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Bibliography on: Biofilm

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Robert J. Robbins is a biologist, an educator, a science administrator, a publisher, an information technologist, and an IT leader and manager who specializes in advancing biomedical knowledge and supporting education through the application of information technology. More About:  RJR | OUR TEAM | OUR SERVICES | THIS WEBSITE

RJR: Recommended Bibliography 04 Nov 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®)

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RevDate: 2025-11-03

Xie H, Zhao W, Li J, et al (2025)

Microbial functional characteristics in a full-scale immobilized biochemical tank: focusing on the suspended sludge and carrier-attached biofilm.

Bioprocess and biosystems engineering [Epub ahead of print].

Although microbial immobilization has been widely applied in wastewater treatment, the functional differences between suspended sludge and carrier-attached biofilms remain poorly understood. In this study, we investigated the microbial community structure and potential metabolic differences between suspended sludge (MIS) and polyurethane foam (PUF)-attached biofilms (MIC) in an immobilized biochemical tank (MI) from a chemical fiber plant. Compared to the conventional activated sludge process (CAS), the MI demonstrated significantly enhanced removal efficiencies of 39.4% for COD and 83.3% for BOD. The richness, diversity and unique microorganisms of MIS were higher than those of MIC. The dominant genera in MIS were Aridibacter, Diaphorobacter, Nostocoida, Pirellulaceae, Mucilaginibacter, and Rhodanobacter, while the dominant genera in MIC were Mucilaginibacter, Aridibacter, Nostocoida, Gemmata, Meiothermus, and Mycobacterium. Although the major genera were consistent, their relative abundance varied. Metabolic pathway analysis indicated that MIS showed stronger contributions to the transport of organic pollutants, while their role in nitrogen removal in the wastewater was greater than that of attached microorganisms. In contrast, carbon removal primarily occurred on the MIC. Moreover, the intensity of stochastic processes in shaping bacterial communities was observed as CAS (R[2] = 0.427) > MIS (R[2] = 0.261) > MIC (R[2] = 0.26), suggesting that the carriers enhanced the exposure of microbial communities to deterministic processes. These findings offer concrete theoretical support for the engineering application of microbial immobilization technology in treating industrial wastewater by elucidating key mechanistic insights.

RevDate: 2025-11-03
CmpDate: 2025-11-03

Bahuguna N, Venugopal D, N Rai (2025)

Biotherapeutic Potential of Probiotic Yeast Saccharomyces boulardii Against Candida albicans Biofilm.

Indian journal of microbiology, 65(3):1534-1545.

The potential of innovative and alternative probiotic-based antifungal drugs to treat severe biofilm-associated infections has increased demand in recent years. A potentially fatal systemic fungal disease, candidiasis mostly affects the skin and mucous membranes lining inside body cavities such as the nose, mouth, lips, eyes, ears, and genital area. Candida-induced biofilms are densely arranged communities with specific structures that adhere to the surfaces of embedded devices, are covered by an extracellular matrix, and act as an essential virulent factor. It is crucial to explore innovative approaches to aid in treating such fungal illnesses because conventional medications are no longer effective in treating candidiasis. Researchers have been driven to identify the triggers that cause biofilm to grow and mature due to the difficulties involved with biofilm-related disorders. There are still several challenges in Candidasis disease management in clinical settings. A potentially effective approach involves utilising probiotic microorganisms and/or their metabolites, including probiotic yeast Saccharomyces boulardii. It has a significant role in the prevention or treatment of intestinal disorders. The virulence factors, hyphae production, adhesion, and biofilm development of Candida albicans, a significant human fungal pathogen, are influenced by S. boulardii cells and their metabolite, including capric acid. This article is exploring the biotherapeutic potential of probiotic, particularly S. boulardii against Candidiasis and highlighting the health benefits of probiotics on human health.

RevDate: 2025-11-03
CmpDate: 2025-11-03

Sara R, Mohadeseh K, Mehdi B, et al (2025)

Assessment of the Last-Resort Antibiotics against Extended Spectrum Beta-Lactamase/Carbapenemase and Biofilm Producer Klebsiella Pneumoniae Isolated from Hospitalized Patients in Intensive Care Units (ICUs), Iran.

Archives of Razi Institute, 80(2):451-462.

Pneumonia caused by Klebsiella pneumoniae (K. pneumoniae) is regarded as one of the most prevalent etiologies of nosocomial infections. The objective of this study was to investigate the activity of tigecycline, azithromycin, and colistin against K. pneumoniae isolated from bronchoalveolar lavage (BAL) samples of suspected cases of ventilator-associated pneumonia (VAP) in patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. The present study investigates the activity of tigecycline, azithromycin, and colistin against ESBL/carbapenemase-producing K. pneumoniae. The investigation encompasses the phenotypic and genotypic screening of ESBLs, AmpC beta-lactamases, and carbapenemase enzymes. Furthermore, an evaluation was conducted to ascertain the capacity of the biofilm to form. Consequently, the presence of virulence genes was identified through the implementation of a polymerase chain reaction (PCR) method. The utilization of phenotypic detection tests resulted in the categorization of 27 (29.6%) out of 91 K. pneumoniae isolates as ESBL/carbapenemase-producing K. pneumoniae strains. Furthermore, molecular methods revealed that all 27 K. pneumoniae isolates possessed at least one of the ESBL/carbapenemase-related genes. ESBL-associated genes were detected in 91 K. pneumoniae isolates, including 19.7% blaTEM, 29.6% blaSHV, and 19.7% blaCTX-M. Carbapenemase-related genes were identified in 17.5% of the isolates, including blaOXA-48-like (15.4%) and blaNDM1 (2.1%). The investigation revealed that all 27 of the isolates demonstrated the capacity to form biofilms. In this study, the prevalence of specific genes among ESBL/carbapenemase producer K. pneumoniae isolates was investigated. The genes analyzed included entB, mrkD, fimH, Irp2, wcaG, mrkA, rmpA, iutA, and magA. The results showed that 92.59%, 92.59%, 81.48%, 88.8%, 40.74%, 11.1%, 22.22%, 18.5%, 14.81%, and 33.33% of the isolates carried entB, mrkD, fimH, Irp2, wcaG, mrkA, rmpA, iutA, and magA genes, respectively. However, the iucA gene was not detected in any of the isolates examined. Tigecycline and colistin demonstrated higher efficacy against these isolates. Multilocus sequence typing (MLST) results for four colistin-resistant isolates revealed three distinct sequence types (ST): ST3500, ST273, and two cases of ST2558. The rapid emergence and subsequent dissemination of colistin-resistant and Beta-lactamase-producing K. pneumoniae has led to a worrisome global situation. The effective antimicrobial activity of tigecycline against K. pneumoniae that produce these enzymes may be efficient in hospitalized patients in ICUs with suspected cases of VAP.

RevDate: 2025-11-03
CmpDate: 2025-11-03

Folquitto LRDS, Siqueira FDS, Nunes TR, et al (2025)

Synthesis and Biological Assessment of New Thiazoles for Mycobacterial Infections and Biofilm Disruption.

ACS omega, 10(42):50007-50018.

Sixteen thiazoles, of which nine are unprecedented substances (11, 12, 15, 16, 17, 19, 20, 23, and 24), were obtained by a cyclocondensation reaction between a thioamide and an α-bromoketone, via Hantzsch synthesis. All thiazoles (11-26), along with four thiosemicarbazone derivatives (7-10) and their precursors (1-6), were evaluated for their activity against Mycobacterium species Mycobacterium abscessus, Mycobacterium massiliense, Mycobacterium fortuitum, and Mycobacterium smegmatis, as well as for their antibiofilm properties. Among them, compounds 7, 8, 14, 17, 18, 19, 20, and 21 showed promising results in minimum inhibitory concentration (MIC) assays, demonstrating bactericidal activity within 48 h. Moreover, all these compounds inhibited biofilm formation. Notably, the unprecedented thiazole 17, along with 18 (MIC = 36 μmol L[-1]) and 21 (MIC = 65 μmol L[-1]), exhibited the lowest MIC values against all tested species, outperforming the reference drugs. Furthermore, these compounds showed a high degree of selectivity toward mycobacterial cells, as confirmed by cytotoxicity assays using peripheral blood mononuclear cells (PBMC) and Vero cells. These findings highlight the strong antimycobacterial potential of the new thiazole derivatives, warranting further investigation.

RevDate: 2025-11-03
CmpDate: 2025-11-03

Mistry Y, Mullan SA, Patel M, et al (2025)

Evaluation of In Vitro Biofilm Formation of Leptospira Isolates From Human Samples at Four Different Time Frames.

Cureus, 17(9):e93534.

INTRODUCTION: Biofilm is a group of bacterial cells that are formed through a complex network of intracellular communication, which gives new properties to those organisms, like increased protection and resistance to antimicrobial agents, and decreases the effectiveness of host immune responses. Detection of biofilm and evaluation of biofilm production at different time frames are important parameters for antimicrobial resistance, with no or delayed improvement in patient outcomes even after prolonged antimicrobial therapy.

MATERIAL AND METHOD: This was an experimental research using 33 human Leptospira isolates. Biofilm formation was checked by a quantification method using 96-well polystyrene U-well plates. Biofilm formation was checked on days 5, 7, 14, and 21.

RESULT: The biofilm optical density (OD) remained relatively low and stable on Day 5 (0.0703) and Day 7 (0.0674), with overlapping 95% Cls, suggesting no significant difference between these two time points. However, a marked increase was observed by Day 14, where the OD rose to 0.1189 (95%CI: 0.0986-0.1391), indicating a significant accumulation of biofilm. This upward trend continued through Day 21, with the highest mean OD recorded at 0.1826 (95% CI: 0.1596-0.2055). The widening confidence intervals on Days 14 and 21 reflect increased variability at later stages.

CONCLUSION: Human Leptospira isolates show potential for biofilm production in a time-dependent manner. In the present study, OD of biofilm remains low and stable on days 5 and 7, with a marked increase in OD seen on Day 14 and much on Day 21.

RevDate: 2025-11-03

Jindal S, Bisharat M, Khamaisi B, et al (2025)

Biofilm-Antagonist Ginger-Based 3D-Printable Photoresins for Complex Implant Designs Exhibiting Advanced Multifunctional Biomedical Applications.

Advanced materials (Deerfield Beach, Fla.) [Epub ahead of print].

Since the discovery of 3D-printing, it has revolutionized personalized drug delivery and implants by enabling intricate, customizable designs. However, key challenges remain, including complex design, host immune response, biofilm formation, and infection-induced inflammation at the implant site. This work offers, first-ever, unique ginger-based 3D-printable resins by chemically modifying Zingerol (Zing-OH, a ginger-based component) into photopolymerizable compositions that can print high-resolution complex designs via DLP 3D-printing. Briefly, the Zing-OH is amended via different functional group backbones, resulting in Zing-OH-based resins (ether, ester, and urethane) and their respective prints. Moreover, the Zing-OH prints' thermal, mechanical, and biodegradation properties can be fine-tuned by simply customizing the backbone. Furthermore, the shape memory efficacy and the human bone (nasal cartilage, vestibular, cortical, femur, etc.) mimicking mechanical properties (exhibiting 2-200 MPa compressive strength) makes them more enticing. In tandem, the prints are also hemocompatible as well as cyto-friendly against human skin (HaCaT) and lung (BEAS-2B) cells, and mouse fibroblast (NIH-3T3) cells. Concurrently, an in vivo biocompatibility study in a rat model indicates that the printed materials are biocompatible, showing no signs of severe inflammatory response over a 28-day period. More importantly, the outstanding anti-biofilm and antioxidant efficacies of the Zing-OH prints make them more appealing due to their potential to prevent implant rejection, thus making them promising tools for bone-tissue engineering (BTE) applications.

RevDate: 2025-11-02

Chandramoorthy HC (2025)

Ni-Fe Nanoparticles from Eugenia jambolana Extract Show Enhanced Anti-Biofilm, Anti-Inflammatory, and Antioxidant Effects.

Current pharmaceutical design pii:CPD-EPUB-151500 [Epub ahead of print].

INTRODUCTION: Metallic nanoparticles are of interest for their potent bactericidal and anti-biofilm effects within a favorable therapeutic index. This study reports the green synthesis of bimetallic nickel-iron (Ni-Fe) nanoparticles using Eugenia jambolana extract and evaluates their antimicrobial, anti-biofilm, antiinflammatory, and antioxidant activities.

METHODS: Ni-Fe nanoparticles were synthesized using E. jambolana extract and characterized for crystalline structure, size, stability, zeta potential, and functional groups. Antimicrobial activity was tested against Grampositive (Bacillus subtilis, Staphylococcus aureus), Gram-negative (Escherichia coli, Pseudomonas aeruginosa), and Candida albicans. Anti-biofilm potential was assessed via inhibition and dispersion assays, EPS quantification, and in situ visualization. Anti-inflammatory activity was measured through protein denaturation and nitric oxide scavenging assays, while antioxidant capacity was determined using DPPH and H2O2 scavenging tests.

RESULTS: Crystalline, stable Ni-Fe nanoparticles with favorable functional groups were obtained. At 200 μg/mL, they showed broad-spectrum antimicrobial activity. Biofilm formation was reduced by 50% at 250 μg/mL, and dispersion occurred at 10-50 μg/mL, with S. aureus most susceptible. EPS inhibition at 50 μg/mL was 78% (E. coli), 70% (P. aeruginosa), 73% (B. subtilis), and 91% (S. aureus). Visualization confirmed strong adherence to biofilms. At 250 μg/mL, protein denaturation inhibition reached 45%, nitric oxide scavenging 42.6%, DPPH scavenging 44%, and H2O2 scavenging 49%.

DISCUSSION: Ni-Fe nanoparticles exhibit strong antimicrobial, anti-biofilm, anti-inflammatory, and antioxidant activities, notably against S. aureus. High EPS inhibition and biofilm dispersion suggest potential against biofilm- associated, drug-resistant infections.

CONCLUSION: Green-synthesized Ni-Fe nanoparticles from E. jambolana show multifunctional bioactivities, offering promise for therapeutic applications targeting resistant and biofilm-related infections.

RevDate: 2025-11-02
CmpDate: 2025-11-02

Zhou Y, Zou K, Wang X, et al (2026)

Water quality and biofilm growth in drinking water distribution systems with the low-dose sodium hypochlorite disinfection after ultrafiltration pretreatment.

Journal of environmental sciences (China), 160:647-655.

In this study, the effects of low-dose sodium hypochlorite disinfection on water quality and biofilm growth in drinking water distribution systems (DWDS) after ultrafiltration pretreatment was investigated. The influence of pipeline hydraulic residence time (HRT) on disinfection efficiency, by-product formation, microbial activity, and biofilm growth were considered. The results show that both microbial activities and metabolite secretion were stimulated by increasing HRT, aggravating the potential risk of microbial pollution in DWDS. The enhanced microbial metabolism could further weaken disinfection efficiency by consuming extra residual Chlorine, after which the formation of disinfection by-products was facilitated. Residual Chlorine was found negatively correlated with HRT. With prolonging HRT from 5 to 40 h, the concentration of disinfection by-products (Chlorate, Chlorite, and Trichloromethane) was on a continuously increasing trend by 37 %, 140 %, and 75 %, respectively. But the water kept in pipeline still reliably satisfied the Standards for drinking water quality in China (GB5749-2022). Besides, more biofilm with denser morphologies developed on rubber pipeline gaskets rather than the iron/plastic ones. Rubber material was inappropriate for DWDS due to its potential risk of secondary biological pollution. Prolonging HRT also enhanced the accumulation of dominant bacteria (e.g. Bradyrhizobium and Obscuribacter) and decreased microbial diversity.

RevDate: 2025-11-02

Harsent R, Cattoir V, Pascoe M, et al (2025)

Enterococcus spp. ability to form a dry surface biofilm: a route to persistence on environmental surfaces.

The Journal of hospital infection pii:S0195-6701(25)00293-2 [Epub ahead of print].

BACKGROUND: Healthcare-associated infections (HAIs) present a significant global burden, with resistant pathogens such as vancomycin-resistant enterococci (VRE) being of particular concern. Dry surface biofilms (DSB) have recently emerged as critical reservoirs for multidrug-resistant organisms in healthcare environments, yet little is known about enterococcal DSB formation and persistence.

AIM: This study aimed to evaluate the ability of various Enterococcus species and clinical isolates to form DSB on healthcare-relevant materials, assess their long-term survival, and explore factors influencing DSB culturability.

METHODS: Multiple Enterococcus strains, including epidemic and vancomycin-resistant isolates, were cultured using a standardised DSB formation model on a range of surfaces and materials commonly found in healthcare settings. Culturability was assessed through serial dilutions and colony enumeration. Structural characterisation was performed via scanning electron microscopy (SEM), confocal microscopy and flow cytometry.

FINDINGS: All Enterococcus strains formed DSB on stainless steel and other clinical materials. DSB maintained high culturability (5-6 log10) for up to 84 weeks at 20°C and 55% relative humidity. VRE strains exhibited lower culturability compared to non-VRE. No correlation was found between DSB formation and surface roughness or hydrophobicity. SEM, confocal imaging and flow cytometry confirmed heterogeneity in DSB structure and viability across surfaces.

CONCLUSION: Enterococcus spp. can form persistent, viable DSB on diverse healthcare surfaces, contributing to the environmental persistence of pathogens. The combination of mechanical removal with an effective disinfectant remains at present the best approach for DSB control on hard surfaces. As such, enhanced cleaning and disinfection might be, for the time being, the best approach to control DSB on hard surface.

RevDate: 2025-11-02

Beaugelin I, Bulot S, L Pineau (2025)

Comparison of three methods for biofilm disinfection claim.

The Journal of hospital infection pii:S0195-6701(25)00342-1 [Epub ahead of print].

INTRODUCTION: Biofilms are frequently associated with hospital-acquired infections. To reduce patient risks, disinfectant should be able to inactivate bacteria present within biofilms. Multiple methods are described in literature, but no consensus has been found for disinfection efficacy tests against biofilms.

MATERIALS AND METHODS: Three published Pseudomonas aeruginosa biofilm growing methods were characterized by measuring proteins, TOC (Total organic carbon) and bacterial concentration. The sensitivity of each biofilm to disinfectant was then evaluated according to a test method based on NF EN 14561 against a reference peracetic acid solution (PAA).

RESULTS: Biofilm obtained according to ISO 15883-5 showed higher protein and bacteria contents than biofilms formed using ASTM E2562 or Konrat et al. test methods. The results indicate that ISO 15883-5 biofilm was less sensitive to PAA disinfectant than the two other biofilms and that older biofilm presented a lower sensitivity to the disinfectant.

CONCLUSION: The results of this study show a direct correlation between the duration of growth and the maturity of a biofilm. ISO 15883-5 biofilm grown for 96 hours have greater levels of proteins, TOC and bacteria than the ASTM E2652 and Konrat et al. biofilms grown respectively for 48 hours and 24 hours. The importance of the biofilm maturation phase is confirmed by the disinfection efficacy tests. The results of these tests demonstrate that the biofilms less sensitive to the peracetic acid-based disinfectant are those with the longest maturation phase. Type tests performed on disinfectants to demonstrate that they can be used on medical devices or in healthcare facilities shall include tests against mature biofilms.

RevDate: 2025-11-02

Li R, Wan Y, Zhang X, et al (2025)

Groundwater remediation powered by microbial electron transfer: From electrode-biofilm interactions to field deployment.

Bioresource technology, 441:133566 pii:S0960-8524(25)01533-0 [Epub ahead of print].

Groundwater contamination is a pressing global issue driven by anthropogenic activities and intensified by climate change. Microbial electrochemical technology (MET) has emerged as a promising low-carbon approach that integrates microbial metabolism with electrochemical redox reactions for efficient remediation. However, its field-scale feasibility, long-term stability, and environmental impacts remain insufficiently understood. This review synthesizes recent advances in MET for subsurface pollutant removal and critically examines key barriers to practical deployment. Extracellular electron transfer and pollution conversion mechanisms are discussed, enabling METs to target diverse contaminants. Critical operational factors are analyzed alongside emerging strategies to enhance remediation outcomes. Sustainability, life cycle impacts, and technology readiness are also assessed to evaluate environmental viability. Overall, while challenges like long-term stability and scale-up persist, METs hold significant promise for site-specific pollutant control. This review bridges mechanistic insights with engineering strategies, providing an integrated framework for scalable and sustainable MET applications in groundwater remediation.

RevDate: 2025-11-01

Krsak M, Khaled SA, Reyes Copello JF, et al (2025)

2025 ICM: Minimal Biofilm Eradication Concentration (MBEC) versus Minimum Inhibitory Concentration (MIC).

The Journal of arthroplasty pii:S0883-5403(25)01401-9 [Epub ahead of print].

