As expected, most bacteria were resistant to common perioperative antimicrobial prophylaxis. Gentamicin dual therapy demonstrated somewhat greater efficacy.

STRENGTHS AND LIMITATIONS: This study examines a broad range of antimicrobials against clinically obtained bacterial isolates. However, not all species and antibiotics tested had standardized breakpoints, requiring the use of surrogate values from the literature. The microbes included in this study and their resistance genes are expectedly biased towards those that survived antibiotic exposure, and thus reflect the types of microbes which might "survive" in vivo exposure following revisional surgery.

CLINICAL TRANSLATION: Despite exposure to antimicrobials, bacteria isolated during penile prosthesis revision for both infected and non-infected cases exhibit biofilm forming capacity and extensive antibiotic resistance patterns in vitro. These microbes merit further investigation to understand when simple colonization vs re-infection might occur.

CONCLUSIONS: Although increasing evidence supports the concept that all IPPs harbor biofilms, even in the absence of infection, a deeper understanding of the characteristics of bacteria that survive revisional surgery is warranted. This study demonstrated extensive biofilm forming capabilities, and resistance patterns among bacteria isolated from both non-infected and infected IPP revision surgeries. Further investigation is warranted to determine why some devices become infected while others remain colonized but non-infected.

RevDate: 2025-03-11

Sarkar A, S Bhattacharjee (2025)

Biofilm-mediated bioremediation of xenobiotics and heavy metals: a comprehensive review of microbial ecology, molecular mechanisms, and emerging biotechnological applications.

3 Biotech, 15(4):78.

Environmental pollution, driven by rapid industrialization and urbanization, has emerged as a critical global challenge in the twenty-first century. This comprehensive review explores the potential of bacterial biofilms in bioremediation, focusing on their ability to degrade and transform a wide array of pollutants, including heavy metals, persistent organic pollutants (POPs), oil spills, pesticides, and emerging contaminants, such as pharmaceuticals and microplastics. The unique structural and functional characteristics of biofilms, including their extracellular polymeric substance (EPS) matrix, enhanced genetic exchange, and metabolic cooperation, contribute to their superior pollutant degradation capabilities compared to planktonic bacteria. Recent advancements in biofilm-mediated bioremediation include the application of genetically engineered microorganisms, nanoparticle-biofilm interactions, and innovative biofilm reactor designs. The CRISPR-Cas9 system has shown promise in enhancing the degradative capabilities of biofilm-forming bacteria while integrating nanoparticles with bacterial biofilms demonstrates significant improvements in pollutant degradation efficiency. As global pollution rises, biofilm-based bioremediation emerges as a cost-effective and environmentally friendly approach to address diverse contaminants. This review signifies the need for further research to optimize these techniques and harness their full potential in addressing pressing environmental challenges.

RevDate: 2025-03-11

Jin HW, YB Eom (2025)

Potent anti-biofilm properties of plumbagin against fluconazole-resistant Candida auris.

Journal of traditional and complementary medicine, 15(2):140-146.

BACKGROUND AND AIM: The escalation of fungal infections is driving an increase in disease and mortality rates. In particular, the emergence of Candida auris (C. auris), which shows powerful resistance to the antifungal drug fluconazole, is becoming a global concern. Furthermore, several biological hurdles need to be overcome by candidate therapeutics because C. auris has the ability to form biofilm. Therefore, this study aimed to investigate the antifungal and anti-biofilm effects of plumbagin, a natural extract, against fluconazole-resistant C. auris (FRCA).

EXPERIMENTAL PROCEDURE: The minimum inhibitory concentrations (MICs) of fluconazole and plumbagin were determined against clinically isolated C. auris. Inhibition of biofilm formation and eradication effects of plumbagin against FRCA were confirmed through minimum biofilm inhibition concentration (MBIC) and minimum biofilm eradication concentration (MBEC) assays. Additionally, the inhibition of metabolic activity in biofilm cells was verified through quantification by XTT reduction assay and visualization by confocal laser scanning microscopy (CLSM). The relative expression levels of the azole resistant gene ERG11, the efflux pump gene CDR1, and the extracellular matrix gene KRE6, were measured.