RevDate: 2025-11-01

Mehmood F, Magsi N, Tariq H, et al (2025)

Unseen Reservoirs: Channel-Associated Biofilm in Reusable Endoscopes and a Low-Cost Reprocessing Framework for Resource-Limited Hospitals.

American journal of infection control pii:S0196-6553(25)00693-5 [Epub ahead of print].

RevDate: 2025-11-01
CmpDate: 2025-11-01

Vishwakarma RK, Yadav BS, Gautam P, et al (2025)

In-vitro analysis of biofilm formation and synergistic antibiotic-phage therapy for amoxicillin-resistant Escherichia coli.

Archives of microbiology, 207(12):336.

Biofilm formation by Escherichia coli (E. coli) significantly enhances bacterial resistance to antibiotics, complicating treatment, particularly in amoxicillin-resistant strains. Bacteriophage therapy demonstrates potential in treating biofilm-related infections, and the combination of phages and antibiotics (phage-antibiotic synergy, PAS) further enhances efficacy. This is the first study to evaluate PAS using penicillin-class antibiotics against multidrug-resistant (MDR) Gram-negative bacteria, E. coli. E. coli-specific lytic bacteriophages were isolated and characterized. PAS was evaluated in both planktonic and biofilm forms using sub-inhibitory concentrations of AMC. The viability of biofilm and planktonic forms was assessed not only by colony counts but also by flow cytometry. Moreover, morphological alterations were evaluated by scanning electron microscopy (SEM), and genomic alterations by PAS were analyzed through whole genome fingerprinting using ERIC PCR. In biofilm and planktonic form, phage first achieved effective bacterial killing after 24 h, when 10[6] PFU/mL was supplemented with amoxicillin clavulanic acid (AMC) combination after 7 h for optimal PAS killing. PAS treatment significantly reduced biofilm viability compared to phage therapy only, while AMC was not effective at all. SEM revealed disrupted cell walls, detachment of flagella, and rupture of bacterial cells, as well as changes in morphology and biofilm matrix in combination therapy. Phage-first treatment with ɸA3 followed by AMC after 7 h effectively eradicates multidrug-resistant E. coli, causing genomic changes that restore antibiotic sensitivity at subinhibitory doses, potentially addressing antimicrobial resistance. In PAS, a cocktail of phages may be advised to avoid the emergence of phage mutant strains.

RevDate: 2025-11-01

Zhuang ZM, Wang Y, Xu FW, et al (2025)

Programmed nanozyme hydrogel enabling spatiotemporal modulation of wound healing achieves skin regeneration after biofilm infection.

Journal of nanobiotechnology, 23(1):694.

RevDate: 2025-11-01
CmpDate: 2025-11-01

Xu J, Wang J, Kang Z, et al (2025)

Mixed-species biofilm with Salmonella in food industry: Persistence, interspecies interaction, and control.

Food research international (Ottawa, Ont.), 221(Pt 2):117348.

Salmonella-induced foodborne diseases pose a considerable threat to human health. In the food industry, Salmonella commonly forms biofilms with other microorganisms. When Salmonella exists within mixed-species biofilms, its tolerance to disinfectants and persistence are enhanced, e.g., increased biomass, difficulties in washing and disinfection processes, survival under the stress of food processing, development of antibiotic resistance, and elevated cytotoxicity to humans. This review systematically evaluates the current knowledge of Salmonella-microbe interactions within mixed-species biofilm models in food-processing environments. Studies have shown that Salmonella persists in food facilities by forming mixed biofilms with resident microbiota. This analysis emphasizes the contributions of biofilm architecture, Salmonella cell-surface appendages, metabolic crosstalk, and molecular signaling pathways in mediating interspecies relationships. Moreover, this review explores novel control strategies for mixed-species biofilms, including enzymatic treatments and antimicrobial delivery systems, to disrupt extracellular polymeric substance barriers, as well as the use of antagonistic microbes and phage therapy to counteract synergistic interactions. By elucidating the mechanisms of Salmonella persistence, interspecies interactions, and mitigation strategies, this review provides critical insights into reducing contamination risks and improving food safety in the food industry.

RevDate: 2025-11-01
CmpDate: 2025-11-01

Afonso AC, Simões M, Saavedra MJ, et al (2025)

Physicochemical, Structural, and Proteomic Insights into Drinking Water-Isolated Acinetobacter calcoaceticus Aggregation and Biofilm Dynamics.

Microbial ecology, 88(1):113.

Acinetobacter calcoaceticus, a ubiquitous Gram-negative bacterium, exhibits remarkable adaptability across diverse environments, including drinking water distribution systems (DWDS), where its biofilm-forming and coaggregation capabilities pose significant public health challenges. This study integrates physicochemical, structural, and proteomic analyses to elucidate the mechanisms underlying A. calcoaceticus aggregation and biofilm dynamics. Surface characterization through contact angle measurements, zeta potential, and co-adhesion energy assessments revealed a predominantly hydrophilic surface with strong electron donor properties and a highly negative charge, promoting intercellular adhesion. Transmission electron microscopy unveiled dense cellular aggregates with extracellular filamentous structures, indicative of enhanced cell-to-cell interactions and potential extracellular polymeric substance involvement. Proteomic profiling identified 2593 differentially expressed proteins between aggregation stages, highlighting metabolic shifts, stress response activation, and upregulation of biofilm-associated proteins, including chaperones and quorum-sensing regulators. Our multidisciplinary approach emphasizes the importance of surface characterization in understanding bacterial community and underscores the critical role of physicochemical properties and proteomic flexibility in A. calcoaceticus biofilm and aggregation ability.

RevDate: 2025-11-01
CmpDate: 2025-11-01

Thakur P, Singh RN, RK Sani (2025)

Long-read methylome analysis of Oleidesulfovibrio alaskensis G20 biofilm under copper stress.

Scientific reports, 15(1):38250.

This study represents the first investigation of 5-methyl cytosine (5mC) DNA methylation patterns in sulfate-reducing bacterial (SRB) biofilms under copper (Cu) stress, utilizing Oxford Nanopore Technologies (ONT) sequencing. DNA methylation is a crucial epigenetic modification that is dynamic and regulates the signals to modulate molecular mechanisms across biological systems. The regulatory roles of DNA methylation in prokaryotic systems remain comparatively understudied than in eukaryotes. Bacteria are highly sensitive to environmental changes and therefore may utilize additional mechanisms like DNA methylation to combat the stresses. Our previous studies, utilizing microscopy and growth analyses, revealed that Oleidesulfovibrio alaskensis G20 (OA G20) biofilms responded to Cu stress. However, the DNA methylation patterns associated with this response remain unexplored, leaving a critical gap in our understanding of the epigenetic mechanisms regulating OA G20 biofilms under Cu stress. This study aims to address this knowledge gap by identifying 5mC DNA methylation in biofilms of OA G20 under Cu stress. To achieve our goal OA G20 biofilms cultivated under 30 µM-Cu ion stress along with control and sequenced through ONT sequencing. DNA methylation analysis was performed using the MicrobeMod pipeline identifying three methylated motifs: TCCG, CCCGCCCG, and CGGGAT in control (0 µM-Cu). TCCG was identified as the predominant methylated motif, with analysis revealing 78,022 genomic positions in the control condition. Of these, 61.7% exhibited 5mC modifications, 33.9% remained unmodified, and 4.4% showed uncharacterized modifications. In contrast, the 30 µM-Cu biofilm showed methylation in only two motifs, TCCG and GCANCTGCGS. Analysis of TCCG revealed 63,315 genomic positions, with 62.7% (39,706 sites) showing methylation and 33.2% (20,990 sites) remaining unmethylated. A total of 1418 common methylated positions were identified for both conditions and there were 341 and 424 genomic positions identified for motif TCCG above 75% methylation in the 0 µM and 30 µM-Cu biofilm samples, respectively. Differential methylation analysis revealed significant variations in methylation patterns across several key genes of crucial molecular pathways, important for biofilm formation, including ATP-Binding Cassettes (ABC) transporters, phosphohydrolase, flagellar biosynthesis, chemotaxis, cobalamin synthase, histidine kinase, and uncharacterized proteins.

RevDate: 2025-10-31

Verma K, Thattaramppilly RM, Mishra A, et al (2025)

Assessing microbial biofilm growth on textile media and its efficiency for wastewater treatment.

The Science of the total environment, 1004:180784 pii:S0048-9697(25)02424-6 [Epub ahead of print].

The growing need for sustainable, cost-effective, and efficient wastewater treatment has spurred interest in the use of unconventional materials like synthetic textile media-based membranes in the Attached Growth Biological Reactor (AGBR). While conventional membranes are effective, their adoption is constrained by high costs, energy demands, and fouling issues. This study evaluates five different textile media: Braided Non-Braided (BNB), Broadly Braided (BB), Spiral Braided (SB), Non-Braided (NB), and Horizontal-Vertical Braided (HVB) for their capacity to support microbial biofilm formation and facilitate treatment of primary-treated municipal wastewater in AGBR systems. Among these, BNB and HVB demonstrated markedly superior biofilm development and were thus selected for further analysis in AGBRs. These systems achieved chemical oxygen demand (COD) removal efficiencies of 62-64 % and attained 85-87 % elimination of ammonia. Kinetic parameters such as maximum microbial growth rates, substrate utilization rates, and yield coefficients were quantified for both autotrophic and heterotrophic communities, providing insight into microbial functional behaviour under varied conditions. Furthermore, textile properties such as linear density and specific surface area were examined, revealing strong correlations with microbial attachment patterns, biofilm density, and reactor performance. These results confirm that textile architecture plays a pivotal role in guiding microbial colonization, mass transfer dynamics, and treatment efficiency. Given their affordability, scalability, and biological compatibility, textile-based media represent a promising alternative to conventional membranes in attached-growth wastewater treatment systems. The techno-economic analysis revealed that, compared to commonly adopted sequencing batch reactors (SBR), AGBR provides a more compact configuration (35 % reduction in footprint) and a cost-effective alternative (35 % lower costs), thereby offering a more sustainable solution for wastewater treatment.

RevDate: 2025-10-31

Liu W, Zhao S, Xie T, et al (2025)

Design, synthesis and biological evaluation of novel coumarin derivatives as Pseudomonas aeruginosa biofilm inhibitors.

European journal of medicinal chemistry, 302(Pt 1):118294 pii:S0223-5234(25)01059-1 [Epub ahead of print].

Biofilm-associated antibiotic resistance in Pseudomonas aeruginosa (P. aeruginosa) poses a critical global health burden. A promising strategy to deal with resistant P. aeruginosa infections is to interfere with biofilm formation and the production of virulence. In this study, we designed and synthesized a series of novel coumarin derivatives by incorporating long alkyl chains from native QS signal molecules into the coumarin scaffold. Compound XDS-23 emerged as the hit compound with an IC50 of 1.26 ± 0.16 μM to inhibit biofilm in P. aeruginosa PAO1. Furthermore, XDS-23 still exhibited significant efficacy in reducing biofilm and virulence in clinically isolated resistant P. aeruginosa. Mechanistic studies revealed that XDS-23 mainly inhibited the las and pqs systems, thereby suppressing biofilm and multiple virulence factors. Notably, XDS-23 demonstrated synergistic activity with polymyxin B, ciprofloxacin, ceftazidime, and tobramycin against P. aeruginosa both in vitro and in vivo, significantly increasing the survival rate of Galleria mellonella when combined with these antibiotics. Collectively, these findings highlight biofilm inhibitor XDS-23 as a promising biofilm inhibitor to combat resistant P. aeruginosa infections.

RevDate: 2025-10-31
CmpDate: 2025-10-31

Nath R, Sarkar P, A Bhattacharjee (2025)

Effect of Nitrosative Stress on Biofilm Formation and Upregulation of 2,3-Butanediol Dehydrogenase in Saccharomyces Cerevisiae.

Current microbiology, 82(12):588.

Nitrosative stress is a phenomenon where reactive nitrogen species (RNS), oxidizes different cellular macromolecules. In this study we investigated the effect of sub-toxic dose of different nitrosative stress agents on S. cerevisiae grown with 2% ethanol as sole carbon source. Our SEM analysis showed significant increase in biofilm production under stress with changes in cellular morphology. Genes responsible for biofilm formation like FLO11, BSC2 and MAC1 in S. cerevisiae upon treatment with ac. NaNO2 and SNP were also found to be upregulated. Redox enzymes like glutathione reductase (GR) showed an increase in specific activity in treated sets but catalase activity had no significant difference. Utilization of ethanol as sole carbon source was followed primarily by assessing the specific activity of Adh2p, which showed a significant 4-fold increase in both treated sets. This was also corroborated with gene expression analysis of ADH2. Together with this estimation of important enzymes of other associated metabolic pathways were also done to understand the changes in metabolic flux. Importantly both glyoxylate cycle and TCA cycle were found to be partially blocked under stress condition whereas, aldehyde reductase (Bdh2p) an important enzyme for 2,3-Butanediol production was found to have upregulated significantly. Altogether our study provides the first report on the effect of nitrosative stress on S. cerevisiae grown on ethanol as a carbon source with possibility to produce 2,3-Butanediol, an industrially important compound, that has a huge demand in the paint, drug and cosmetic industries.

RevDate: 2025-10-31
CmpDate: 2025-10-31

Jin HW, YB Eom (2025)

Biochanin A Suppresses Growth and Biofilm Formation of Fluconazole-Resistant Candida auris.

Current microbiology, 82(12):591.

Invasive fungal infections, especially from Candida auris (C. auris), are a serious threat to immunocompromised patients because of multidrug resistance. Therefore, research into novel antifungal agents or adjuvants for pre-existing treatments is necessary. This study examined the therapeutic potential of biochanin A as an antifungal and anti-biofilm agent against fluconazole-resistant C. auris (FRCA). Its efficacy was determined through minimum inhibitory concentration (MIC), minimum biofilm inhibitory concentration (MBIC), and minimum biofilm eradication concentration (MBEC) assays. The fungal metabolic activity in biofilms was measured using the XTT reduction assay and the results were visualized by confocal laser scanning microscopy (CLSM). We also evaluated the effect of biochanin A on C. auris adhesion and the expression of resistance and virulence-associated genes. Biochanin A inhibited the growth of several C. auris strains, with MIC90 values ranging from 16 to 64 µg/mL, as well as a dose-dependent reduction in MBIC and MBEC. The XTT assay and CLSM confirmed a significant inhibition of metabolic activity and viability. In addition, biochanin A reduced C. auris adherence to epithelial cells and downregulated the expression of the azole resistance gene ERG11 and the extracellular matrix gene KRE6. The results suggest that biochanin A is an effective alternative for managing fluconazole-resistant C. auris infections.

RevDate: 2025-10-31

Laurent JM, Kan A, Steinacher M, et al (2025)

Self-organization of cellulose-producing microbial communities during biofilm spreading.

Soft matter [Epub ahead of print].

Matrix-secreting microorganisms form self-organizing biofilms that provide protection and mechanical robustness to the embedded microbial communities. Biofilms made by cellulose-producing bacteria from Komagataeibacter species are widely used for food and bio-manufacturing, but their self-organization in mixed microbial communities has not yet been reported. Here, we investigate the self-organization and spreading of biofilm communities comprising distinct cellulose-producing variants of K. sucrofermentans. Using fluorescently labeled strains grown on solid culture medium, mixed pairs of variants produced striking spatial patterns, with distinct strains dominating the inner and outer regions of the biofilm. The experiments reveal that pattern formation and the enrichment of one strain in the microbial biofilms are affected by the growth rate, cellulose-production rate, and expansion rate of the constituent bacterial strains. Friction between the cellulose-producing bacteria and the underlying substrate was found to be an important phenotype governing cell segregation in the microbial communities, while cell dominance within the biofilm was linked to the cellulose-producing ability of each strain. Understanding the effect of these traits on the cell composition and structure of microbial communities provides new control parameters to tune the formation of biofilms made by mixed cellulose-producing variants.

RevDate: 2025-10-31
CmpDate: 2025-10-31

Sharma P, Sharma R, Nadkerny V, et al (2025)

Effect of toothbrush type on biofilm and periodontal health in orthodontic patients.

Bioinformation, 21(7):2171-2175.

The sonic brush lowered the growth of biofilm on orthodontic brackets more successfully than both powered and manual toothbrushes did. We show that the subjects in Group C (Sonic tooth brushes) achieved the most substantial progress in plaque index and gingival index scores as well as bleeding on probing results. The biofilm formation on orthodontic brackets was least prominent on metallic brackets as opposed to ceramic or composite resin brackets. People using sonic or powered toothbrushes followed their oral hygiene instructions correctly. Thus, Patients undergoing orthodontic treatment should use sonic toothbrushes for achieving their best periodontal health.

RevDate: 2025-10-30

Ortiz J, Álvarez S, S Aguayo (2025)

Unraveling novel insights into dual-species cariogenic biofilm formation on aged teeth: a comparative analysis on natural vs artificial bioengineered dentin models.

Applied and environmental microbiology [Epub ahead of print].

UNLABELLED: Dental caries is the most prevalent biofilm-associated disease affecting billions of people worldwide, including elderly individuals. Conventional biofilm study methods rely on human or animal-derived samples, posing challenges regarding accessibility, cost, and ethical considerations. While in vitro systems offer a promising alternative, they often fail to replicate the structural characteristics of dentin, which play a crucial role in bacterial adhesion. To bridge this gap, a bioengineered dentin construct has recently been developed as a reproducible and accessible model for studying biofilm formation specifically associated with dental aging. Therefore, this study aimed to assess dual-species Streptococcus mutans and Candida albicans biofilm formation on bioengineered dentin substrates and compare it to biofilm formation on natural human aged dentin. For this, S. mutans UA159 and C. albicans (ATCC 90028) were co-cultured on bioengineered and natural dentin slabs, and polymicrobial biofilm formation and extracellular polysaccharide matrix production were characterized via high-resolution confocal laser scanning microscopy. Following biofilm formation, image processing was conducted using COMSTAT software to determine biofilm growth parameters. Additionally, fluorescence intensity was quantified via microplate readings, and cell viability was assessed using a Live/Dead viability kit. Overall, results showed comparable biofilm formation patterns between the bioengineered and aged dentin, with no significant differences found in biofilm physical properties or viability. These findings suggest that this bioengineered dentin construct provides a reliable platform for studying biofilm formation in the context of dental aging, making it a valuable tool for investigating microbial adhesion and cariogenic biofilm development under controlled conditions, potentially facilitating future research in biofilm-related oral diseases.

IMPORTANCE: Dental caries is one of the most common chronic diseases worldwide and is driven by complex microbial biofilms formed on the tooth's surface. However, existing models for studying these biofilms in the laboratory often rely on human or animal tissues, which are difficult to standardize and present ethical challenges. In this study, we validate a bioengineered dentin-like model that accurately mimics the microarchitecture of aged human dentin, a key site for root caries in the elderly. By comparing biofilms formed by the clinically significant Streptococcus mutans and Candida albicans on both artificial and natural substrates, we show that the engineered model supports biofilm development under comparable parameters and enables detection of changes in microbial virulence. Overall, this platform provides a reproducible and scalable alternative for studying oral biofilms with potential applications in understanding disease pathogenesis, novel treatment testing, and integration into next-generation organ-on-a-chip systems.

RevDate: 2025-10-30

Prabhakaran M, Prabakaran M, Kanagaraja A, et al (2025)

Disruption of quorum sensing and biofilm formation in Pseudomonas aeruginosa by plant-based O-methylated flavonoids.

International microbiology : the official journal of the Spanish Society for Microbiology [Epub ahead of print].

Anti-virulence strategies are gaining recognition as promising alternatives for bacterial infection control. They act by suppressing quorum sensing circuits, disrupting biofilm formation, and inhibiting toxin production. However, the emergence of resistant bacterial mutants highlights the need for anti-virulence agents that do not induce resistance. Pseudomonas aeruginosa produces autoinducers like N-acyl-homoserine lactone (AHL), which enhance cell-population and coordinate gene expression. Plant-derived compounds, particularly O-methylated phenolic flavonoids, have shown promise in overcoming antibiotic resistance. Herein, compounds such as formononetin (isoflavone) and 4'-methoxyflavonol (flavonol) possess pharmacological properties beneficial for human health and have been found to inhibit AHL-mediated virulence factors in P. aeruginosa. These flavonoids effectively reduced the production of virulence factors like exopolysaccharides, elastase, protease, pyocyanin, and rhamnolipids assessed by biochemical assays. Motility assays demonstrated a reduction in bacterial movement, and biofilm formation was quantified and visualized using Zeiss Confocal Laser Scanning Microscopy. Gene expression analysis by RT-qPCR revealed that the flavonoids suppressed las and rhl circuits associated with virulence factor synthesis. Among the selected two compounds, 4'-methoxyflavonol exhibited the strongest inhibitory effect against P. aeruginosa. Overall, this study underscores the dual role of dietary phenolic flavonoids in supporting biological functions and serving as natural anti-quorum sensing agents, offering promising strategies to mitigate bacterial virulence.

RevDate: 2025-10-29

Bhattarai B, GF Christopher (2025)

Using Exogenous Polymers to Engineer Biofilm Viscoelasticity.

ACS applied bio materials [Epub ahead of print].

Biofilms are increasingly found in applications in which their viscoelasticity influences the outcomes. In this study, the use of exogenous charged polymers as a means of engineering biofilm viscoelasticity is explored. Commercially available, neutral, anionic, and cationic polymers are added to the growth medium at concentrations that do not impact the growth rates of Pseudomonas aeruginosa. Biofilms grown from these media in microfluidic channels are then mechanically tested via microrheology and compared to control systems grown without the presence of polymers. Both anionic and cationic polymers result in stiffening of biofilms, whereas neutral polymers have little to no discernible effect, indicating that charge plays an important role in allowing polymers to incorporate into the biofilm matrix. Increasing the molecular weight of the polymer appears to increase the disruption of the biofilm matrix, reducing biofilm stiffness. The mechanism of enhanced stiffness is attributable to the polymer backbone stiffness, providing increased mechanical rigidity to the biofilm matrix after it is incorporated.

RevDate: 2025-10-29

Grenho A, Buterin A, Pallitto PM, et al (2025)

ICM 2025: New Technologies Like Artificial Intelligence, Robotics, and Anti-Biofilm.

The Journal of arthroplasty pii:S0883-5403(25)01049-6 [Epub ahead of print].

RevDate: 2025-10-29

Kumari S, S Das (2025)

Regulatory network of nucleotide second messenger in Pseudomonas aeruginosa PFL-P1 and intercellular signaling molecules for functional amyloid fibrillation in biofilm and stress response.

Research in microbiology pii:S0923-2508(25)00085-3 [Epub ahead of print].

Biofilm formation is governed by quorum sensing (QS) and intracellular signaling, with cyclic di-GMP (c-di-GMP) acting as a key regulator that modulates biofilm stability in response to environmental cues. The present study aims to explore the regulatory network between QS, c-di-GMP signaling, and amyloid production in the marine biofilm-forming bacterium Pseudomonas aeruginosa PFL-P1 under various physicochemical stressors. P. aeruginosa PFL-P1 demonstrated adaptability to diverse conditions typical of marine habitats, attributed to the activity of diguanylate cyclase (dgc86) and phosphodiesterase (pde94) genes regulating c-di-GMP turnover. Gene expression analysis revealed a coordinated regulatory network during biofilm development, with significant upregulation of dgc86, pde94, fapC (functional amyloid synthesis), lasI, rhlI (QS), and nahAc [polycyclic aromatic hydrocarbon (PAH) degradation] at 48 h, indicating a mature biofilm. Under acidic condition (pH 4), all genes except pde94 exhibited an adaptive response (p<0.0001). Salinity ≤1 % enhanced gene expression, whereas salinity ≥5 % suppressed it due to osmotic stress (p<0.0001). At 40 °C, dgc86 (p=0.0457) and fapC (p=0.0444) were upregulated, promoting biofilm stability. Pyrene exposure induced significant upregulation of dgc86, lasI, rhlI, and nahAc (p<0.05), enhancing biofilm formation and PAH degradation while downregulating pde94. Supplementation with C4-HSL and 3OC12-HSL upregulated these genes, reinforcing the role of QS in biofilm regulation. Terrein, a QS and c-di-GMP inhibitor downregulated fapC and nahAc, disrupting biofilm formation and PAH degradation. The strong correlation between c-di-GMP levels, amyloid production, and its high binding affinity to FapC (-11.8 kcal/mol) suggests a dual role for c-di-GMP as a signaling molecule and molecular chaperone in amyloid assembly.

RevDate: 2025-10-29
CmpDate: 2025-10-29

Dghoughi Y, Varin-Simon J, Gangloff SC, et al (2025)

Toward an improved in vitro model of prosthetic joint infection for Staphylococcus aureus biofilm characterization.

Biofilm, 10:100325.

Biofilm formation on orthopedic implants is often implicated in chronic prosthetic and joint infections (PJI) that are complex to manage. To date, no current bacterial in vitro model can fully simulate the PJI environment leading to a lack of knowledge to develop diagnosis tool and adapted treatment. Our project aims to set up an innovative in vitro model to characterize Staphylococcus aureus clinical strains biofilms in a PJI context, focusing on several parameters: culture media, incubation time, atmospheric conditions and support for biofilm growth. Biofilm formation was evaluated in various culture media, by counting both planktonic and adherent bacteria (CFU) and quantifying biofilm biomass using crystal violet staining. A mature biofilm was obtained after 72 h of incubation with a similar proportion of planktonic and adherent bacteria whereas a variable dispersion was observed at 96 h. Comparing two different oxygen concentrations (Hypoxia 2.5 % like in bone site vs Anoxia) revealed that a slight variation had a strong impact on biofilm formation, underlining the fact that the physiological conditions are highly necessary to set a mimetic model. A medium has therefore been developed, the modified Bone-Like Environment (BLE+) allowing a consistent biofilm growth. When studying bacterial adhesion, planktonic bacteria can gather and form aggregates that are distinct from mature biofilms. To avoid this phenomenon, a suspended pegs was used. By holding the pegs in the medium, we specifically drove active bacterial adhesion related to biofilm formation, eliminating interference from sedimented aggregates. Moreover, to limit the interaction between planktonic bacteria and biofilm over the 72 h, a medium renewal was applied at 8 h of incubation with a low impact on biofilm biomass. This method allowed the observation of differences between the USA300 (MRSA) and SH1000 (MSSA) strains: the MSSA showed more adherent bacteria and bigger aggregates than the MRSA strain. In conclusion, the parameters for an in vitro biofilm model simulating PJI context have been validated. These parameters include 2.5 % dioxygen, BLE + supplementation, and 72-h incubation on suspended titanium pegs with a renewal media after a primo bacteria adhesion of 8 h.

RevDate: 2025-10-29

Kendil W, Dergal F, Mediouni RM, et al (2025)

Effect of phosphonium-based ionic liquid against mixed biofilm of Candida albicans and methicillin-resistant Staphylococcus haemolyticus isolated from hemodialysis catheter: assessment using confocal raman mapping and microscopic imaging.

Biofouling [Epub ahead of print].

The emergence of multidrug-resistant pathogens linked to mixed biofilm infections is a significant concern due to limited therapeutic options. This health risk has renewed interest in developing new antibiofilm alternatives. In this study, the antibiofilm potential of a phosphonium-based ionic liquid against a mixed-species biofilm of Candida albicans and methicillin-resistant Staphylococcus haemolyticus (MRSH) was assessed preliminarily using the microbroth dilution assay. The ionic liquid inhibitory profiles were further explored by confocal Raman mapping, scanning electron microscopy (SEM), and fluorescence microscopy (FM). A substantial antibiofilm effect was demonstrated. Raman mapping showed a modified biofilm distribution following ionic liquid treatment, demonstrating the differential inhibitory effects between strains in mixed biofilm. Additionally, FM revealed that the morphological switching of Candida albicans was inhibited, while SEM revealed a disruption of biofilm integrity. On the other hand, the hemolysis test showed the safety profile of the ionic liquid by exhibiting low cytotoxicity at active concentrations.

RevDate: 2025-10-29
CmpDate: 2025-10-29

Seto-Tetsuo F, Ashizawa H, Sasaki Y, et al (2025)

DNase Activity of Prevotella intermedia Impairs Biofilm Development and Neutrophil Extracellular Trap Formation.

MicrobiologyOpen, 14(6):e70102.

Chronic periodotitis is caused by the formation of biofilms. Prevotella intermedia, a gram-negative obligate anaerobic bacterium residing in periodontal pockets is involved in the formation of biofilms and secrets a highly potent DNA-degrading activity. Biofilm contains extracellular DNA as a structural component, suggesting that DNase activity may influence P. intermedia's own biofilm development. Neutrophil extracellular traps (NETs) have mesh-like structures and composed of DNA, histone and antibacterial proteins. NETs play an important role in protecting against infection, but it is possible that DNase of P. intermedia disrupts NETs. The lack of established genetic manipulation has significantly delayed the analysis of DNase pathogenic factors. Recently, we have succeeded in establishing a genetic manipulation technique for P. intermedia. In this study, we created strains lacking two DNase candidate genes, nucA (PIOMA14_I_0621) and nucD (PIOMA14_II_0624), that were highly conserved among P. intermedia strains. We examined biochemical analysis of DNase activity, their effection on biofilm formation, and their evasion of NETs. Here, we showed both of them possessed DNase activities which appeared to account all of DNase activities of the bacterium. The mutant analysis further demonstrated that NucA and NucD destroyed biofilm and NETs formations. Neither one was perfectly responsible for DNase activity, but rather they take turns depending on the conditions. In conclusion, the nucA and nucD genes encode DNases that cooperatively function on biofilm formation and suppress NETs formation in P. intermedia.

RevDate: 2025-10-29
CmpDate: 2025-10-29

Zhang M, Song Q, Liu Z, et al (2025)

Design of Lytic Phage Cocktails Targeting Salmonella: Synergistic Effects Based on In Vitro Lysis, In Vivo Protection, and Biofilm Intervention.

Viruses, 17(10): pii:v17101363.

Salmonella is a major zoonotic pathogen and phage cocktails offer a novel strategy against its infections. This study aimed to characterize Salmonella phages and assess the efficacy of various phage combinations, both in vitro and in vivo. Three phages (PJN012, PJN042, PJN065) were isolated, showing stability across a broad range of temperatures and pH values, and lacking genes associated with lysogenicity, virulence, and antibiotic resistance. Combined with two known phages (PJN025, vB_SalS_JNS02), they formed cocktails tested for lytic activity against S. Enteritidis and S. Typhimurium. Phage cocktails (comprising 2-5 phages) that demonstrated efficacy in vitro were validated using Galleria mellonella models. For S. Enteritidis strain 015, prophylactic cocktail C18 increased larval survival to 90% at 48 h (vs. 3% control). For S. Typhimurium strain 024, phage cocktail 26 showed the best therapeutic effect when co-injected with the bacterium, with a survival rate of up to 85% at 96 h, compared to 30% in the positive control group. Biofilm assays showed cocktails inhibited formation more effectively (e.g., at 24 h, C14 and C17 reduced biofilm formation by 93.74% and 94.21%, respectively) than removed established ones. The cocktails depended on bacterial type, phage genera, combinations, and incubation time. Robust in vitro screening remains crucial for optimizing phage formulations despite potential in vivo discrepancies.

RevDate: 2025-10-29
CmpDate: 2025-10-29

Vidaković Knežević S, Knežević S, Milanov D, et al (2025)

Essential Oils as a Novel Anti-Biofilm Strategy Against Salmonella Enteritidis Isolated from Chicken Meat.

Microorganisms, 13(10): pii:microorganisms13102412.

Salmonella Enteritidis is a serious foodborne threat, being the most reported Salmonella serovar in the past several years. Biofilm formation contributes significantly to its persistence and resistance in food processing environments, making it harder to eliminate using conventional disinfectants. Recently, essential oils have emerged as promising natural alternatives due to their antimicrobial and anti-biofilm properties. In this study, the biofilm-forming ability of Salmonella Enteritidis, isolated from chicken meat, was evaluated under various nutrient conditions and temperatures. Furthermore, the anti-biofilm activity of essential oils derived from oregano, cinnamon, rosemary, clove, and thyme was assessed against strong and moderate biofilms formed by Salmonella Enteritidis. The isolates demonstrated the capacity to form biofilms in tryptic soy broth, meat broth, and Luria-Bertani broth at 37 °C, 15 °C, and 5 °C. All selected essential oils, at their minimum bactericidal concentrations, effectively reduced preformed biofilms by between 36.98% to 74.83%. The destructive effect of essential oils on Salmonella Enteritidis bacterial cells was further confirmed through scanning electron microscopy analysis. In conclusion, the selected essential oils exhibited promising anti-biofilm potential and may serve as effective natural agents for controlling biofilm-associated contamination by Salmonella Enteritidis.

RevDate: 2025-10-29
CmpDate: 2025-10-29

Chi H, Bai J, M Feng (2025)

Electricity Production and Population Dynamics of Microbial Community in a Co-Culture of Iron Mine Soil Biofilm and Shewanella oneidensis MR-1 with Anode as Electron Acceptor.

Microorganisms, 13(10): pii:microorganisms13102383.

Microbial communities that develop within biofilms on electrodes are necessary for the proper functioning of the microbial electrochemical system. However, the mechanism through which an exogenous exoelectrogen influences the population dynamics and electrochemical performance of biofilms remains unclear. In this study, we explored the community structure dynamics and electrochemical characteristics of iron mine soil biofilm co-cultured with Shewanella oneidensis MR-1, with the anode as the electron acceptor, and compared the results with those of iron mine soil biofilms alone on the anode. Shewanella oneidensis MR-1 improved the electrochemical activity of microbial biofilms, resulting in a higher maximum power density of 195 ± 8 mW/m[2] compared with that of iron mine soil (175 ± 7 mW/m[2]) and Shewanella (88 ± 8 mW/m[2]) biofilms individually. The co-cultured biofilms could perform near the highest power density for a longer duration than the iron mine soil biofilms could. High-throughput 16S rRNA gene sequencing of the biofilms on the anode indicated that the relative abundance of Pelobacteraceae in the co-culture system was significantly (p = 0.02) increased, while that of Rhodocyclaceae was significantly (p = 0.008) decreased, compared with that in iron mine soil biofilms. After continuing the experiment for two months, the presence of Shewanella oneidensis MR-1 changed the predominant bacteria of the microbial community in the biofilms, and the relative abundance of Shewanella was significantly (p = 0.02) decreased to a level similar to that in iron mine soil. These results demonstrate that Shewanella oneidensis MR-1 could improve the performance of iron mine soil biofilms in electrochemical systems by altering the composition of the functional microbial communities.

RevDate: 2025-10-29
CmpDate: 2025-10-29

Madduri A, Vanommeslaeghe L, T Coenye (2025)

Is Increased Biofilm Formation Associated with Decreased Antimicrobial Susceptibility? A Systematic Literature Review.

Microorganisms, 13(10): pii:microorganisms13102292.

Biofilm formation is a key factor in microbial survival and persistence, often contributing to reduced antimicrobial susceptibility. This systematic literature review investigates whether increased biofilm formation correlates with decreased antibiotic susceptibility. The literature search was conducted in the Pubmed database and we identified and screened 328 studies, with 35 ultimately meeting the inclusion criteria for detailed analysis. Findings reveal that the relationship between biofilm size and antimicrobial susceptibility is highly variable and influenced by multiple factors, including microbial species, strain-specific traits, antibiotic type, and experimental methodologies. While some studies report a positive correlation between biofilm biomass and reduced susceptibility, others show weak or no such relationships, and statistical support for a correlation is often lacking (also due to small sample sizes). The lack of standardized biofilm quantification methods and susceptibility metrics further complicates cross-study comparisons. These findings underscore the need for standardized protocols and more comprehensive datasets to clarify the complex interplay between biofilm formation and antibiotic susceptibility. Regardless of these difficulties, the available data clearly indicate that 'bigger' biofilms are not by definition less susceptible. Future research should prioritize diverse and sufficiently large strain collections and consistent methodologies to better understand and address biofilm-associated antimicrobial tolerance.

RevDate: 2025-10-29
CmpDate: 2025-10-29

Laaboudi FZ, Amri O, M Rouabhia (2025)

In Vitro Exposure to Vaped Tetrahydrocannabinol Increases Candida albicans (SC5314) Growth, Metabolic Activity, Biofilm Formation, and the Expression of Virulence Genes.

Microorganisms, 13(10): pii:microorganisms13102278.

Vaping tetrahydrocannabinol (THC), a cannabis derivative, using electronic cigarettes (e-cigarettes) could deregulate oral health and lead to oral candidiasis. This study aimed to investigate the effects of vaped THC on Candida albicans growth, metabolic activity, biofilm formation, and the expression of virulence genes. Exposure to e-cigarette aerosol with or without nicotine and with or without 10% or 15% THC increased C. albicans growth and metabolic activity; the effects were more pronounced when THC was present in the e-cigarette aerosol. Biofilm analyses showed that e-cigarette aerosol with THC significantly promoted C. albicans biofilm formation, with the higher THC concentration (15%) having the greater effect. Consistently, e-cigarette aerosol with THC increased the expression of the virulence genes EAP1, SAP2, SAP4, and SAP9. These findings suggested that exposure to vaped THC could contribute to the pathogenesis of oral candidiasis, which may lead to oral health problems.

RevDate: 2025-10-29
CmpDate: 2025-10-29

Liu L, Liu C, Qian R, et al (2025)

The PTS EIIB Component Drives Strain-Specific Virulence in Listeria monocytogenes: Divergent Regulation of Biofilm Formation and Host Infection in High- and Low-Virulence Strains.

Microorganisms, 13(10): pii:microorganisms13102274.

Listeria monocytogenes (L. monocytogenes) is a Gram-positive intracellular pathogen capable of causing severe infections. The Listeria pathogenicity island 4 (LIPI-4) encodes a phosphotransferase system (PTS) with its EIIB component playing a critical role in carbohydrate phosphorylation and virulence. However, the precise function of EIIB in virulence regulation across diverse pathogenic strains remains unclear. Here, we generated an EIIB deletion mutant (LM873ΔEIIB) and its complemented strain (CLM873ΔEIIB) from the low-virulence strain LM873, and performed comparative analyses with the high-virulence strain LM928 and its corresponding mutants. Deletion of EIIB differentially modulated biofilm formation: suppressing it in LM928 while enhancing it in LM873, accompanied by corresponding transcriptional changes in biofilm-associated and virulence genes. Both mutants exhibited impaired hemolytic activity, whereas motility attenuation was specific to LM928ΔEIIB. At the cellular level, LM873ΔEIIB enhanced adhesion to and invasion of Caco-2 but impaired intracellular proliferation in JEG-3; In contrast, LM928ΔEIIB promoted Caco-2 invasion while attenuating JEG-3 adhesion, invasion, and intracellular replication, as well as reducing invasion and proliferation in RAW264.7 macrophage. Animal experiments demonstrated that EIIB deletion attenuated LM928 colonization in the liver and spleen, but had no significant impact on LM873. Collectively, our findings establish EIIB as a strain-dependent virulence regulator in L. monocytogenes, particularly modulating biofilm formation and host-pathogen interactions.

RevDate: 2025-10-29
CmpDate: 2025-10-29

Yang Z, Du X, Hu N, et al (2025)

A Novel Enterococcus Phage Endolysin Lys22 with a Wide Host Range Against Mixed Biofilm of Enterococcus faecalis, Staphylococcus aureus, and Acinetobacter baumannii.

Pathogens (Basel, Switzerland), 14(10): pii:pathogens14101060.

The global surge in multidrug-resistant (MDR) bacterial pathogens has created an urgent imperative for innovative antimicrobial strategies. Enterococcus faecalis, Staphylococcus aureus, and Acinetobacter baumannii demonstrate remarkable antibiotic resistance and dominate hospital-acquired infections. These bacteria often form biofilms, a complex community structure that shields them from immune system phagocytosis, resists antibiotic penetration, and enhances their survival in hostile environments. In clinical cases, these bacteria often form mixed biofilms and lead to treatment failures. Phages and their derivatives have emerged as promising candidates in the fight against drug-resistant bacteria. Lys22, an endolysin derived from an enterococcus phage, has been cloned and demonstrated to possess a broad host range, effectively targeting E. faecalis, various Staphylococcus species, and A. baumannii. When applied to the biofilms formed by these bacteria, Lys22 was found to significantly inhibit both simple and complex biofilms in vitro. Virulent genes, including agrA, sarA, and icaA in S. aureus; asa1, cylA, and gelE in E. faecalis; and OmpA and lpsB in A. baumannii were also downregulated by Lys22. Notably, Lys22 also exhibited a robust protective effect against dual or triple infections involving E. faecalis, S. aureus, and A. baumannii in a zebrafish embryos model, highlighting its potential as a therapeutic agent in combatting multi-bacterial infections.