RESULTS AND CONCLUSION: Plumbagin exhibits antifungal efficacy against C. auris and has been shown to effectively inhibit both the formation and eradication of biofilms produced by FRCA. Furthermore, the metabolic activity inhibition in biofilm cells was both quantified and visually observed. The downregulation of all genes (ERG11, CDR1, and KRE6) by plumbagin was confirmed. Taken together, this study demonstrates that plumbagin has antifungal and anti-biofilm efficacy against FRCA, indicating its potential as an alternative to antifungal agents and a valuable resource in combating FRCA infections.

RevDate: 2025-03-10

Williams D, Rothberg D, Kay W, et al (2025)

In vivo efficacy of a refillable intrawound drug delivery device in a sheep model of biofilm-compromised open fracture-related infection.

Biofilm, 9:100262.

Open fracture-related infection challenges persist in healthcare. From the time open fractures were defined ∼50 years ago, infection rates have gone essentially unchanged. Contributing factors include compromised vasculature, biofilm, and stalled innovations in treatment and prophylaxis. In this study, we engineered and tested the efficacy of a refillable drug delivery device, the Purgo Pouch (Pouch), that sustains local, high dose intrawound antibiotic concentrations in wound sites. We hypothesized that it would manage biofilm-compromised open fracture-related infection better than clinical standards of care. Therapies were tested in a unique sheep model of long bone open fracture-related infection with compromised tissue and biofilm inocula of methicillin-resistant Staphylococcus aureus. Sheep (n = 5/group) were treated with IV vancomycin (10 days), gentamicin-loaded CaSO4 beads (single application), or the Pouch (10 days) loaded with gentamicin alone or a triple antibiotic combination. At 21 days, sheep were euthanized and microbiological and histological data collected. Results indicated that the Pouch managed infection more effectively, reducing bioburden to <10[5] colony forming units (CFU)/sample, which was statistically significant compared to clinical standards, which failed to reduce bioburden to below 10[5] CFU. The hypothesis was supported. The Pouch received Breakthrough Device Designation by the FDA, is being transitioned toward clinical trials, and is a potential solution to the long-standing problem of open fracture-related infection.

RevDate: 2025-03-10
CmpDate: 2025-03-10

Liu XM, Yu Y, Jiang H, et al (2025)

Screening of Anti-Biofilm Compounds From Paeoniae Radix Alba Based on Oral Biofilm Biochromatography.

Biomedical chromatography : BMC, 39(4):e70019.

Oral biofilms, which are known as dental plaque, are the reason for a wide range of oral and systemic diseases, which contribute to serious health risks. Paeoniae Radix Alba (PRA) is traditionally used as a folk medicine with anti-inflammatory, cardioprotective, and hepatoprotective properties. PRA is currently used in a variety of therapeutic approaches for oral diseases. Nevertheless, its inhibitory effect on oral biofilm formation and the basis for its efficacy have not been clarified. This study intended to screen the potential compounds in PRA that inhibit oral biofilm formation using biochromatography. Two biofilm models based on S. mutans were used to determine the inhibitory effect of PRA on biofilm formation. The extraction of PRA was divided into fractions with different polarity, the active fraction screened, and an HPLC profile constructed for the active fraction. Three potential compounds were screened using targeted oral biofilm extraction, and subsequent validation of the efficacy indicated that albiflorin is the main compound in PRA exerting anti-biofilm activity. Our results have revealed the pharmacological substance basis of PRA in inhibiting the formation of oral biofilm and provide a reference for the further use of PRA in the development of oral health products.

RevDate: 2025-03-09
CmpDate: 2025-03-09

Kim S, Jin YH, JH Mah (2025)

Inhibitory effects of garlic, cinnamon, and rosemary on viability, heat resistance, and biofilm formation of Bacillus cereus spores in the broth of a fermented soybean paste stew, Cheonggukjang jjigae.

Food research international (Ottawa, Ont.), 206:116078.

Foods prepared through heating, including broths, have the potential and risk of survival of Bacillus cereus, which has the ability to form spores and biofilms. This study evaluated the efficacy of various natural products (particularly spices) in mitigating B. cereus contamination in Cheonggukjang jjigae (CJ) broth. The following characteristics of B. cereus were examined: viability of vegetative cells (including other pathogenic bacteria) and planktonic spores, heat resistance of planktonic spores and spores in intact biofilms, and biofilm formation and persistence. In an antimicrobial test to evaluate the inhibitory effects of spice and cruciferous vegetable extracts on B. cereus CH3 vegetative cells, cinnamon, garlic, and rosemary extracts were selected as they have shown significant inhibitory effects, with inhibition zones of 20-29 mm in diameter at the highest concentration tested (160 mg/mL, unless otherwise stated). These spice extracts also exhibited antimicrobial activity against other foodborne pathogens, including Staphylococcus aureus, Listeria monocytogenes, Salmonella Typhimurium, and Escherichia coli O157:H7. Garlic extract showed the greatest inhibitory effect on the viability and heat resistance of planktonic spores of B. cereus CH3, and cinnamon and rosemary extracts exhibited similar effects. Garlic extract reduced B. cereus CH3 spore counts in phosphate buffer solution (PBS) and CJ broth by 20.22 % and 14.08 %, respectively, compared to control (treated with the same ethanol amount instead of the extract), and effectively weakened spore heat resistance, reducing the D100°C-values of planktonic spores of B. cereus CH3 in PBS and CJ broth by 32.89 % and 23.08 %, respectively, compared to control. As for the characteristics related to biofilm, garlic extract showed the highest inhibitory effect on biofilm formation and persistence and heat resistance of spores in intact biofilms, followed by rosemary and cinnamon extracts. All three spice extracts completely inhibited biofilm formation even at the lowest concentration (20 mg/mL) at the early stage of biofilm formation. They completely eradicated biofilm persistence formed in brain heart infusion (BHI) and CJ broth at the highest concentration. A high garlic extract concentration (80 mg/mL) also reduced the D100°C-values of spores in biofilms formed in BHI and CJ broth by 16.34 % and 9.00 %, respectively, compared to control. Taken together, garlic extract was most effective in mitigating B. cereus contamination in a concentration-dependent manner in in vitro-menstrua and CJ broth. This study may provide one of the promising strategies to reduce the risk of B. cereus in soybean stews such as CJ.

RevDate: 2025-03-09
CmpDate: 2025-03-09

Yi Y, Chen M, Yang H, et al (2025)

New insights into the role of cellular states, cell-secreted metabolites, and essential nutrients in biofilm formation and menaquinone-7 biosynthesis in Bacillus subtilis natto.

Food research international (Ottawa, Ont.), 206:116052.

Menaquinone-7 (MK-7), known for its health benefits, is in high demand across the health and medical fields. Two-stage fermentation strategy can efficiently enhance MK-7 production by Bacillus subtilis natto (B. subtilis natto). However, B. subtilis natto at different growth phases exhibited significant differences in biofilm formation and MK-7 production during the two-stage fermentation, hindering the efficient and stable synthesis of MK-7. Specifically, 0.72 and 0.25 of biofilm biomass values for cells at the early exponential and stationary phases yield MK-7 concentrations of 55.90 and 12.67 mg/L, respectively, with significant variations in the expression levels of quorum sensing, MK-7 synthesis, and biofilm-related genes detected by RT-qPCR. Subsequently, based on experimental procedures involving fermentation supernatant intervention, nutrient supply, and medium renewal, it was found that the deficiency of essential nutrients, particularly low-molecular-weight (< 1 kDa) fractions of soy protein hydrolysate (SPH), was identified as the primary factor of these differences. Additionally, the influence of cell-secreted metabolites, including the downregulation of surfactin and bacilysin expression by 0.61-fold and 0.33-fold, respectively, further exacerbated these effects. Moreover, the increased proportion of depolarized cells and spores, along with reduced intracellular potassium levels in stationary phase cells, was a secondary effect resulting from the two primary causes. Supplementing with ultrafiltration and 75 % ethanol-precipitated fractions of SPH could restore the MK-7 production by 2.35 and 2.05-fold, and biofilm biomass by 2.43 and 2.11-fold, respectively, in B. subtilis natto at the stationary phase. These findings offer a new perspective on the factors influencing biofilm formation and MK-7 production in B. subtilis natto.