RevDate: 2025-10-29
CmpDate: 2025-10-29

Moreno-Florez AI, Bedoya-Correa CM, Garcia C, et al (2025)

Antimicrobial Activity of Ethanolic Propolis Extracts from Tame (Arauca) on Oral Biofilm Co-Cultures.

Pathogens (Basel, Switzerland), 14(10): pii:pathogens14100982.

UNLABELLED: Oral diseases such as dental caries, stomatitis, and periodontitis are closely associated with biofilms that are resistant to conventional therapeutic approaches. Streptococcus sanguinis and Streptococcus mutans play a key role as primary and secondary colonizers of oral surfaces, respectively, and interact synergistically with other species, including Candida albicans, to promote the establishment and progression of infection.

OBJECTIVE: To evaluate the antimicrobial activity of ethanolic extracts of propolis from Tame (Arauca) on biofilms formed in co-cultures from reference strains and co-cultures with clinical isolates of oral pathogens.

METHODOLOGY: Propolis was collected from Apis mellifera hives placed in rural Tame (Arauca), located in the foothills of the Eastern Andes (Colombia). Ethanolic extracts of propolis (EEP) were prepared in a 0.07 g/mL concentration and biological characterization was performed on single and complex co-cultures of S. mutans (serotype c), S. sanguinis, and C. albicans using disc diffusion test, determination of MIC and BMC, growth curves and biofilm formation. The cell viability and metabolic activity of primary cell cultures derived from a dental pulp explant were evaluated using the MTT assay.

RESULTS: EEP exhibited higher inhibition zones than chlorhexidine against S. mutans and C. albicans and lower efficacy against S. sanguinis. Among the microorganisms evaluated, S. mutans showed the lowest MIC and BCM values, followed by C. albicans and S. sanguinis. Growth curves and biofilm formation assays revealed higher inhibition in co-cultures of reference strains (S. mutans + C. albicans), while multi-species cultures (S. mutans + S. sanguinis + C. albicans), or clinical strains (S. mutans clinical isolated + S. sanguinis + C. albicans), showed higher resistance. Cell viability assays revealed low cytotoxicity (<30%) in primary cell cultures.

CONCLUSIONS: EEPs exhibited antimicrobial activity against relevant oral pathogens, especially in simple co-cultures, supporting their potential as natural therapeutic alternatives. However, their efficacy decreases in the presence of clinical strains and complex co-cultures, highlighting the importance of considering these variables in the development of oral treatments.

RevDate: 2025-10-29
CmpDate: 2025-10-29

Hamid SJ, Salih TM, TA Aziz (2025)

Rational Design, Computational Analysis and Antibacterial Activities of Synthesized Peptide-Based Molecules Targeting Quorum Sensing-Dependent Biofilm Formation in Pseudomonas aeruginosa.

Pharmaceuticals (Basel, Switzerland), 18(10): pii:ph18101572.

Background/Objective: The rise in bacterial resistance necessitates novel therapeutic strategies beyond conventional antibiotics. Antimicrobial peptides represent promising candidates but face challenges such as instability, enzymatic degradation, and host toxicity. To overcome these limitations, conjugation and structural modifications are being explored. This study focuses on designing peptide-based inhibitors of the quorum-sensing (QS) regulator LasR in Pseudomonas aeruginosa, a key mediator of biofilm formation and antibiotic resistance. Methods: Rationally designed tripeptides and dipeptides conjugated with coumarin-3-carboxylic acid and dihydro-3-amino-2-(3H)-furanone were evaluated using molecular docking. The most promising ligand-protein complexes were further analyzed using molecular dynamics (MD) simulations conducted with the CHARMM-GUI and AMBER tools to assess the stability of the ligand-protein complex systems, and the binding affinities were evaluated using Molecular Mechanics-Poisson Boltzmann Surface Area (MM-PBSA) calculations. Pharmacokinetic and toxicity profiles were predicted using ADMETLab 3.0. Selected compounds were synthesized via solid-phase peptide synthesis, structurally confirmed by [1]H NMR and ESI-MS, and tested for antibacterial and antibiofilm activity against P. aeruginosa ATCC 27853. Results: Computational analyses identified several promising inhibitors with stronger binding affinities than the native autoinducer OdDHL. Coumarin conjugates C004 and C006 showed superior docking scores, while MM-PBSA indicated P004 and C004 had the most favorable binding energies. MD simulations confirmed stable ligand-protein complexes. ADMET predictions highlighted C004 and C006 as having excellent pharmacokinetic properties. Experimental assays showed moderate antibacterial activity (MIC 512-1024 µg/mL) and strong antibiofilm inhibition, particularly for C004 (83% inhibition at ½ MIC). Conclusions: The study demonstrates that peptide-coumarin conjugates, especially C004, are promising tools for disrupting QS and biofilm formation in P. aeruginosa. Further optimization and in vivo validation are needed to advance these compounds toward therapeutic application.

RevDate: 2025-10-29
CmpDate: 2025-10-29

Sakalauskienė GV, A Radzevičienė (2025)

Biofilm and Outer Membrane Vesicle Formation in ESKAPE Gram-Negative Bacteria: A Comprehensive Review.

International journal of molecular sciences, 26(20): pii:ijms26209857.

Antimicrobial resistance (AMR) is a growing global threat, exacerbated by the adaptive mechanisms of Gram-negative ESKAPE pathogens, which include biofilm formation and outer membrane vesicle (OMV) production. Biofilms create robust protective barriers that shield bacterial communities from immune responses and antibiotic treatments, while OMVs contribute to both defense and offense by carrying antibiotic-degrading enzymes and delivering virulence factors to host cells. These mechanisms not only enhance bacterial survival but also increase the virulence and persistence of infections, making them a significant concern in clinical settings. This review explores the molecular processes that drive biofilm and OMV formation, emphasizing their critical roles in the development of AMR. By understanding these mechanisms, new therapeutic strategies can be developed to disrupt these defenses, potentially improving the efficacy of existing antibiotics and slowing the spread of resistance. Additionally, the use of OMVs in vaccine development and drug delivery offers promising avenues for future research. Addressing these challenges requires a comprehensive approach, combining advanced research with innovative therapies to combat the escalating threat of AMR and improve patient outcomes.

RevDate: 2025-10-29
CmpDate: 2025-10-29

Chegini Z, Shariati A, Rajaeih S, et al (2025)

The effectiveness of hydrogel matrix containing nitric oxide, silver nanoparticles, vancomycin, and ciprofloxacin on methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa biofilm isolated from patients with chronic rhinosinusitis.

European journal of medical research, 30(1):1036.

BACKGROUND: Many scientists are studying chronic rhinosinusitis (CRS) due to its high relapse incidence and drug resistance. We investigated the antibiofilm activity and sustained co-release of nitric oxide, silver nanoparticles, vancomycin, and ciprofloxacin in thermosensitive hydrogel (HyNSVC) for bacterial CRS.

METHODS: To identify and isolate Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus (MRSA), samples were taken from 10 patients with CRS who underwent Functional Endoscopic Sinus Surgery (FESS), and then they were diagnosed using culture and molecular methods. The HyNSVC was synthesized, and its physicochemical characteristics were evaluated using different methods. The broth microdilution assay and the MTP (microtiter plate) method assessed the minimum inhibitory concentration (MIC) and antibiofilm effects. The inhibitory impact of HyNSVC on the expression of biofilm-associated genes was evaluated using real-time PCR. The cytotoxic effect of HyNSVC on the human epithelial cell line A549 was assessed.

RESULTS: The results of the SEM showed that the hydrogels have a porous structure and that the pores are interconnected. The molecular weights and polydispersity index (PDI) of the copolymer determined using gel permeation chromatography (GPC) were 5759 Daltons, 6270 Daltons, and 1.089, respectively. The anticipated molecular weight determined by H-NMR spectroscopy was around 5947 Daltons. Also, the porosity of the hydrogels was in the range of 80-90%. The HyNSVC MIC was 250 µg/ml for both bacteria. The 2 × MIC of HyNSVC reduced mature biofilm by 62% in P. aeruginosa and 68.1% in MRSA. The presence of HyNSVC did not significantly reduce gene expression. Finally, the MTT experiment showed no toxicity against A549 cells at the MIC concentration.

CONCLUSION: Our findings illustrated the efficacy of employing HyNSVC for drug release regulation and antibiofilm activity for bacterial infection, suggesting a promising treatment for CRS.

RevDate: 2025-10-29
CmpDate: 2025-10-29

Yan C, Zhang J, Yang Y, et al (2025)

Virulence factors, biofilm formation and antifungal resistance in Candida albicans from recurrent vulvovaginal candidiasis patients: a comparative study.

Scientific reports, 15(1):37557.

Recurrent vulvovaginal candidiasis (RVVC) is a common, refractory fungal infection affectingwomen, primarily caused by Candida albicans. The interplay among fungal virulence factors, biofilm formation, and antifungal resistance is crucial in the pathogenesis of RVVC. This study compared 50 Candida albicans isolates from RVVC patients and 50 from asymptomatic vaginal colonizers. Antifungal susceptibility testing was performed using the broth microdilution method. Biofilm formation was assessed via crystal violet staining, and the expression levels of virulence factor hydrolases (SAP, PL, Lip) and cell wall protein genes (ALS1, ALS3, HWP1) were analyzed using phenotypic assays and quantitative real-time PCR (qRT-PCR). Pearson correlation analysis was used to evaluate the relationships among these parameters and antifungal resistance. RVVC isolates exhibited significantly higher MICs for fluconazole, voriconazole, and itraconazole. Biofilm formation ability and the expression levels of SAP, PL, Lip, ALS1, ALS3, and HWP1 were also significantly higher in RVVC isolates. A moderate correlation was observed between antifungal drug MIC values and biofilm OD, while a weak correlation existed between MIC values and ALS/HWP1 gene expression. Notably, hydrolase expression showed no significant correlation with resistance. Candida albicans from RVVC patients demonstrated enhanced biofilm formation, virulence factor expression, and antifungal resistance. Biofilm-mediated drug tolerance may be a key mechanism underlying the refractoriness of RVVC. Targeting biofilm formation and virulence factor genes may offer novel strategies for managing RVVC.

RevDate: 2025-10-29
CmpDate: 2025-10-29

Ebrahimi FA, Siasi E, Yazdian F, et al (2025)

Nanotechnology Meets superbugs: biocompatible polymeric nanoparticles combat MDR Klebsiella pneumoniae via gene suppression and biofilm Inhibition.

Scientific reports, 15(1):37708.

Carbapenem-resistant Klebsiella pneumoniae (CRKP) is a critical threat in healthcare settings due to its limited treatment options and high resistance to conventional antibiotics. This study explores the potential of polycaprolactone (PCL) nanospheres as a delivery vehicle for imipenem to combat multidrug-resistant CRKP. Imipenem-loaded nanospheres, with an average size of 610 ± 125 nm and an encapsulation efficiency of 84.5%, were synthesized using a double-emulsion method and characterized for morphology, size, drug loading, and release profile. The formulation demonstrated a substantial improvement in antibacterial activity, with an eightfold reduction in minimum inhibitory concentration compared to free imipenem. The nanoparticles also significantly inhibited biofilm formation and accelerated bacterial killing. Molecular analysis showed marked suppression of key resistance genes. Additionally, cytotoxicity assays confirmed high biocompatibility, with over 80% viability in fibroblast cells. These findings indicate that PCL-based nanocarriers enhance the efficacy and safety profile of imipenem, offering a promising strategy for addressing antibiotic resistance in CRKP.

RevDate: 2025-10-29
CmpDate: 2025-10-29

Savorana G, Redaelli T, Truzzolillo D, et al (2025)

Stress-hardening behaviour of biofilm streamers.

Nature communications, 16(1):9497.

Bacteria's ability to withstand mechanical challenges is enhanced in their biofilm lifestyle, where they are encased in a viscoelastic polymer matrix. Under fluid flow, biofilms can form as streamers - slender filaments tethered to solid surfaces and suspended in the flowing fluid. Streamers thrive in environments subjected to intense hydrodynamic stresses, such as medical devices and water filters, often resulting in catastrophic clogging. Their colonisation success may depend on a highly adaptable mechanical response to varying stress conditions, though the evidence and underlying mechanisms of this adaptation remain elusive. Here, we demonstrate that biofilm streamers exhibit a stress-hardening behaviour, with both differential elastic modulus and effective viscosity increasing linearly with external stress. This stress-hardening is consistent across biofilms with different matrix compositions, formed by various bacterial species, and under diverse growth conditions. We further demonstrate that this mechanical response originates from the properties of extracellular DNA (eDNA) molecules, which constitute the structural backbone of the streamers. In addition, our results identify extracellular RNA (eRNA) as a modulator of the matrix network, contributing to both the structure and rheological properties of the eDNA backbone. Our findings reveal an instantaneous, purely physical mechanism enabling streamers to adapt to hydrodynamic stresses. Given the ubiquity of extracellular nucleic acids (eNA) in biofilms, this discovery prompts a re-evaluation of their functional role in biofilm mechanics, with potential implications for biofilm structural integrity, ecological resilience, and colonisation dynamics.

RevDate: 2025-10-28

Ouyang S, Zhao HP, CY Lai (2025)

Propane-driven efficient BPA degradation in groundwater: Transformation pathways, microbial ecology and enzymatic mechanisms in a membrane biofilm reactor.

Journal of hazardous materials, 499:140214 pii:S0304-3894(25)03133-4 [Epub ahead of print].

The widespread occurrence of bisphenol A (BPA) in groundwater has raised growing concern due to its endocrine-disrupting effects. This study demonstrates for the first time that a propane-fed membrane biofilm reactor (C3H8-MBfR) achieved efficient BPA degradation, with rates up to 1157.8 ± 42.7 μg·L[-1]·d[-1]. In-situ withdrawal experiments confirmed that propane is essential for maintaining degradation performance. Transformation products (TPs) analysis revealed hydroxylation, oxidative skeletal rearrangement, ipso substitution, and ring-cleavage steps consistent with stepwise detoxification. ECOSAR-based toxicity predictions indicated that BPA degradation potentially leads to a reduced overall ecological risk, although minor toxic TPs might still pose residual risks. Multi-omic profiling identified a metabolically diverse microbial consortium dominated by J033 sp., Methyloversatilis discipulorum (M. discipulorum), Macondimonas, and Gemmobacter sp., which expressed key oxidative enzymes including cytochrome P450 (CYP450), particulate methane monooxygenase (pMMO), and propane monooxygenase (PrMO). Enzymatic inhibition assays supported their crucial roles in BPA transformation. The generated intermediates were subsequently transformed by these upstream oxidizers together with downstream degraders, such as M. discipulorum. These findings reveal a previously unrecognized, enzyme-driven network for BPA degradation in the C3H8-fed biofilm, offering a sustainable strategy for mitigating endocrine disrupting compounds from groundwater.

RevDate: 2025-10-28
CmpDate: 2025-10-28

Liu H, Dong Y, Lin Z, et al (2025)

Genomic Insights into an Environmental Vibrio parahaemolyticus Biofilm Isolate: Deciphering Alternative Resistance Mechanisms and Mobilizable Genetic Elements.

Antibiotics (Basel, Switzerland), 14(10): pii:antibiotics14101005.

BACKGROUND/OBJECTIVES: Biofilms are key in spreading antibiotic resistance in various ecosystems. This study employed comparative genomics to examine the resistance and adaptability mechanisms of the Vibrio parahaemolyticus strain Vaw-5, isolated from a seafood market biofilm.

METHODS: A comparative examination of Vaw-5 and 32 publicly available V. parahaemolyticus genomes identified a distinct set of genetic resistance characteristics.

RESULTS: Unlike clinical strains, Vaw-5 lacks acquired antimicrobial resistance genes like the blaCARB and qnr variations. Instead, its resistance potential is based on chromosomal alterations, efflux pump systems (vmeAB, vcmD), and a unique repertoire of 16 strain-specific transposons, including Tn5501 and Tn5393, which are well-known vectors for antibiotic resistance gene (ARG) mobilization. Although not multidrug-resistant, Vaw-5 possesses unique genomic islands that share negligible homology with those of clinical strains, enriched with gene clusters for environmental adaptation, such as exopolysaccharide production and a fully functional Type VI Secretion System. Vaw-5 carries a distinctive plasmid with the resistance gene aac(2')-Ia.

CONCLUSIONS: Biofilm adaptation promotes structural integrity, inherent processes, and resistance above standard ARG acquisition. This study focuses on how biofilm communities in the food chain can operate as covert incubators for mobilizable resistance determinants, emphasizing the significance of ecological monitoring within a One Health paradigm to reduce possible public health hazards.

RevDate: 2025-10-28
CmpDate: 2025-10-28

Ahmad A, Senaidi AS, Almohamadi H, et al (2025)

Electroactive biofilm enhanced microbial electrolysis for sewage sludge-to-energy conversion.

World journal of microbiology & biotechnology, 41(11):414.

In this study, a two-chambered microbial electrolysis cell (MEC) was fabricated using a carbon cloth electrode, a Nafion-117 membrane, and Escherichia coli as the biocatalyst. The system treated sewage sludge with an initial chemical oxygen demand (COD) of 14,843 ± 350 mg/L, reducing it to approximately 170 ± 12 mg/L over the operational period. This configuration facilitated a significant increase in cell volume utilization of 89.5%, and achieved a maximum current production of 18.03 mA, along with hydrogen generation of 24.34 ± 1.3 mL at a biomass concentration of 13.5 ± 1.1 g/L. Cell growth contributed substantially to the degradation of organic matter, with sludge consumption reaching 12 g/L. The system produced an output voltage of 1.88934 ± 0.0091 V within 72 h and achieved the highest power density of 261,037 ± 1,245 mA/m[2]. The improved performance is attributed to the unique configuration of intermembranous live cells, highlighting the potential of biological electrocatalysts in advancing MEC technology. Further experiments demonstrated that when the initial COD load was 2,443 ± 175 mg/L, the MEC achieved a maximum COD removal efficiency of 98.5%. These findings emphasize the importance of optimizing sewage sludge substrate concentration to maximize power generation in MECs while simultaneously reducing the environmental burden of sludge biomass.

RevDate: 2025-10-28
CmpDate: 2025-10-28

Özbek E, Karaca AN, Has EG, et al (2025)

Deciphering the role of SsaE in biofilm regulation and T3SS-dependent virulence of Salmonella Typhimurium.

World journal of microbiology & biotechnology, 41(11):415.

Salmonella enterica serovar Typhimurium is a major causative agent of foodborne diseases around the world, possessing a versatile arsenal of virulence factors that ensure its survival under different environmental conditions and within various host cells. A central element of its intracellular pathogenicity is the Type III Secretion System (T3SS) encoded by Salmonella Pathogenicity Island 2 (SPI-2), where ssa encodes a conserved chaperone-like protein involved in effector protein stabilization. This study aimed to elucidate broader roles of ssaE, particularly in biofilm formation, motility, and epithelial interactions. A deletion mutant (∆ssaE) of S. Typhimurium ATCC 14028 was constructed and complemented using the plasmid pBAD24::ssaE. Growth analysis revealed a delayed entry into the exponential phase, suggesting a role in stress adaptation. This mutant presented dramatically reduced biofilm biomass, cellulose production, and pellicle formation, and altered colony morphology, all of which were partially restored upon complementation. Motility assays at different temperatures indicated the impaired of swimming and swarming. The aggregation assays indicated lower auto-aggregation and co-aggregation with lactic acid bacteria. Adhesion to human epithelial Caco-2 and HEp-2 cells was drastically reduced in the mutant strain as supported by confocal microscopy. Gene expression analysis via qPCR indicated downregulation of virulence and biofilm-associated genes such as ssaB, invA, hilA, csgD, and yaiC. Protein network and docking analyses indicated that SsaE communicates with the regulatory systems controlling both SPI-2 and SPI-1, alongside environmental sensing signaling cascades. These findings reveal that SsaE is a multifunctional regulator bridging secretion system activity with adaptive and virulence-related phenotypes, thereby contributing to the environmental persistence and pathogenic potential of S. Typhimurium.

RevDate: 2025-10-28

Gouveia AG, Taoufiq A, Antunes W, et al (2025)

Metal-induced biofilm formation by radiation resistant bacteria Deinococcus radiodurans and Deinococcus indicus.

Extremophiles : life under extreme conditions, 29(3):38.

RevDate: 2025-10-28

Sun YHR, Ye YF, Shahrour H, et al (2025)

Target based biofilm inhibition and antibiotic enhancement strategy by miR.101.3p using DNA tetrahedrons.

Journal of innate immunity pii:000549134 [Epub ahead of print].

Cystic Fibrosis is an inherited disease caused by mutations in the CF transmembrane conductance regulator gene. It is characterized by progressive decline in lung function, often driven by chronic respiratory infections, particularly with Staphylococcus aureus and Pseudomonas aeruginosa. MicroRNAs, small, non-coding RNAs that negatively regulate protein expression by binding to mRNA, are altered in people with CF, and contribute to the pulmonary manifestations of CF. The management of CF lung infections is complicated by the formation of bacterial biofilms and antimicrobial resistance. In silico analysis identified hsa.miR.101.3p as a miRNA potentially targeting genes associated with β-lactam resistance and biofilm formation in P. aeruginosa, as well as genes involved in the overall growth of S. aureus. To facilitate delivery, miRNA-mimic DNA oligonucleotides were conjugated to DNA tetrahedrons. The structural integrity of the DNAtd-miRNA complexes was confirmed via transmission electron microscopy, characterized by nanoparticle tracking analysis, and successful bacterial uptake was verified using fluorescence microscopy. DNAtd-miR.101.3p significantly reduced the viability of S. aureus and P. aeruginosa. DNAtd-miR-101-3p enhanced the activity of the beta-lactam antibiotic cefotaxime against planktonic and biofilm-forming P. aeruginosa. The mechanisms involve DNAtd-miR.101.3p targeting of ampC, fleN and pslK. MiR.101.3p, which is expressed in CF bronchial epithelial cells, displays unique inhibition properties against P. aeruginosa and S. aureus in vitro and increases the rate of the bactericidal activity of cefotaxime against P. aeruginosa.

RevDate: 2025-10-27

Yuan W, Zhang S, Guo S, et al (2025)

Distinct methane release patterns associated with two wetlands emergent plants: microbial community in root biofilm and rhizosphere.

Journal of environmental management, 395:127791 pii:S0301-4797(25)03767-3 [Epub ahead of print].

Plant-mediated methane (CH4) transport is a significant emission pathway in wetlands, facilitated by the aerenchyma of emergent plants. This study demonstrates contrasting effects of Sagittaria Sagittifolia (SAG) and Ludwigia leptocarpa (LUD) on system CH4 fluxes under different ambient air temperature. Above 20 °C, SAG exhibited negligible influence on CH4 fluxes but LUD significantly enhanced CH4 fluxes compared to bare sediment, although LUD has a lower aerenchyma proportion than SAG. When temperature was below 20 °C, two plants did not promote CH4 fluxes. The CH4 concentrations peaked in sediment with the highest number of plant root tips in SAG and LUD treatments. Root biofilms exhibited more complex microbial interactions and higher deterministic processes than rhizosphere sediments. Microenvironments shaped by root influenced the distribution of methanogens and methanotrophs in the sediment system, and the methanogenic pathways were mainly hydrogenotrophic in root biofilms, while acetotrophic and hydrogenotrophic methanogenic pathways shared the equivalent existence in rhizosphere sediments. Temperature affected the adundances of the mcrA and pmoA genes, explained the differences in sediment CH4 concentrations and CH4 fluxes, while gene abundance and aerenchyma proportions had a lesser effect than temperature.

RevDate: 2025-10-27
CmpDate: 2025-10-27

Bashir Z, Wani PA, Majeed S, et al (2025)

Biological Peptides, Metabolites and Nanoparticles from Potassium-Solubilizing Bacteria: A Recent Horizon in Antimicrobial and Anti-biofilm Strategies.

Current microbiology, 82(12):579.

This study reports the isolation and comprehensive characterization of two potent potassium-solubilizing bacterial (KSB) strains, KSB-1 and KSB-5, from the rhizospheric soil of Iris kashmiriana locally named as Mazarmond which is cultivated near graveyard. Iris kashmiriana has antimicrobial and anti-inflammatory activities, being also used to treat stomach disorders and respiratory ailments. Both strains exhibited efficient potassium solubilization on mica-amended Aleksandrov medium, with KSB-1 showing the highest solubilization index (3.00 ± 0.12) and a significant pH drop in broth cultures. Morphological, biochemical, and molecular identification revealed KSB-1 as Priestia megaterium and KSB-5 as Bacillus paramycoides. Peptide profiling via sodium dodecyl sulfate - polyacrylamide gel electrophoresis (SDS-PAGE) and ultra-performance liquid chromatography (UPLC) uncovered unique antimicrobial tetrapeptides rich in arginine, histidine, and proline. Two-dimensional correlation spectroscopy - Fourier transform nuclear magnetic resonance (2D COSY-FTNMR) spectroscopy further identified diverse polar and semi-polar metabolites such as amines, ether, alcohol, aldehydes, alkanes, and carboxylic acid contributing to bioactivity. KSB-5 exhibited superior plant growth promoting (PGPR) traits, including phosphate, silicate, and zinc solubilization, siderophore and IAA production, and strong antifungal activity against Fusarium oxysporum. Anti-biofilm assays showed a 57.03% inhibition by KSB-5 extracts. Field emission scanning electron microscopy (FESEM) and energy dispersive X-ray spectroscopy (EDS) analyses revealed hyphal deformation and deposition of biogenic putative nanoparticles-titanium, selenium, and aluminum-on fungal cells, absent in controls. High resolution transmission electron microscopy (HR-TEM) further confirmed intracellular damage including cytoplasmic disintegration and membrane detachment. This is the first report linking KSB strains from Iris kashmiriana with putative nanoparticle-mediated antifungal and anti-biofilm activities, emphasizing their dual role as biofertilizers and biocontrol agents. The findings highlight their potential application in sustainable agriculture and integrated disease management.

RevDate: 2025-10-27

Seike S, Kobayashi H, Takahashi E, et al (2025)

Flagella of Aeromonas veronii biotype sobria promote biofilm formation by biofilm-derived outer membrane vesicles (bOMVs).

Microbiology spectrum [Epub ahead of print].

Aeromonas veronii biotype sobria is a gram-negative rod-shaped bacterium commonly found in various water sources. A. veronii sobria can form biofilms and has been implicated in sporadic infections associated with medical devices like catheters. Previous studies have noted that biofilm-derived outer membrane vesicles (bOMVs) can enhance biofilm formation, though the impact varies across different strains. It remains uncertain whether these variances are attributable to bacterial characteristics or bOMVs components. To investigate this, we analyzed the effects of bOMVs using three typical A. veronii sobria strains (102, 104, and 106) with varying biofilm-forming abilities, noting disparities in biofilm formation by bOMVs derived from each strain. Detailed focus on strain 106, the most responsive to bOMVs, led to the discovery of distinct characteristics, including the presence of flagella-like structures and their role in biofilm formation.IMPORTANCEThis study illuminates the role of A. veronii biotype sobria flagella in promoting biofilm formation by bOMVs through diverse mechanisms. The findings suggest a significant interaction between flagella, outer membrane vesicles, and bacterial cells, influencing the biofilm development process. Understanding these mechanisms could provide crucial insights into the pathogenic potential of A. veronii biotype sobria strains and potentially inform novel strategies for combating biofilm-related infections.

RevDate: 2025-10-27
CmpDate: 2025-10-27

Abdulqadir HN, KI Mahmood (2025)

Exploring the Relationship Between Biofilm Formation and Antibiotic Resistance Genes in Clinically Isolated Klebsiella pneumoniae.

International journal of microbiology, 2025:3833882.

Persistent pathogens pose a significant global health burden, contributing to increased morbidity and mortality rates worldwide. This study investigates the relationship between clinically relevant biofilm-associated and antibiotic resistance genes in Klebsiella pneumoniae isolates. Biofilm-forming capabilities of the isolates were evaluated, and their biomass was quantitatively analyzed. The presence of biofilm-associated and resistance genes (mrkA, blaSHV, blaTEM, and blaKPC) in the samples was identified using conventional PCR. Gene expression levels were quantified via RT-qPCR under acidic and neutral pH conditions, and the results were analyzed statistically to evaluate significance. All clinical isolates were found to be biofilm formers. PCR analysis revealed that a significant proportion of the isolates harbored the mrkA, blaSHV, and blaTEM genes, with prevalence rates of 78%, 89%, and 63%, respectively. In contrast, the blaKPC gene was absent. Statistical analysis revealed a significant (p = 0.0357) association between the presence of the mrkA gene and elevated expression of the blaSHV gene. Strains harboring the mrkA gene demonstrated higher resistance gene expression compared to mrkA-negative strains, particularly under neutral conditions (pH 7). In conclusion, these findings suggest that biofilm may contribute to antibiotic resistance not just by acting as a physical layer but also by modulating the expression of resistance genes. This observed relationship highlights the importance of designing novel therapies that can target both biofilm and resistance mechanisms to combat persistent infections.

RevDate: 2025-10-27
CmpDate: 2025-10-27

Franzino T, Boubakri H, Merlin L, et al (2025)

Carbon source utilization regulates biofilm formation and plant-beneficial interactions of Pseudomonas ogarae F113.

iScience, 28(11):113639.

Root exudate determines the gene expression of root associated bacteria, but the underlying mechanisms are poorly understood. We tested the hypothesis that carbon sources within root exudates regulate interactions of beneficial bacteria with the plant via carbon catabolite repression (CCR). Mutants in CCR genes were constructed in Pseudomonas ogarae F113, and rhizospheric traits were studied. P. ogarae F113 displays reverse CCR. The Δcrc mutant produced more biofilm than the wild-type strain, and its swimming was carbon source dependent. On roots, the bacterial expression of nirS, crcY, and crcZ was higher in the Δcrc mutant. Auxin expression (but not jasmonate signaling) in Arabidopsis thaliana was reduced upon inoculation by Δcrc or ΔcbrB mutants when compared with the wild-type strain. Our findings show that reverse CCR regulates the communication between P. ogarae F113 and A. thaliana, which sheds further light on the significance of root exudates for the functioning of plant-beneficial bacteria on roots.

RevDate: 2025-10-27
CmpDate: 2025-10-27

Peroutka V, Stindlova M, Jencova V, et al (2025)

Assessing the Impact of Polyamide Nanofibrous Material Areal Weight on Lacticaseibacillus rhamnosus Biofilm Formation and Resistance to Storage Conditions and Contamination.

ACS omega, 10(41):47867-47878.

Probiotic biofilms are considered the fourth most advanced generation of probiotics. To maximize the benefits of probiotic biofilms, suitable carriers ensuring bacterial viability during storage are being sought. The use of nanofibrous platforms is beginning to appear as one of the most promising approaches. We investigated the influence of three polyamide (PA) nanofibrous materials with different areal weights (5, 11, 27 g/m[2]) and the resulting morphological properties on the biofilm formation of Lacticaseibacillus rhamnosus ATCC 9595 and its tolerance to various conditions. PA promoted biofilm formation more than the reference material, polystyrene. PA's areal weight influenced the biofilm biomass amount, phenotype, and structure; PAs with a high areal weight promoted biofilm formation. Further, we examined the tolerance of matured biofilms on the PAs to various external conditions: (i) storage temperature (-20, 4, 21 °C), environment (aqueous/dry), and time (0-35 days), (ii) pH (2, 4, 6, 7, 8 and 10), and (iii) bacterial contamination by Staphylococcus aureus and Escherichia coli. Generally, PAs increased biofilm resistance, and the areal weight of the PA played a crucial role in it. The PA with the highest areal weight (27 g/m[2]) provided the highest long-term stability and tolerance of the biofilm and thus was confirmed to be the most suitable tested nanomaterial. The overall results suggest that the presented PAs could be suitable carriers of probiotic biofilm, enabling large-scale production. We also highlight the need for further research on the influence of nanomaterials' morphology on microbial interactions, possibly enabling target modification for a particular use.

RevDate: 2025-10-27
CmpDate: 2025-10-27

Medadurai K, Kennedy SM, Balasubramani J, et al (2025)

Microstructural and functional analysis of PLA-based biofilm reinforced with Sechium edule.

Food chemistry: X, 31:103130.

This paper details the development and characterization of biodegradable composite biofilms composed of polylactic acid (PLA) reinforced with Sechium edule peel powder, a sustainable agricultural by-product. The biofilms were produced using solvent casting with different filler loadings (0-20 wt%) and assessed for mechanical, morphological, thermal, and environmental characteristics. The results demonstrated a notable increase in tensile strength (up to 38.5 MPa at 10 % SE) and modulus, as well as enhanced biodegradability and water absorption capacity at elevated reinforcement levels. FTIR validated the successful integration of lignocellulosic functional groups, whilst FESEM and AFM studies demonstrated uniform filler distribution up to 15 %. Biodegradability assessments demonstrated a weight reduction of up to 9.7 % within 7 days under regulated settings, signifying expedited degradation. The incorporation of Sechium edule enhances the functional efficacy of PLA while also advancing circular bioeconomy objectives. These results underscore the composite's promise for sustainable packaging, agricultural mulch films, and low-impact biomedical applications, with significant prospects for industrial scalability.

RevDate: 2025-10-27

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

Insights into epidemiology, molecular characterization and antibiogram profiling of biofilm-forming Staphylococcus aureus isolated from goat mastitis.

The Journal of dairy research pii:S0022029925101192 [Epub ahead of print].

This study was undertaken to investigate the molecular detection of biofilm-producing Staphylococcus aureus (S. aureus) from goat mastitis. An overall 384 milk samples were initially screened for subclinical mastitis (SCM) followed by molecular characterization of S. aureus isolates. The biofilm formation was assessed using Congo Red agar (CRA), a microtiter plate and the presence of the icaA gene. The results revealed a molecular prevalence of 53.24% (115/216) for pathogenic S. aureus in milk samples of goats. The phenotypic prevalence of biofilm production by CRA and microtitre methods was recorded to be 38.26% (44/115) and 26.96% (31/115) respectively, while the molecularly confirmed biofilm-forming S. aureus through polymerase chain reaction targeting icaA gene was 58.26% (67/115). The phylogenetic analysis of icaA gene revealed high identity between sequences of study isolates and the isolates of other neighbouring countries. The antibiogram profiling of pathogenic S. aureus showed increased resistance to cefoxitin and oxytetracycline followed by gentamicin. Out of 115, 45.22% (52/115) were declared as multiple drug resistant with multiple antibiotic resistance index greater than 0.2. The study concluded that biofilm-producing S. aureus strains are considered to be a common cause of SCM in dairy goats of Pakistan and biofilm formation is associated with multidrug resistance of study isolates.

RevDate: 2025-10-26
CmpDate: 2025-10-26

Tran T, Duong DV, Le TD, et al (2025)

Metagenomic Characterization of Biofilm and Suspended Microbial Communities in a Hybrid Algal Turf Scrubber-Based Wastewater Treatment System.

APMIS : acta pathologica, microbiologica, et immunologica Scandinavica, 133(10):e70072.

This study investigates a hybrid wastewater treatment system combining a biofilm-based Algal Turf Scrubber (ATS) with a membrane-coupled High Rate Algal Pond (ATS-MHRAP) for shrimp aquaculture effluents. Shotgun metagenomic sequencing was used to compare microbial composition, functional pathways, and antibiotic resistance genes (ARGs) across attached biofilm (ATS1) and suspended biomass (ATS2, HRAP1) under three nutrient loading stages. Biofilm samples (ATS1) exhibited higher microbial richness and evenness, with Shannon index values up to 9.25, compared to 6.93 in suspended cultures. Functional pathways enriched in ATS1 included nitrogen cycling, amino acid metabolism, and terpenoid biosynthesis, with elevated expression of amoA, nirK, and nirS genes under moderate loading. These traits coincided with higher removal efficiency of COD (up to 88.6%), phosphate (82.1%), and total nitrogen (73.4%). ARGs were more diverse in ATS1, with up to 11 resistance classes detected, including β-lactam and sulfonamide genes co-occurring with intI1, indicating possible horizontal gene transfer. The ATS-MHRAP system offers a robust and biologically enriched platform for nature-based aquaculture wastewater treatment. Our findings reveal microbial and functional differentiation between attached and suspended communities, with implications for optimizing dissolved oxygen, nutrient ratios, and retention time.

RevDate: 2025-10-25

Liu W, Yang Y, Lu Z, et al (2025)

Marine nitrifying biofilm pre-coating ultrafiltration membranes coupled with biofloc technology: Enhanced performance of ammonia assimilation and denitrification.

Bioresource technology pii:S0960-8524(25)01513-5 [Epub ahead of print].

The exponential growth of the global population has positioned intensive mariculture as a critical solution for food security and economic stability. Three widely adopted intensive mariculture systems, biofloc technology (BFT), flow-through systems (FTS), and recirculating aquaculture systems (RAS), continuously face challenges related to nitrogen/phosphorus accumulation and biosecurity risks. Although integrating BFT with ultrafiltration (UF) has been shown to enhance nitrogen removal in marine RAS, direct carbon source supplementation during the start-up stage significantly suppressed the efficiency of the marine nitrification system, thereby intensifying ammonia and nitrite toxicity. This study developed a BFT-marine nitrifying biofilm pre-coating UF combined process (BFT-NUF process) that maintained ammonia and nitrite concentrations below 0.21 mg/L throughout the start-up stage. The total nitrogen in the recirculating water was < 1 mg/L during the long-term operation (days 26-250), with 100 % and 99.1 % removal efficiencies for Vibrio cholerae and Vibrio parahaemolyticus, respectively. The tryptophan-like and fulvic acid-like substances from polyhydroxyalkanoate catabolism promoted both ammonia assimilation and denitrification. The polysaccharide-dominated biofouling layers reduced irreversible membrane fouling. Stable microbial networks with Rhodobacteraceae as keystone species in NUF system enable fast start-up of BFT-NUF process and eliminated risks of dissimilatory nitrate reduction to ammonium (DNRA). Partial least-squares path modeling confirmed that keystone taxa closely related to C/N ratio significantly enhanced nutrient removal through ammonia assimilation (λ = 0.65, p < 0.05) governed by glnA and gltB/D genes. This study establishes a theoretical foundation for the application of the BFT-NUF process in sustainable marine RAS.

RevDate: 2025-10-25

Tan T, Xu Z, Tao L, et al (2025)

Siderophore-mediated iron enrichment in the biofilm matrix enhances plant iron nutrition.

Cell reports, 44(11):116481 pii:S2211-1247(25)01252-5 [Epub ahead of print].

Plant-beneficial microorganisms are frequently reported to enhance iron (Fe) nutrition in plants, yet the precise underlying mechanisms remain largely unknown. Although both bacterial siderophore production and biofilm formation are beneficial for microbial plant growth promotion, these two bacterial traits have been studied separately. Here, we reveal a strong coupling between these two bacterial traits in enhancing plant Fe uptake using the biofilm-forming rhizobacterium Bacillus velezensis SQR9. We demonstrate that SQR9 biofilms accumulate Fe on plant roots and serve as an Fe reservoir. Crucially, the siderophore bacillibactin enables biofilm Fe accumulation from the environment, while simultaneously stimulating Fe acquisition mechanisms in plants. Field experiments confirmed the ability of SQR9 to boost crop yields in alkaline soils, highlighting its potential for improving iron-limiting plant performance. Our findings emphasize a key role of rhizobacterial siderophores and biofilms in Fe uptake and offer mechanistic insights for microbial biofortification strategies against Fe deficiency in crops.

RevDate: 2025-10-24

Nasrollahian S, Halaji M, Mostaghimi T, et al (2025)

Phylogenetic Diversity, Biofilm Production, and Antibiotic Resistance Profiling of Uropathogenic Escherichia coli Isolated from Children with Vesicoureteral Reflux: Complicating Factors for Treatment and Recurrent Urinary Tract Infections.

Microbial drug resistance (Larchmont, N.Y.) [Epub ahead of print].

Introduction: Uropathogenic Escherichia coli (UPEC) are the most common cause of urinary tract infections (UTI). This study investigated the genetic relatedness, biofilm-forming capacity, and antimicrobial resistance profiles in the extended-spectrum beta-lactamase (ESBL)-producing UPEC collected from children with vesicoureteral reflux (VUR) suffering from UTI. Materials and Methods: In this cross-sectional investigation, a total of 80 nonduplicated UPEC isolates were collected from children afflicted with VUR. Antimicrobial susceptibility testing and phenotypic production of ESBL were conducted according to the Clinical and Laboratory Standards Institute (2023) recommendations. Furthermore, PCR tests were used to detect the presence of ESBL genes. Biofilm formation in 96-well microtiter plates was assessed. Finally, the clonal diversity of the isolates was examined using the Enterobacterial Repetitive Intergenic Consensus (ERIC)-PCR. Results: Out of all collected isolates, 71.2% (n = 57/80) were ESBL producers and 31.2% (n = 25/80) were multidrug resistant (MDR). The frequency of the blaCTX-M gene was 65.0% and 77.5% of the isolates were biofilm producers. ESBL-producing UPEC isolates were clustered by the ERIC-PCR method into the nine groups labeled A-I. Conclusion: Our findings indicate a high and rising prevalence of MDR and ESBL-producing UPEC among children with VUR. This underscores the urgent need for appropriate empirical antibiotic selection, routine monitoring of resistance patterns, and long-term prophylactic strategies to reduce recurrence and improve clinical management in this vulnerable population.