RevDate: 2025-03-09
CmpDate: 2025-03-09

Zhang R, Yang T, Liu Z, et al (2025)

Inducible adhesion and biofilm formation in Salmonella linked to adaptive fatty acid metabolism.

Food research international (Ottawa, Ont.), 206:116006.

Salmonella is one of the leading causes of foodborne illness, worldwide. The biofilm formation of this bacterium may be caused by its persistence in the food environment. However, the trigger factors and adaptive metabolism in Salmonella for biofilm formation are not fully known. Here, we observed the distinct biofilm formation of S. typhimurium 2220 in response to the presence of medium-chain fatty acids and found that the level of biofilm formation was positively linked to the chain length of the medium-chain fatty acids. Through dynamics analysis of biofilm formation, we discovered that decanoic acid (10‑carbon fatty acid, C10) enhanced the initial attachment of strain 2220 on both biotic and abiotic surfaces, while compromising motility. The attachment was not achieved due to the inhibition of flagella expression but driven by enhanced energy metabolism which was shown as intracellular acidification and elevated ATP level. We found the S. typhimurium 2220 strain could adaptively metabolize fatty acid by enhancing the expression of fadL gene. In summary, Salmonella biofilm formation was inducible by adaptive fatty acid metabolism which resulted in the enhanced attachment. Our results uncovered valuable insights into the physiological alteration of this foodborne pathogen, suggesting the potential biofilm trigger in the food environment. These findings could facilitate the development of a new antibiofilm strategy.

RevDate: 2025-03-09

Llorente M, Esteve-Núñez A, R Berenguer (2025)

The introduction of surface oxygen groups on fluid-like electrodes enhances biofilm growth of Geobacter sulfurreducens allowing continuous operation.

Bioelectrochemistry (Amsterdam, Netherlands), 165:108963 pii:S1567-5394(25)00066-0 [Epub ahead of print].

Microbial Electrochemical Fluidized Reactors (ME-FBR) changed the paradigm for growing electroactive bacteria from a biofilm strategy to a planktonic mode, while still performing direct extracellular electron transfer from oxidative metabolism in absence of redox mediators. Glassy carbon was the material selected for growing planktonic Geobacter sulfurreducens in ME-FBR. However, the material was unable to retain cells so applications implying continuous operation have been compromised. In this context, a tailor-made chemical strategy was followed considering the large amount of cytochromes C present on the outermost membrane of bacteria form of the Geobacter genus. In this work, a commercial glassy carbon (GC) was chemically modified with surface oxygen groups (SOGs) mainly carboxylic type with high affinity for heme group of cytochrome C. The functionalized material did conserve the structural and textural features and i) promoted the biofilm formation of Geobacter using acetate as sole carbon and electron donor source, and ii) increased the current density and acetate removal rate in comparison with pristine carbon. Thus, the new material enriched in carboxylic-type SOGs facilitates a-la-carte anchorage of electroactive bacteria to move on from a planktonic-based to a biofilm-based strategy, so ME-FBR operation could be expanded from batch to continuous mode, while electrical current was still possible.

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 )