RevDate: 2025-10-24
CmpDate: 2025-10-24

Jung SJ, Ashrafudoulla M, Bai J, et al (2026)

Receptor-specific phage resistance induced phenotypic and gene expression shifts in Salmonella Typhimurium impacting biofilm formation on food contact surfaces.

Food microbiology, 134:104937.

Bacteriophages are gaining increasing attention as targeted biological control agents against multidrug-resistant (MDR) foodborne pathogens. However, repeated exposure to bacteriophages can induce the emergence of bacteriophage-resistant mutant (BIM) strains, which may exhibit altered physiological characteristics that impair therapeutic efficacy. This study investigated the phenotypic and molecular adaptive mechanisms of multidrug-resistant Salmonella Typhimurium BIMs that acquired resistance to receptor-specific bacteriophages (STP-1 and STP-2) targeting O-antigen and flagella. Two representative BIM strains-MO-4 (O-antigen mutant) and MF-6 (flagella mutant)-were analyzed using phenotypic microarray, motility and biofilm experiments, confocal microscopy, and qRT-PCR. MO-4 exhibited extensive metabolic changes, including 10 alterations in carbon source utilization and increased resistance to 11 antibiotics, while MF-6 showed changes in sensitivity to osmotic and pH stress and increased susceptibility to 5 antibiotics. Both BIM strains exhibited reduced motility but maintained similar or enhanced biofilm formation ability on food contact surfaces. Confocal microscopy analysis revealed structurally distinct biofilms with reduced thickness and increased density. qRT-PCR analysis showed receptor-specific transcriptional changes: MO-4 lost rfaL expression, supporting O-antigen deficiency, while MF-6 showed increased fljB expression and decreased fliK expression, indicating changes in flagellar regulation. Both BIMs showed differences in the expression of tolC, rpoS, and luxS, suggesting changes in efflux, stress response, and quorum sensing. These results highlight receptor-dependent adaptation of phage-resistant Salmonella variants and emphasise the need to evaluate both genetic and phenotypic outcomes when designing effective phage-based control strategies for food safety.

RevDate: 2025-10-24
CmpDate: 2025-10-24

Wang A, Gu Y, Cheng Y, et al (2026)

Inhibitory effect of gentisic acid on biofilm formation of Listeria monocytogenes in vitro and on food-related surfaces.

Food microbiology, 134:104920.

In this study, the inhibitory effects of gentisic acid on biofilm formation and virulence gene expression in Listeria monocytogenes were systematically evaluated. Based on growth curve analysis, sub-inhibitory concentrations (SICs) chosen for gentisic acid were 0.0625, 0.125 and 0.25 mg/mL. Gentisic acid at SICs significantly inhibited biofilm formation by L. monocytogenes in a dose-dependent manner, as confirmed by scanning electron microscopy (SEM). Additionally, gentisic acid significantly reduced bacterial adhesion to and invasion of Caco-2 cells, with adhesion rate decreased by 31.43 %-70.87 %, and invasion rate decreased by 18.58 %-50.72 %. Moreover, gentisic acid impaired bacterial motility and aggregation, reduced the swimming diameter by 52.41 %-92.89 % and the swarming diameter by 34.69 %-87.76 %. It also suppressed the secretion of extracellular polymeric substances. Furthermore, RT-qPCR analysis showed that all six genes related to biofilm formation and virulence were regulated following treatment with gentisic acid. Meanwhile, gentisic acid also inhibited the formation of biofilm by 25.89 %-45.93 %. Moreover, gentisic acid significantly inhibited biofilm formation by L. monocytogenes on food and its contact surfaces. Collectively, these findings suggest that gentisic acid is a promising anti-biofilm agent that offers new strategies for the prevention and control of L. monocytogenes biofilm formation in food systems.

RevDate: 2025-10-24
CmpDate: 2025-10-24

Pant K, Palmer J, S Flint (2026)

Conditional synergy: Impact of nutrient abundance on multispecies biofilm formation and sanitizer tolerance.

Food microbiology, 134:104952.

Bacteria exist in varying nutrient conditions and complex microbial consortia. Pseudomonas fluorescens, Staphylococcus aureus, and Listeria monocytogenes are commonly occurring biofilm-formers, share a similar nutritional niche, and have been isolated from common surfaces in multispecies environments. Biofilm properties, including biomass (O.D590 nm), cell concentration (log CFU/cm[2]), exopolysaccharide content (μg/cm[2]), structure, and sanitizer tolerance (sodium hypochlorite), were observed under varying nutrient (full-strength TSB and 10 % TSB) conditions on polystyrene surfaces for single and multispecies biofilm. The synergistic interactions between the bacteria in multispecies biofilm were found to be nutrient-dependent, with significantly higher (p < 0.05) biofilm formation, exopolysaccharide content, and sanitizer tolerance in high nutrient conditions (TSB) compared with low nutrient conditions (10 % TSB). The cell concentrations in the biofilm (single and multispecies) were found to be comparable between TSB and 10 % TSB. All three bacteria involved showed increased tolerance against sanitizers in the multispecies arrangement compared to their single-species counterparts, with significantly higher survival for L. monocytogenes (5.3 log CFU/cm[2]) in a multispecies biofilm compared to its single-species counterpart (2.3 log CFU/cm[2]). A positive correlation was observed between exopolysaccharide concentration and sanitizer tolerance. This study highlights the importance of taking multiple bacteria and their growth environment into account when understanding sanitizer response, as it varies in multispecies biofilm setups and according to nutrient availability.

RevDate: 2025-10-24

Nugrahani AW, Hertiani T, Haniastuti T, et al (2025)

Anacardic acid as a promising natural antimicrobial agent: Mechanisms of action, biofilm inhibition, and advances in nano-encapsulation for enhanced therapeutic efficacy.

Fitoterapia pii:S0367-326X(25)00577-5 [Epub ahead of print].

Anacardic acid (AA), a phenolic lipid primarily found in Anacardium occidentale and related plants, exhibits promising antimicrobial activity, notably against biofilm-associated infections. AA disrupts bacterial membranes, inhibits vital metabolic pathways, and interferes with quorum sensing, making it effective against both planktonic and biofilm-forming bacteria such as Staphylococcus aureus, Streptococcus mutans, and methicillin-resistant S. aureus (MRSA). Its distinctive chemical structure, particularly the length and degree of unsaturation of its alkyl side chains, plays a critical role in antimicrobial potency. Higher unsaturation enhances membrane disruption and antibacterial effects, while structural modifications, including branching and derivatisation, improve bioavailability and efficacy. Despite its potent action, AA has limited solubility and stability; thus, advances in nano-encapsulation techniques and complexation with carriers like hydroxypropyl-β-cyclodextrin have improved its clinical potential. AA and its analogues not only disrupt biofilm architecture but also suppress bacterial metabolism and inhibit extracellular polymeric substance (EPS) production, key factors in biofilm resilience. AA-based coatings and formulations offer promising applications in biomedical devices to prevent biofilm formation and combat antimicrobial resistance. AA effectively inhibits biofilm development. Its ability to eradicate mature biofilms is weaker, emphasizing the need for combination therapies or enhanced delivery systems. AA represents a multifunctional, natural antimicrobial candidate with considerable scope for further development to address persistent biofilm-related infections and reduce the global threat of antimicrobial resistance.

RevDate: 2025-10-24

Wang X, Yang C, Li X, et al (2025)

Targeting argH to attenuate Aeromonas dhakensis virulence: A metabolic checkpoint for biofilm formation and stress adaptation.

Veterinary microbiology, 311:110767 pii:S0378-1135(25)00403-1 [Epub ahead of print].

Aeromonas dhakensis is an emerging pathogen linked to systemic infections in diverse animal hosts, with rising prevalence posing a growing threat to animal health. Although the argH gene is traditionally associated with arginine biosynthesis, its role in virulence remains unclear. In this study, a ΔargH mutant of A. dhakensis wild-type C4-1 was constructed to investigate its contribution to pathogenicity. The ΔargH mutant exhibited significantly reduced virulence, as evidenced by reduced biofilm formation, motility, extracellular protease activity, adhesion, and resistance to oxidative stress. Furthermore, the ΔargH mutant exhibited heightened susceptibility to antimicrobial peptides, suggesting a role for argH in stress adaptation. Transcriptomic analysis revealed 518 differentially expressed genes (DEGs), with significant enrichment in pathways associated with membrane structure, flagellar assembly, secretion systems, and biofilm development. These findings indicate that argH acts as a pleiotropic regulator influencing multiple aspects of A. dhakensis virulence.

RevDate: 2025-10-24

Lim H, Abdelahad B, J Holmbäck (2025)

Fatty acid composition of lipids and polyhydroxyalkanoate determination in the air-air biofilm using a two-stage sample extraction and gas chromatography with flame ionization detector.

Journal of chromatography. A, 1764:466465 pii:S0021-9673(25)00809-X [Epub ahead of print].

Modifications in the fatty acyl chain composition of cell lipids significantly influence bacterial biofilm development, and biofilm-forming bacteria synthesise polyhydroxyalkanoates as carbon and energy reserves under challenging environmental conditions. Despite the close relationship between fatty acid composition in lipids and polyhydroxyalkanoates, comprehensive research examining both constituents within biofilms remains limited, and no analytical methodologies support their concurrent analysis. In this study, a two-stage extraction procedure combined with GC-FID analysis was developed to determine both the lipid fatty acid profiles and the polyhydroxyalkanoate content in microbial biofilms. Air-air interfaced bubble biofilms obtained from a mine tunnel environment were analysed to investigate microbial adaptation to low-light and metal-enriched conditions. Nine bubble biofilm samples collected from Ytterby mine, Sweden, demonstrated a consistent fatty acid composition dominated by four main components: mono-unsaturated C16:1 (n-7) and C18:1 (n-7), along with saturated C14:0 and C16:0. Mono-unsaturated and saturated fatty acids accounted for over 90 % of total extracts, while bacterial fatty acids, polyhydroxyalkanoates, and polyunsaturated fatty acids represented approximately 5 %, 2 %, and 1 %, respectively. Two polyhydroxyalkanoate monomers were found in the samples: 3OHC14:0 and 3OHC16:0. The observed fatty acid and polyhydroxyalkanoate profiles closely aligned with those of Nevskia ramosa strains, confirming its predominance within these biofilm communities. The developed analytical methodology enables efficient and cost-effective simultaneous determination of fatty acids of lipids and polyhydroxyalkanoates in microbial biofilms, offering a useful tool for future studies in this field.

RevDate: 2025-10-24

Ahmad Lone R, Chandra Sahoo U, Shakya A, et al (2025)

Biochemical profiling, anti-biofilm, and anti-quorum sensing activities of Psophocarpus tetragonolobus (L.) DC. root-tuber.

Natural product research [Epub ahead of print].

The root-tuber of underutilised Psophocarpus tetragonolobus (L.) DC., was evaluated for its biochemical, elemental, and antimicrobial properties. It revealed a high phenolic (456.58 µg GAE/mg) and flavonoid (586.27 µg QE/mg) content, with quercetin being the most abundant compound. High-performance liquid chromatography (HPLC) profiling reported the presence of catechin, epicatechin, gallic acid, and rutin. Elemental analysis confirmed the presence of beneficial minerals and absence of heavy metals in the root-tuber. Methanolic extracts demonstrated quorum sensing inhibition activity against Chromobacterium violaceum and significant antibiofilm inhibition activity against Pseudomonas aeruginosa PAO1. Molecular docking analyses revealed a strong binding affinity of lectins and thaumatin-like proteins with peroxidase and Glutathione S-Transferase (GST) enzymes, suggesting a mechanistic basis for their antimicrobial action. These findings support the therapeutic and nutraceutical potential of P. tetragonolobus root-tuber.

RevDate: 2025-10-24

Rafique HA, Yu H, Abudukadier A, et al (2025)

Deciphering the Role of pafBC in Mycobacteriophage Resistance and Biofilm Formation.

ACS infectious diseases [Epub ahead of print].

Tuberculosis (TB) remains the world's deadliest bacterial infection, with 8.2 million newly notified cases and an estimated 1.25 million deaths in 2023. Alarmingly, ∼19% of multidrug- or rifampicin-resistant (MDR/RR) strains already meet the World Health Organization (WHO) definition of pre-XDR-TB because they are resistant to at least one fluoroquinolone (FQ). Although gyrA/gyrB target-site mutations dominate clinical FQ resistance, Mycobacteria also rely on transcriptional networks that help them withstand the oxidative and DNA strand-breaking stress caused by these drugs. Central to this response is the heterodimeric transcription factor pafBC, whose WYL domain binds to single-stranded DNA and redirects RNA polymerase to a dedicated promoter set, thereby orchestrating a LexA-independent DNA-damage response (DDR). Up-regulation of pafBC has been linked to enhanced intracellular survival of M. tuberculosis and nontuberculous mycobacteria after FQ exposure, yet the downstream phenotypes and their connection to drug or phage resistance have remained unclear. Here, we demonstrate that deletion of pafBC in Mycobacterium smegmatis profoundly remodels the cell envelope, as evidenced by altered colony rugosity, reduced sliding motility, enhanced aggregation, and a three- to 5-fold decline in quantitative biofilm biomass. Untargeted lipid profiling revealed the selective depletion of long-chain trehalose polyphosphates and other apolar glycolipids that normally decorate the outer membrane─lipid classes that have recently been shown in other studies to serve as essential receptors for therapeutic mycobacteriophages such as BPs and Muddy. Consistent with this lipid deficit, the pafBC mutant exhibited markedly reduced phage adsorption and plaque formation; ectopic expression of RecA restored adsorption efficiency, implicating DDR envelope crosstalk in antiphage defense. Complementation with wild-type pafBC rescued lipid composition, biofilm mass, and phage resistance, whereas a WYL-domain mutant that cannot bind single-stranded DNA failed to do so, underscoring the necessity of canonical pafBC activation for envelope homeostasis. Immunoprofiling in THP-1 macrophages further showed that pafBC-proficient bacilli induce significantly higher secretion of IL-1β, TNF-α, and IL-6 compared to their isogenic mutant. This effect correlated with the presence of intact surface glycolipids, molecules known to interact with scavenger and Toll-like receptors on phagocytes and to enhance opsonizing antibody deposition at the host-pathogen interface. Overall, our findings connect the molecular mechanisms of the pafBC DDR with observable phenotypes such as fluoroquinolone tolerance, biofilm structure, phage resistance, and host immune recognition, by highlighting cell-envelope remodeling as the central factor.

RevDate: 2025-10-24
CmpDate: 2025-10-24

Naz SS, S Zafar (2025)

The role of probiotics in controlling oral biofilm formation and mitigating oral squamous-cell carcinoma risk.

Archives of microbiology, 207(12):332.

This review examines the role of specific probiotic strains in modulating oral biofilms and immune pathways implicated in the prevention of oral squamous cell carcinoma (OSCC). Evidence indicates that Lactobacillus fermentum, L. salivarius, Bifidobacterium animalis, and Streptococcus salivarius effectively disrupt carcinogenic biofilms through multiple mechanisms. These include competitive exclusion, nutrient competition, and the production of antimicrobial peptides and biosurfactants. In addition, they contribute to cancer prevention by detoxifying mutagens such as acetaldehyde and nitrosamines. These probiotics also influence OSCC-relevant immunity by enhancing natural killer cell cytotoxicity, promoting CD8[+] T-cell activity, and inducing TRAIL-mediated apoptosis, while strengthening epithelial defenses via upregulation of tight junction proteins. Multi-strain formulations frequently demonstrate superior efficacy compared to single strains, reflecting potential synergistic mechanisms. Nonetheless, outcomes remain highly strain-dependent and context-specific. Overall, current evidence suggests a promising yet preliminary role for probiotics in OSCC prevention, underscoring the need for rigorously designed, strain-specific clinical trials and optimized delivery systems tailored to the oral environment.

RevDate: 2025-10-24
CmpDate: 2025-10-24

James JJ, Yap CH, Frimayanti N, et al (2025)

Discovery and Structure-Activity Relationship Study of Pyrazolyl Indolenine Derivatives as Staphylococcus aureus Biofilm Inhibitors.

Archiv der Pharmazie, 358(10):e70126.

Staphylococcus aureus-associated infections pose a significant clinical challenge due to biofilm formation, which contributes to antibiotic resistance and persistent infections. The prevalence of methicillin-resistant S. aureus (MRSA) further exacerbates this issue, underscoring the urgent need for effective therapeutic strategies. In this study, we report a potent and selective second-generation MRSA biofilm inhibitor (4ad), which showed a minimum biofilm inhibition concentration (MBIC50) of 0.78 µg/mL and demonstrated ≥ 128-fold selectivity for biofilm inhibition over planktonic growth. Through structural optimisation and fragmentation, we further identified a truncated analogue (5a) that effectively eradicated a preformed MRSA biofilm, with a minimum biofilm eradication concentration (MBEC50) of 0.78 µg/mL-outperforming both the first-generation hit (4e) and the clinically used antibiotics oxacillin and vancomycin. Notably, both 4ad and 5a exhibited no significant impact on planktonic bacterial viability or Vero cell cytotoxicity. Given the broad-spectrum antibiofilm activity of 4e against S. aureus, we investigated its combinatorial effects with antibiotics. 4e demonstrated additive effects in combination with vancomycin, erythromycin, and amoxicillin. Importantly, both structure-activity relationship (SAR) and quantitative structure-activity relationship (QSAR) analyses identified key structural features associated with antibiofilm activity. Collectively, these findings support further development of pyrazolyl indolenine derivatives and mechanistic studies aimed at combating antibiotic-resistant S. aureus biofilm.

RevDate: 2025-10-23

Anonymous (2025)

Leading voices in oral health strengthen consensus on dental plaque biofilm management.

British dental journal, 239(8):525.

RevDate: 2025-10-23

Slade EA, Clayton GE, Hodgkins G, et al (2025)

Direct application of non-thermal plasma technology for the elimination of biofilm from endoscope channels.

Scientific reports, 15(1):37139.

RevDate: 2025-10-23

Pan R, Ding Y, Peng J, et al (2025)

Identification and characterization of a novel bacteriocin PFB252 from Bacillus velezensis with anti-MRSA and anti-biofilm activity for dairy food preservations.

Journal of dairy science pii:S0022-0302(25)00845-8 [Epub ahead of print].

The emergence of methicillin-resistant Staphylococcus aureus (MRSA) and its robust biofilm-forming capability pose severe threats to public health, livestock production, and food safety, and undersocres the urgent need for novel antibacterial and anti-biofilm agents. In this study, we identified and characterized a novel bacteriocin, PFB252, derived from Bacillus velezensis through a multi-step purification process involving acid precipitation, TA-GF75 gel column chromatography, Tiderose Q HP anion-exchange chromatography, and RP-HPLC. PFB252 exhibited remarkable thermal stability, pH tolerance, and resistance to enzymatic degradation, and demonstrated potent antibacterial activity against MRSA. At sub-inhibitory concentrations (1/32 × MIC and 1/16 × MIC), PFB252 significantly disrupted biofilm formation and impaired the metabolic viability of embedded bacteria, while drastically reduced extracellular polysaccharide, the key component of the biofilm matrix. Transcriptional analysis further revealed that PFB252 at sub-inhibitory concentrations downregulated critical biofilm-associated genes. PFB252 exhibited strong antimicrobial efficacy in dairy applications. It could reduce MRSA counts in milk from 10[3] to < 10 cfu/mL within 4 d at MIC and maintaining suppression in cheese below 10[2] cfu/g over 7 d. These properties highlight PFB252's potential as a natural bio-preservative for combating MRSA in food systems and offer a promising solution for food safety applications.

RevDate: 2025-10-23

Lu W, Sun S, Wang Q, et al (2025)

Acesulfame degradation within a methane-fed biofilm: a novel and efficient biodegradation route.

Journal of hazardous materials, 499:140152 pii:S0304-3894(25)03071-7 [Epub ahead of print].

Acesulfame (ACE), a persistent organic pollutant, is frequently detected across diverse aquatic environments, yet its environmental remediation remains challenging due to the inherently slow biodegradation. Here, we unveil a highly efficient ACE removal strategy using a methane-fed biofilm, achieving a degradation rate of 59.6 mg ACE/g VSS/h. Comprehensive analyses of transformation products (TPs) and toxicity profiles revealed that the biofilm mediated important and effective biodegradation pathways, promoting deep ACE degradation. Microbial community analysis, methane interruption experiments and pure culture studies implicated aerobic methanotrophs Methylococcus sp. and Methylomonas sp. as key players in ACE degradation. Metagenomic and metatranscriptomic analyses demonstrated that these methanotrophs exhibited high expression levels of particulate methane monooxygenase (pMMO) and cytochrome P450 monooxygenase (CYP450) genes within the biofilm community. Enzyme inhibition assays, combined with TP profiling, suggested that pMMO and CYP450 initiated the degradation of ACE. Scavenging experiments further suggested that hydroxyl radicals (•OH) generated through the catalytic activity of pMMO and CYP450 are crucial mediators in the ACE hydroxylation pathway. These findings provide the first evidence of ACE degradation in a methane-fed biofilm system, offering a promising and sustainable approach for the removal of recalcitrant organic contaminants from wastewater.

RevDate: 2025-10-23
CmpDate: 2025-10-23

Silva AR, Keevil CW, A Pereira (2025)

Legionella affects biofilm structural response to detachment upon shear stress increase.

Biofilm, 10:100323.

Poor hydraulic management at water systems is associated with an increased risk of Legionnaires' disease caused by Legionella. Stagnation periods, followed by sudden water flow, can promote biofilm detachment and the release of Legionella into the bulk water. Regardless of its importance, the simultaneous effects of shear stress on biofilm detachment and Legionella release into the bulk water remain poorly understood. This study investigates how shear stress affects biofilms containing Legionella pneumophila in terms of: a) biofilm detachment, b) release of L. pneumophila into the bulk phase, and c) shifting of L. pneumophila into the viable but nonculturable (VBNC) state. Pseudomonas fluorescens biofilms were formed in a Center for Disease Control (CDC) biofilm reactor at 125 RPM and spiked with L. pneumophila. After 6 days, the system was set for 48 h to stagnation before flow was resumed at rotational velocities of 125, 225, and 400 RPM, corresponding to turbulent regimes with Reynolds numbers of 1552, 2794 and 4966, respectively. Biofilm properties, L. pneumophila viability, culturability, and spatial distribution were monitored. Results show that biofilms containing L. pneumophila maintained a similar basal thickness (12 μm) despite the detachment of the upper layers under different shear stresses. L. pneumophila, located at the bottom of the biofilm, remains surface-attached after biofilm detachment and seems to enhance the cohesiveness of these layers compared to P. fluorescens biofilms. On the contrary, when Legionella is not present, biofilm detachment increases with the increase of applied shear forces. All tested rotational velocities triggered L. pneumophila to enter the VBNC state in the bulk phase, while biofilm-associated VBNC cells were only observed at 400 RPM. Finally, the contribution of the present work to Legionella control practices in water systems is discussed, highlighting the important insights that biofilms can provide in this context.

RevDate: 2025-10-22
CmpDate: 2025-10-22

Matte J, Fonseca S, Robidoux J, et al (2025)

Monitoring of Staphylococcus epidermidis biofilm formation on platelet storage bag surfaces.

PloS one, 20(10):e0333558.

Platelet concentrates (PCs) are stored at 20-24˚C in a biologically favorable environment that may support bacterial growth. Staphylococcus epidermidis, a typical contaminant, can form biofilms in PCs, complicating detection and increasing the risk of transfusion-transmitted bacterial infections. The material composition and surface texture of PC storage bags may influence biofilm formation. The impact of different PC storage bag materials on S. epidermidis biofilm formation was evaluated using the ISO 4768:2023(E) crystal violet (CV) assay. Four surface conditions were tested: polyvinyl chloride (PVC) plasticized with n-butyryl-tri(n-hexyl)-citrate (BTHC) - both smooth and rough sides, PVC plasticized with tri-(2-ethylhexyl)-trimellitate (TEHTM) and ethylene-vinyl acetate (EVA). Coupons and bags made from each material were used in the experiments. Biofilm-positive S. epidermidis was cultured in tryptic soy broth (TSB), PCs and plasma and added on plastic coupons under static conditions or directly in the bags with agitation. Bacterial enumeration and CV assay were performed on days 2, 5, and 7. In TSB, EVA coupons significantly formed more biofilm than the smooth side of PVC-BTHC or TEHTM over seven days. In PCs, more biofilm formed on the rough side of PVC-BTHC coupons than the smooth side, with no other differences between plastics, suggesting similar biofilm amount across PC bag materials in the presence of platelets. No biofilm was detected on coupons in plasma. Under continuous agitation and reduced oxygen levels, only the rough side of PVC-BTHC showed significant biofilm formation in TSB in PC storage bags over seven days. These findings highlight the need for standardized biofilm testing and suggest that some plastics are more conducive to biofilm formation under static conditions. However, during blood bank storage (i.e., continuous agitation and reduced oxygen levels), biofilm formation is limited, regardless of the platelet bag material, thereby reducing the risk of undetected bacterial contamination.

RevDate: 2025-10-22
CmpDate: 2025-10-22

Narimisa N, Khoshbayan A, Masjedian Jazi F, et al (2025)

The Role of Carbenicillin as an Inhibitor of the Biofilm Regulator CsgD in Salmonella Typhimurium.

MicrobiologyOpen, 14(5):e70081.

Salmonella Typhimurium, a major foodborne pathogen, forms biofilms that enhance its environmental persistence and resistance to antibiotics, presenting significant public health challenges. The CsgD protein, a key transcriptional regulator, orchestrates biofilm formation by regulating curli fimbriae and cellulose production. This study aimed to identify and evaluate potential CsgD inhibitors to disrupt S. Typhimurium biofilms using a combination of computational and experimental methodologies. Molecular docking was performed to screen 145 FDA-approved antibiotics from DrugBank against the CsgD protein. Carbenicillin, identified as a top candidate, was further analyzed through 100 ns molecular dynamics simulations to assess the stability of the carbenicillin-CsgD complex. Experimental evaluations determined the minimum biofilm inhibitory concentration (MBIC), and minimum biofilm eradication concentration (MBEC) of carbenicillin against S. Typhimurium isolates. Biofilm structure and curli production were examined using scanning electron microscopy (SEM) and Congo red agar assays, respectively. Molecular docking revealed carbenicillin's high binding affinity to CsgD. Molecular dynamics simulations confirmed the structural stability of the carbenicillin-CsgD complex. Experimental assays established MBIC and MBEC at 1 and 4 μg/mL, respectively. SEM analysis showed morphological changes and disrupted biofilm architecture at 0.5-1 μg/mL carbenicillin, while Congo red agar assays demonstrated dose-dependent suppression of curli production. Carbenicillin exhibits significant potential as a CsgD-targeted anti-biofilm agent, providing a foundation for novel therapeutic strategies to combat S. Typhimurium infections and address their public health burden.

RevDate: 2025-10-21

Wang Z, Wang R, Jiang S, et al (2025)

SinI and SinR function differently in biofilm formation, rhizosphere colonization, and biocontrol efficacy between Bacillus velezensis and B. subtilis.

Microbiology spectrum [Epub ahead of print].

UNLABELLED: Numerous Bacillus species, in particular B. subtilis and B. velezensis, are usually used as effective biocontrol agents against plant diseases, leveraging their ability to form biofilms for robust colonization of the rhizosphere. In B. subtilis, SinI positively influences biofilm formation, rhizosphere colonization, and biocontrol efficacy, whereas SinR has a negative impact. To boost the biocontrol efficacy of B. velezensis R9 against tobacco bacterial wilt, we engineered the deletion of sinI and sinR genes in this strain, respectively. Contrary to expectations, deleting sinR impaired biofilm formation, rhizosphere colonization, plant resistance induction, and bacterial wilt control. Conversely, the R9ΔsinI strain showed notably enhanced biofilm, colonization, and biocontrol efficacy relative to both R9 and R9ΔsinR strains. Complementing R9ΔsinI with sinI and R9ΔsinR with sinR confirmed that SinI negatively and SinR positively regulate biofilm formation in R9, regardless of originating from B. velezensis or B. subtilis. By contrast, sinI knockout in B. subtilis M6 caused a marked decline in biofilm formation but could be partially reversed by complementary expression of sinI whether it was from B. subtilis or B. velezensis. Conversely, sinR knockout in M6 sharply decreased biofilm formation. In summary, SinI negatively and SinR positively regulate biofilm formation in B. velezensis, contrasting with their roles in B. subtilis. Consequently, deleting sinI, not sinR, in B. velezensis enhances biofilm formation, promoting root colonization, plant resistance, and disease control.

IMPORTANCE: Bacillus species, exemplified by B. subtilis as a model organism for Gram-positive bacteria, have been extensively studied, particularly regarding biofilm formation. Biofilms represent a form of quorum sensing in microbial communities, and the biocontrol efficacy of Bacillus species in the rhizosphere, against plant pathogens, hinges on their biofilm-forming capabilities. In B. subtilis, the regulatory proteins SinI and SinR are known to have opposing functions in biofilm formation, with SinI facilitating and SinR inhibiting biofilm development. Drawing from this foundational knowledge, we endeavored to knock out the sinR gene in B. velezensis, a biocontrol bacterium, to enhance biofilm formation and, consequently, its colonization of the rhizosphere and biocontrol efficacy. Unexpectedly, the deletion of sinR reduced the bacterium's proficiency in biofilm formation and its ability to colonize the rhizosphere, resulting in a decrease in biocontrol effectiveness. On the contrary, the knockout of sinI promoted biofilm formation, bolstered the strain's colonization capacity in the rhizosphere, and thus fortified its biocontrol efficacy. These findings underscore that SinI and SinR exert divergent, even antithetical effects in Bacillus species. Insights gleaned from B. subtilis research cannot be extrapolated to encompass all Bacillus species, at least not B. velezensis, indicating the need for species-specific investigations.

RevDate: 2025-10-21

Silva ML, Lopes FES, Soares PHP, et al (2025)

Aurein 1.2 analogues as promising agents against Candida parapsilosis: insights into mechanism and biofilm disruption.

Future microbiology [Epub ahead of print].

INTRODUCTION: Candida parapsilosis has emerged among invasive fungal infections, boming an alarming problem for human health. Recent studies have focused on antimicrobial peptides and their derivatives, such as the Aurein family, as a new approach to developing cutting-edge antifungal agents.

OBJECTIVE: This study aimed to evaluate the antifungal potential of Aurein 1.2 (Au) and two modified analogs, K-aurein (K-au) and D-aurein (D-au), containing an additional lysine or aspartic acid residue, respectively, at the N-terminal of the native peptide.

MATERIALS & METHODS: To this, antifungal activity, time of action by time-kill curve, ergosterol-binding analysis in vitro and in silico, and antibiofilm assays were performed. Results: We found that K-au demonstrated the lowest cytotoxicity and the greatest antifungal activity compared to other tested peptides. K-au showed MIC values ranging from 62.5 to 125 μg/mL and time of action fungicide between 60 and 180 min. Molecular docking indicated strong interaction with ergosterol, particularly for K-au, supporting a membrane-targeting mechanism. Biofilm assays demonstrated that the peptides inhibited biofilm formation by up to 80% and were effective against mature biofilms, as confirmed by ultrastructural analysis.

CONCLUSION: These findings highlight Au-derived peptides as promising molecules against C. parapsilosis.

RevDate: 2025-10-21
CmpDate: 2025-10-21

D'Amico R, Casillo A, Olimpo D, et al (2025)

Capsular polysaccharide from Psychrobacter sp. TAE2020: An unusual amino sugar-enriched macromolecule with anti-biofilm and emulsification activities.

Carbohydrate polymers, 370:124484.

Extracellular polysaccharides exhibit a broad range of biological activities, among which antibiofilm activity is of particular interest due to the growing clinical importance of biofilm-related infections. Psychrobacter sp. TAE2020, a marine Gram-negative bacterium, produces a molecular complex named CATASAN, endowed with antibiofilm properties. The aim of this study is the identification and structural characterisation of the polysaccharidic component of the CATASAN complex. Moreover, the interest was in finding the structural features possibly responsible for the anti-biofilm and emulsifying activities. Here, it has been demonstrated that the polysaccharide within the CATASAN complex corresponds to the capsular polysaccharide produced by Psychrobacter sp. TAE2020. The detailed primary structure of this CPS is here reported, which is composed of a tetrasaccharide repeating unit containing two residues of α-D-galactosamine, one residue of α-D-2,4-diacetamido-2,4,6-trideoxy-α-glucopyranose, and the unusual α-L-gulosamine. The physical properties of the CPS, such as its ability to adhere to hydrophobic surfaces and exhibit emulsifying activity, suggest that this polymer is a promising candidate for alternative anti-infective applications in clinical settings.

RevDate: 2025-10-21
CmpDate: 2025-10-21

Kashi PA, Bachlechner C, Huc-Mathis D, et al (2025)

A porous 3D biofilm-inspired alginate/gellan hydrogel fabricated via dual-wavelength UV-crosslinking printer: Structural and rheological properties.

Carbohydrate polymers, 370:124246.

The advancement of additive manufacturing for biopolymers with spatially tailored properties remains challenging, particularly in multi-material structures. Traditional methods relying on automated sample swapping compromise production speed and interlayer adhesion. Critically, existing biofilm models predominantly use 2D formats that fail to replicate essential 3D microenvironments for structural development and antimicrobial resistance-limiting their physiological relevance. To address both manufacturing and modeling limitations, we introduce a novel dual-wavelength in-place UV crosslinking technique using chemo-selective irradiation (UV-A:390 nm and UV-C:260 nm) in combination with a Norrish Type I photoinitiator to fabricate multi-material macroporous biofilm-inspired architecture with enhanced mechanical and rheological properties, as well as effective 3D architectures for biofilm simulation. An alginate/gellan-inspired hydrogel mimicking biofilm materials enables stiffness modulation via photosensitization tuning. Results demonstrated UV-A yielded softer, flexible networks while UV-C produced stiffer, elastic structures. The application of Norrish type I photoinitiators in combination with in-place UV irradiation-coupled with bioprinter considerably broadened the achievable thermo-mechanical and cytocompatibility with improved build efficiency, overcoming traditional UV-curing limitations for functional multi-material components in advanced manufacturing and physiologically relevant biofilm modeling.

RevDate: 2025-10-20

Klerk DH, CP Sodhi (2025)

Biofilm probiotics for NEC: promise, pitfalls, and pathways to translation.

Pediatric research [Epub ahead of print].

RevDate: 2025-10-20

Qi J, Li M, Zhu K, et al (2025)

Peroxymonosulfate-activated sludge conditioning coupled with membrane aerated biofilm reactor: mechanisms of extracellular polymeric substance reconfiguration, nitrogen metabolic shifts, and greenhouse gas mitigation.

Bioresource technology pii:S0960-8524(25)01494-4 [Epub ahead of print].

The study establishes the synergistic integration of peroxymonosulfate (PMS)-activated sludge conditioning with Membrane Aerated Biofilm Reactor (MABR) technology for co-treatment of sludge and wastewater. Electron Paramagnetic Resonance (EPR) and 3D- Excitation-Emission Matrix (3D-EEM) spectroscopy revealed that PMS conditioning (1 mmol/g-TS) induced sludge lysis (5.14 %) and generated SO4[-] and OH, triggering dynamic Extracellular Polymeric Substance (EPS) subfraction reconstruction and enhancing dewaterability. While treating the PMS-conditioned supernatant in MABRs drove significant shifts in nitrogen metabolism, evidenced by nitrite accumulation (2.4 mg/L) and nitrous oxide (N2O) emission (+0.198 ppm) with residual PMS 120 mg/L. 16S rRNA sequencing revealed that Acinetobacter-driven aerobic denitrification and Candidatus_Brocadia-mediated Anammox played substantial roles in the MABR system. Untargeted metabolomics identified the microbial carbon and nitrogen metabolism primarily via L-α-amino acids. These findings establish the theoretical foundation for the efficient co-treatment of sludge and wastewater using MABR coupled with Advanced Oxidation Processes (AOPs).

RevDate: 2025-10-20
CmpDate: 2025-10-20

Ma R, Wang P, Zhang Y, et al (2025)

Inhibition of Streptococcus mutans biofilm formation and virulence by natural extract Stevioside.

Frontiers in microbiology, 16:1675322.

OBJECTIVE: This study aimed to investigate the effect of the natural extract of Stevioside on biofilm formation and cariogenic virulence factors of Streptococcus mutans (S. mutans), and to explore its mechanism of action preliminarily, with the goal of identifying a safer and more effective non-cariogenic sweetener.

METHODS: The inhibitory effect of Stevioside on the growth of S. mutans biofilm was detected by crystal violet staining. The acid production capacity of S. mutans biofilms was evaluated by measuring the pH values and lactic acid contents. The bacterial viability within the biofilms was determined using the plate counting method. Scanning electron microscopy (SEM) and laser confocal microscopy (CLSM) were used to observe the biofilm structure, and the fluorescence intensity of live and dead bacteria and biofilm thickness were further analyzed. The anthrone sulfuric acid method quantified the production of Soluble Extracellular Polysaccharide (SEPS) and Insoluble Extracellular Polysaccharide (IEPS) in biofilm. Furthermore, real-time fluorescence quantitative PCR (RT-qPCR) was used to detect the expression of genes related to biofilm growth, acid production, acid tolerance, exopolysaccharide synthesis, two-component signal and quorum sensing.

RESULTS: Stevioside significantly inhibited the formation of S. mutans biofilm, and reduced acid production, bacterial activity and EPS production. SEM and CLSM confirmed the reduction of the dense three-dimensional structure of biofilm. In addition, compared with sucrose, the expression of related genes was down-regulated in Stevioside.

CONCLUSION: Stevioside inhibits S. mutans virulence factors and biofilms and is a promising natural sucrose substitute for preventing dental caries.

RevDate: 2025-10-20

Sarkar S, Tripathi V, Sadhukhan S, et al (2025)

An innovative strategy to treat pathogenic biofilm-associated infections in vitro and in vivo using guanidinium-linked neomycin lipidation.

RSC medicinal chemistry [Epub ahead of print].

To overcome neomycin's limited efficacy against complex Gram-positive and Gram-negative co-infections, we have developed a novel guanidinium-linked neomycin-lipid conjugate (guanidino Neo-lipid). This multifunctional construct integrates three synergistic components: a neomycin core for ribosomal targeting, a hydrophobic lipid chain to facilitate membrane interaction and cellular uptake, and a cationic guanidinium moiety that enhances electrostatic binding to negatively charged bacterial membranes. The resulting conjugate demonstrates significantly improved antibacterial activity in liquid cultures and effectively disrupts biofilm formation. This approach offers a promising therapeutic strategy for treating persistent infections caused by both Gram-positive and Gram-negative pathogens, including co-infective scenarios.

RevDate: 2025-10-19

Dabul ANG, Samaniego LVB, Cortez AA, et al (2025)

Comparison of Biofilm-Degrading Activities of Two Glycoside Hydrolase Family 20 Enzymes against Clinical and Veterinary β-1,6-poly-N-acetyl-D-glucosamine-dependent Staphylococcus aureus Isolates.

Acta biomaterialia pii:S1742-7061(25)00778-0 [Epub ahead of print].

Biofilms shield microbial communities from various environmental threats, including antimicrobial agents. Such protection renders bacterial cells within biofilms more resistant to antimicrobial agents than their planktonic counterparts. Degradation of the exopolysaccharides of the biofilm matrix using glycoside hydrolases (GH) strongly increases the efficacy of antimicrobials against biofilms. Staphylococcus aureus is a leading cause of infections in both humans and animals, with many of its strains producing biofilms rich in β-1,6-N-acetyl-D-glucosamine (PNAG), the primary component of the extracellular matrix of their biofilms. In this study, we recombinantly produced and biochemically characterized two glycoside hydrolases from GH20 family, ApGH20 and ChGH20, both of which specifically target PNAG. These enzymes effectively degraded and inhibited biofilm formation of S. aureus human clinical strain which produces a robust PNAG-based biofilm. Both enzymes also demonstrated high activity against several veterinary S. aureus isolates. All of these isolates have been sequenced and analyzed. Notably, ApGH20 exhibited nearly three orders of magnitude higher activity than ChGH20 in degrading S. aureus biofilm, yet both enzymes similarly enhanced the ability of gentamicin to kill human isolate of S. aureus, albeit at different dosages. These findings further demonstrate that application of glycoside hydrolases, when combined with antimicrobial agents, is a promising strategy for treating infections caused by pathogenic S. aureus strains. STATEMENT OF SIGNIFICANCE: Antimicrobial resistance is a very significant health problem, resulting in millions of deaths worldwide. Pathogenic bacteria become resistant to antibiotics using various mechanists, one of which is to protect themselves by biofilms. Staphylococcus aureus is a leading cause of infections in both humans and animals, with many of its strains relying on β-1,6-N-acetyl-D-glucosamine (PNAG) polysaccharide as an important part of their biofilms. Here we produced two glycoside hydrolase enzymes which specifically target PNAG. We showed that the enzymes effectively degraded and also prevented biofilm formation of S. aureus human clinical and several veterinary isolates. Both enzymes similarly enhanced efficiency of gentamicin against S. aureus, albeit at different dosages, which might hold promise to treat infections caused by these pathogenic bacteria.

RevDate: 2025-10-19

Randmäe K, Lorenz K, Putrinš M, et al (2025)

Preparing a Dual-Species In Vitro Biofilm Model for Testing Antibiofilm Efficacy.

Molecular pharmaceutics [Epub ahead of print].

All wounds are contaminated, and there is a risk of developing an infection. Furthermore, most wounds contain biofilm and are contaminated by two bacteria, termed dual-species, or more bacteria, termed polybacterial biofilms. New antibacterial and antibiofilm wound care products are constantly being developed to combat this problem. There is a need to develop more biorelevant and reproducible models to test the efficacy of these wound care products. We used an electrospun (ES) gelatin-glucose matrix (Gel-Gluc) as an artificial skin substrate for dual-species biofilm formation using wound pathogens Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa, combining them in pairs. When analyzing the biofilms, selective agars were used to differentiate various bacteria from one another while counting. The developed method supported the growth of dual-species biofilm that contained both bacteria up to 10[8] CFU/Gel-Gluc after 24 h. Over 48 h, there was a decrease in the number of S. aureus in the biofilms. Confocal microscopy imaging allowed monitoring of the location of bacteria in the Gel-Gluc and proved that different species were located closely together. ES polycaprolactone (PCL) fibrous wound dressings containing chloramphenicol (CAM) or ciprofloxacin (CIP), or their pristine analogs, were used to test the model. Both ES fibrous wound dressings were effective in preventing dual-species biofilm formation. PCL-CIP fibrous dressing was also effective in treating biofilms. The efficacy of treatment of E. coli varied in different dual-species combinations of E. coli. The developed dual-species biofilm model on artificial skin (Gel-Gluc) supported the successful growth of different bacterial combinations and proved to be suitable for testing the efficacy of ES fibrous wound dressings in preventing and treating biofilms.

RevDate: 2025-10-18

Régnier A, Chalivat É, Chesnais V, et al (2025)

Increased biomass and viable but nonculturable state following benzalkonium chloride exposure in Vibrio parahaemolyticus biofilm, independent of the disinfectant resistome.

International journal of food microbiology, 445:111490 pii:S0168-1605(25)00435-0 [Epub ahead of print].

Vibrio parahaemolyticus is a halophilic pathogen capable of persisting in industrial settings through biofilm formation, which enhances its resistance to disinfectants. This study characterized the resistome of 39 V. parahaemolyticus strains, focusing on antimicrobial resistance genes (ARGs) linked to disinfectant tolerance, and assessed the influence of the gene qacEΔ1 in biofilm formation and entry into the viable but nonculturable (VBNC) state under industrial benzalkonium chloride (BAC) concentrations ranging from 31.25 to 500 μg/mL. Whole-genome sequencing (long and short read) revealed 21 encoded ARGs localized on the chromosomes, including 19 from the resistance nodulation cell division (RND) efflux pump family and the vmrA gene (MATE family), all highly conserved. Notably, the qacEΔ1 gene, a small multidrug resistance (SMR) type efflux pumps conferring quaternary ammonium compound resistance, was detected chromosomally for the first time in V. parahaemolyticus, positioned near mobile genetic elements (20kbp), indicating dissemination potential. BAC minimal biofilm eradication assays showed increased biomass in qacEΔ1 negative strains. qPCR, PMA-qPCR, and enumeration demonstrated that biofilms were composed of dead cells (≈20 %), VBNC cells (≈80 %), and an extra cellular matrix rich in extra cellular DNA. Biomass increases were not significant in qacEΔ1 positive strains, suggesting that absence of qacEΔ1 promotes matrix overproduction to limit disinfectant penetration. On the other hand, qacEΔ1 presence favours active BAC efflux, reducing adaptive matrix response, but could increase energetic costs and thus affecting biomass. These findings indicate that BAC at industrial concentrations (375 μg/mL) fails to eradicate V. parahaemolyticus biofilms without mechanical action and induces VBNC states, emphasizing the need to reassess disinfection strategies by combining the use of BAC with mechanical action to ensure effective microbiological risk control.

RevDate: 2025-10-18

Li C, Tan L, Ma Y, et al (2025)

A bacteriophage with dual host specificity for canine and porcine Bordetella bronchiseptica: Characterization and biofilm disruption potential.

Virology, 613:110714 pii:S0042-6822(25)00328-9 [Epub ahead of print].

Bordetella bronchiseptica is a pathogen responsible for canine infectious tracheobronchitis (kennel cough) and porcine atrophic rhinitis, and it can cause respiratory infections in a variety of mammalian hosts. In recent years, the extensive use of antibiotics has resulted in increasingly severe antibiotic resistance, consequently driving significant interest in bacteriophages as a potential alternative to antibiotics. In this study, bacteriophage PBb001 isolated from swine farm wastewater in Yantai, Shandong, exhibited lytic activity against Bordetella bronchiseptica, including strains derived from canine and swine hosts. Bacteriophage PBb001 exhibited a latent period of 30 min and a burst size of approximately 323 plaque-forming units (PFU) per cell. The phage exhibited robust stability across a temperature range of 4-60 °C and pH conditions of 3-11, with an optimal multiplicity of infection (MOI) of 0.1. Genomic analysis revealed that PBb001 possesses a linear double-stranded DNA genome of 44,808 bp, with no lysogeny genes, virulence factors, or antibiotic resistance genes detected. In vitro antibacterial assays showed that PBb001 significantly reduced optical density (OD600, reflecting bacterial growth inhibition) and viable bacterial counts in planktonic cultures. Additionally, PBb001 effectively suppressed biofilm formation and disrupted pre-existing biofilms, as evidenced by reduced OD595 values and decreased viable bacterial counts in biofilm-associated assays. These results collectively suggest that PBb001 holds significant potential for controlling B. bronchiseptica infections and represents a potential candidate for further development as an antibiotic alternative.

RevDate: 2025-10-18

Kasto S, PI Higgs (2025)

Characterization of a Regulatory Network Promoting Cell Fate Segregation in the Myxococcus xanthus Biofilm.

Molecular microbiology [Epub ahead of print].

Most bacterial populations exhibit phenotypic heterogeneity to increase fitness in rapidly changing environmental conditions. Myxococcus xanthus is an environmental bacterium that displays pronounced phenotypic heterogeneity in its complex lifecycle. Under nutrient limitation, M. xanthus produces a specialized biofilm in which cells segregate into two spatially distinct fates: fruiting bodies filled with spores and a persister-like peripheral rod population. Little is known about the regulatory mechanisms controlling peripheral rods. To begin to investigate this cell fate segregation mechanism, we focused on the EspAC signaling system, which controls the accumulation of MrpC, a central transcription factor necessary to induce fruiting body formation. Single-cell reporters and in situ confocal microscopy demonstrated that expression of the esp genes is enriched in the peripheral rods. We identified three transcription factors necessary for espAC transcriptional control: MrpC, FruA, a transcription factor that coordinates sporulation within fruiting bodies, and the xenobiotic response element, Xre0228. We demonstrate that MrpC directly activates espA and espC; FruA represses espC but not espA; and Xre0228 activates espA but represses espC. These genetic interactions fit common network motifs that promote or stabilize phenotypic heterogeneity. We propose a model by which cell fate segregation is directed, stabilized, and tuned to environmental conditions.

RevDate: 2025-10-18

Li T, Li X, Su J, et al (2025)

Development of a biofilm reactor using nano Fe3O4-modified biochar and red mud: Enhanced synergistic removal of nitrate, cadmium, and acetaminophen.

Environmental research, 287:123142 pii:S0013-9351(25)02395-3 [Epub ahead of print].

Insufficient C/N ratio and a wide range of pollutants tend to limit the treatment of secondary effluents from wastewater treatment plants (WWTPs). In this study, a biofilm reactor was established to achieve nitrate (NO3[-]) removal in WWTPs, based on ferrous-driven denitrification. The bioreactor was composed of nano-Fe3O4 modified biochar and red mud (nano-Fe3O4@BC-RM) with the introduction of Zoogloea sp. ZP7. NO3[-] removal efficiency (NRE) achieved 97.04 % when HRT = 6 h, C/N = 1.5, pH = 7, and still maintained more than 80 % in the presence of cadmium (Cd[2+]) and acetaminophen (ACT). Moreover, the removal of Cd[2+] and ACT was mainly through adsorption by the extracellular polymeric substances (EPS) and bio-iron precipitation. The large enrichment of microorganisms with denitrification and iron cycling functions in the biological community maintained the stable operation of the bioreactor. This study provides a valuable experience for the treatment of low C/N ratio wastewater and an innovative solution to solid waste.

RevDate: 2025-10-17

Zhang Y, Zhou L, Wu M, et al (2025)

Coupled syngas fermentation to multiple oxidized contaminants reduction in a membrane biofilm reactor.

Water research, 288(Pt B):124749 pii:S0043-1354(25)01652-5 [Epub ahead of print].

Multiple oxidized contaminants (MOC) frequently coexist in water sources, posing significant human health risks. Major challenges in the biological reduction of MOC include the lack of effective carbon sources and competition for a sole electron donor. This study demonstrates the feasibility of using syngas fermentation in a lab-scale membrane biofilm reactor (MBfR) to provide dual electron donors, volatile fatty acids (VFAs) and H2, to support simultaneous removal of nitrate, selenate, bromate, and perchlorate. MBfR was employed for efficient gas delivery, achieving complete MOC removal with non-toxic end products (N2, Se[0], Br[-], and Cl[-]) generated over 200 days of operation. In situ batch tests revealed that MOC reduction was synergistically driven by H2 and VFAs generated via gas fermentation. H2 primarily facilitated bromate reduction, VFAs enhanced perchlorate reduction, while nitrate and selenate were reduced by both electron donors. Maximal removal rates reached 108.1 mg N/L/d, 6.9 mg Br/L/d, 5.5 mg Cl/L/d, and 5.4 mg Se/L/d when both H2 and VFAs were utilized. High-throughput 16S rRNA gene amplicon sequencing suggested gas fermenters (Acetobacterium and Clostridium), autotrophic MOC-reducing taxa (e.g., Shewanella), and heterotrophic MOC-reducing taxa (e.g., Clostridium, Desulfovibrio) as the dominant community members, underscoring their roles in syngas conversion and contaminant reduction. These findings highlight the potential of integrating syngas fermentation in MBfRs as an efficient strategy for simultaneous MOC removal, providing a promising approach for water remediation.

RevDate: 2025-10-17
CmpDate: 2025-10-17

Cheng X, Song J, Hu Q, et al (2025)

Carbonizing technology enables Sanguisorbae Radix to inhibit yeast-to-hypha differentiation and biofilm formation in Candida albicans.

PloS one, 20(10):e0334659 pii:PONE-D-25-10562.

Sanguisorbae Radix (SR) has been employed as an herbal medicine over centuries. Charred SR (CSR), acquired via carbonization after the charred stir-frying of SR, demonstrates superior antimicrobial activity compared to SR. The aim of the study was to identify how carbonizing technology enhanced the ability of SR to inhibit the transformation from yeast to hypha and biofilm formation in C. albicans. In this paper, a vulvovaginal candidiasis (VVC) mouse model was used to evaluate the therapeutic effects. After CSR treatment, VVC mouse models nearly eliminated hyphal C. albicans adhering to the vaginal mucosa. The inhibitory activities of CSR on C. albicans biofilm formation and hyphal growth were assessed through quantitative biofilm analysis, morphological observations, and gene expression studies in vitro. Since the hyphal form signifies the initiation of biofilm development, this study confirmed CSR's remarkable inhibitory effect on C. albicans biofilm formation and hyphal growth. These effects were significantly weaker with SR. Additionally, the impact of carbonization on the composition of active compounds was analyzed. Carbonization significantly increased the content of ellagic acid (EA) and pyrogallic acid (PYG) by 7.44-fold and 28.09-fold, respectively. Both EA and PYG inhibited C. albicans biofilms and hyphal growth, with EA showing a more pronounced inhibitory effect. Finally, we concluded that carbonization technology enables SR to inhibit the yeast-to-hypha transition and biofilm formation in C. albicans by increase the levels of EA and PYG. EA was identified as the primary bioactive compound responsible for CSR's anti-biofilm effects.

RevDate: 2025-10-17

Saman , Siddique AB, Aslam B, et al (2025)

Biofilm Formation and Antibiotic Resistance in Uropathogenic Escherichia coli: A Molecular Characterization and Antibiogram Study.

Microbial drug resistance (Larchmont, N.Y.) [Epub ahead of print].

Biofilm formation is a key virulence factor in urinary tract infections, and Escherichia coli (E. coli) serves as a prominent causative agent, more resistant to antimicrobial agents. This study focused on isolation and phenotypic and genotypic characterization of E. coli from urine samples on the basis of their biofilm-forming capacity. In the present study, a total of 804 human urine samples were collected from different clinical facilities of Faisalabad. After phenotypic and genotypic affirmation, biofilm forming potential of uropathogenic E. coli (UPEC) was determined by using microtiter plate assay (MPA) and the Congo red agar method. Antimicrobial susceptibility testing was conducted, and a comparison was executed between biofilm formers and non-formers. Biofilm production by the MPA and Congo red agar methods was 88% and 68%, respectively. UPEC isolates showed maximum resistance to amoxicillin-clavulanate (97%), cefoparazone (93%), cefotaxime (91%), and ampicillin (90%). Significant association between resistance to antibiotic and biofilm formation with p value <0.05 was observed in case of piperacillin-tazobactam, imipenem, meropenem, amikacin, norfloxacin, nitrofurantoin, polymyxin B, and nalidixic acid. Biofilm producer strains were progressed for molecular characterization using polymerase chain reaction for biofilm-forming genes including fimH, csgA, bcsA, agn43, papC, and focG, which showed prevalence of 89% (118/132), 87% (116/132), 86% (114/132), 81% (107/132), 47% (61/132), and 33% (43/132), respectively.

RevDate: 2025-10-17

Seo K, Moon J, Bhat R, et al (2025)

Cationic Polymer for Aligner and Oral Biofilm Removal via Osmotic Mechanism.

Journal of dental research [Epub ahead of print].

Dental caries caused by cariogenic biofilms is a significant challenge in modern dentistry, especially with aligner treatments, where biofilms can easily build up during prolonged use and lead to serious risks. Traditional antimicrobial methods focus on bacterial killing and often overlook the vital task of removing the biofilm matrix, allowing the quick reattachment of bacteria. In this study, we introduce an osmotic-driven biofilm removal strategy that harnesses osmotic dynamics to remove entire biofilm structures physically. Internal osmotic pressure is generated by a precisely designed cationic copolymer, triggering controlled detachment of the biofilm matrix. When tested in vitro on Streptococcus mutans biofilms grown on dental aligners and in hard-to-reach interproximal spaces, our method eliminated biofilms more efficiently than traditional cleaning methods. The technique showed concentration-dependent cytotoxicity, highlighting the need for further polymer optimization. Overall, our osmotic-driven biofilm removal strategy significantly advances biofilm control strategies, offering a novel solution for improving oral health and presenting a potential physical removal method for medical settings.

RevDate: 2025-10-16
CmpDate: 2025-10-17

Guerrero-López F, Ortiz Y, Merino-Mascorro JÁ, et al (2025)

Subinhibitory Concentrations of Oxacillin Alter Motility, Biofilm Production, and Transformation Capability of the Oxacillinase-Producing Acinetobacter baumannii.

Current microbiology, 82(12):562.

Subinhibitory concentrations of various antibiotics can exacerbate microbial virulence. Acinetobacter baumannii is often resistant to oxacillin; however, the effect of low oxacillin concentrations on oxacillinase-producing bacteria remains unclear. Herein, oxacillinase producer A. baumannii ATCC-strains 2093 (motile) and 19606 (non-motile) were pre-exposed to sub-bactericidal concentrations (subMBC) of oxacillin (0.25, 0.5, and 1.0 mg/mL) and incubated at 37 °C. Growth kinetics, twitching and swarming-like motility, biofilm formation, exopolysaccharide production, transformation capability, and gene expression were determined. All oxacillin subMBC conditions exerted bacteriostatic effects in both strains. Pre-exposing the motile strain with 0.25 and 0.5 mg/mL of oxacillin for 1 h increased the twitching motility (4.2 ± 0.3 cm; control = 3.5 cm), whereas pre-exposure for 2 h it increased swarming-like motility (2.95 ± 0.15 cm; control = 2.7 cm). This strain also increased the biofilm production by effect of all 6 h-oxacillin subMBC treated bacteria (≤ 1.42 Biofilm Formation Index (BFI); control = 0.6 BFI), whereas the strain 19606 reduced biofilm up to 1 BFI (control = 2 BFI). The antibiotic also reduced the exopolysaccharide production in almost all treated cells from both strains. The transformation efficiency (TE) of strain 19606 increased X̄ = 19 ± 11% more than the control by effect of all DNA and oxacillin conditions studied; however, the TE for strain 2093 was lower than the control. The expression of genes for resistance (bla-OXA), twitching (pilA/tonB) and swarming-like motilities (dat/ddc), and biofilm production (csuE) were altered by the oxacillin subMBC. Overall, exposure of oxacillinase-producing A. baumannii to oxacillin subMBC increases several virulence factors, representing a potential public health risk.

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RJR Experience and Expertise

Researcher

Robbins holds BS, MS, and PhD degrees in the life sciences. He served as a tenured faculty member in the Zoology and Biological Science departments at Michigan State University. He is currently exploring the intersection between genomics, microbial ecology, and biodiversity — an area that promises to transform our understanding of the biosphere.

Educator

Robbins has extensive experience in college-level education: At MSU he taught introductory biology, genetics, and population genetics. At JHU, he was an instructor for a special course on biological database design. At FHCRC, he team-taught a graduate-level course on the history of genetics. At Bellevue College he taught medical informatics.

Administrator

Robbins has been involved in science administration at both the federal and the institutional levels. At NSF he was a program officer for database activities in the life sciences, at DOE he was a program officer for information infrastructure in the human genome project. At the Fred Hutchinson Cancer Research Center, he served as a vice president for fifteen years.

Technologist

Robbins has been involved with information technology since writing his first Fortran program as a college student. At NSF he was the first program officer for database activities in the life sciences. At JHU he held an appointment in the CS department and served as director of the informatics core for the Genome Data Base. At the FHCRC he was VP for Information Technology.

Publisher

While still at Michigan State, Robbins started his first publishing venture, founding a small company that addressed the short-run publishing needs of instructors in very large undergraduate classes. For more than 20 years, Robbins has been operating The Electronic Scholarly Publishing Project, a web site dedicated to the digital publishing of critical works in science, especially classical genetics.

Speaker

Robbins is well-known for his speaking abilities and is often called upon to provide keynote or plenary addresses at international meetings. For example, in July, 2012, he gave a well-received keynote address at the Global Biodiversity Informatics Congress, sponsored by GBIF and held in Copenhagen. The slides from that talk can be seen HERE.

Facilitator

Robbins is a skilled meeting facilitator. He prefers a participatory approach, with part of the meeting involving dynamic breakout groups, created by the participants in real time: (1) individuals propose breakout groups; (2) everyone signs up for one (or more) groups; (3) the groups with the most interested parties then meet, with reports from each group presented and discussed in a subsequent plenary session.

Designer

Robbins has been engaged with photography and design since the 1960s, when he worked for a professional photography laboratory. He now prefers digital photography and tools for their precision and reproducibility. He designed his first web site more than 20 years ago and he personally designed and implemented this web site. He engages in graphic design as a hobby.

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Collection of publications by R J Robbins

Reprints and preprints of publications, slide presentations, instructional materials, and data compilations written or prepared by Robert Robbins. Most papers deal with computational biology, genome informatics, using information technology to support biomedical research, and related matters.

Research Gate page for R J Robbins

ResearchGate is a social networking site for scientists and researchers to share papers, ask and answer questions, and find collaborators. According to a study by Nature and an article in Times Higher Education , it is the largest academic social network in terms of active users.

Curriculum Vitae for R J Robbins

short personal version

Curriculum Vitae for R J Robbins

long standard version

RJR Picks from Around the Web (updated 11 MAY 2018 )