Biofilm最新文献

{"title":"PMA-qPCR to quantify viable cells in multispecies oral biofilm after disinfectant treatments","authors":"Sybille Schwendener,&nbsp;Manuela Flury,&nbsp;Joël Jenzer,&nbsp;Thomas Thurnheer,&nbsp;Lamprini Karygianni","doi":"10.1016/j.bioflm.2025.100281","DOIUrl":"10.1016/j.bioflm.2025.100281","url":null,"abstract":"<div><div>Conventional quantitative real-time PCR (qPCR) amplifies DNA from viable and dead cells, which can lead to an overestimation of live bacteria. Viability qPCR aims to eliminate DNA from membrane-compromised cells through treatment with propidium monoazide (PMA).</div><div>Here, we evaluated PMA-qPCR to enumerate viable cells of <em>Actinomyces oris</em>, <em>Fusobacterium nucleatum</em>, <em>Streptococcus oralis</em>, <em>Streptococcus mutans,</em> and <em>Veillonella dispar</em>. Five-species oral biofilms were grown on hydroxyapatite discs for 64 h. The biofilms were exposed to 0.2 % chlorhexidine (CHX) or 3 % sodium hypochlorite (NaOCl) for 2 min, either once before cell harvest at 64 h or six times during biofilm growth. The total and single species cells were quantified by culture (CFU) and qPCR from samples with and without PMA treatment before DNA extraction. For species-specific qPCR, TaqMan assays were applied. To determine total bacteria counts, a SYBR green qPCR was established using universal degenerative primers for the conserved <em>dnaK</em> gene.</div><div>For biofilms treated once with CHX, the addition of PMA led to a 1 to 1.6 log₁₀ reduction in PCR counts. This closely matched CFU and PMA-qPCR counts for total bacteria and all single species, except for <em>F. nucleatum</em>, where PMA-qPCR detected significantly more bacteria than culture. NaOCl treatment directly affected DNA and inhibited subsequent PCR amplification, even in samples without PMA. Single treatment of biofilms with 3 % NaOCl and six-fold exposure of biofilms to disinfectants resulted in no viable cell detection by culture. However, PMA did not completely prevent PCR amplification, indicating that disinfectant efficacy measured by viability PCR could be underestimated.</div></div>","PeriodicalId":55844,"journal":{"name":"Biofilm","volume":"9 ","pages":"Article 100281"},"PeriodicalIF":5.9,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143859281","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Integration of BrfS into the biofilm-controlling cascade promotes sessile Salmonella growth at low temperatures","authors":"Gonzalo Tulin ,&nbsp;Andrea A.E. Méndez ,&nbsp;Nicolás R. Figueroa ,&nbsp;Carol Smith ,&nbsp;María P. Folmer ,&nbsp;Diego Serra ,&nbsp;Joseph T. Wade ,&nbsp;Susana K. Checa ,&nbsp;Fernando C. Soncini","doi":"10.1016/j.bioflm.2025.100254","DOIUrl":"10.1016/j.bioflm.2025.100254","url":null,"abstract":"<div><div>Biofilm formation is stimulated by different stress-related physiological and environmental conditions. In <em>Salmonella</em> and <em>Escherichia coli</em>, curli fibers and phosphoethanolamine-cellulose are the major extracellular components of biofilms. The production of both is under the control of CsgD, a transcriptional regulator whose expression is modulated by a number of factors responding to different signals. The atypical MerR-like regulator MlrA is key in the activation of <em>csgD</em> transcription in both <em>Salmonella</em> and <em>E. coli</em>. Recently, MlrB, a SPI-2-encoded MlrA-like regulator that counteracts MlrA by repressing <em>csgD</em> transcription and biofilm formation inside macrophages was identified. Here, we characterize STM1266, a <em>Salmonella</em>-specific MlrA-like regulator, recently renamed BrfS. In contrast to <em>mlrA</em>, <em>brfS</em> transcription increases in minimal growth media and at 20 °C, a temperature not commonly tested in laboratories. Under these conditions, as well as in salt-limited rich medium, deletion or overexpression of <em>brfS</em> affects extracellular matrix production. Using transcriptomics, we uncovered genes under BrfS control relevant for biofilm formation such as <em>csgB</em> and <em>bapA</em>. Transcriptional analysis of these genes in mutants lacking <em>brfS</em>, <em>csgD</em> or both, indicates that BrfS controls curli biosynthesis both in a CsgD-dependent and independent manner. By contrast, at low temperatures, <em>bapA</em> transcription depends only on BrfS, and neither deletion of <em>csgD</em> nor of <em>mlrA</em> modify its expression. Based on these results, we propose that BrfS contributes to <em>Salmonella</em> persistence in the environment, where the pathogen encounters low temperatures and nutrient limitation.</div></div>","PeriodicalId":55844,"journal":{"name":"Biofilm","volume":"9 ","pages":"Article 100254"},"PeriodicalIF":5.9,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143100620","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development of a tri-species wound model for studying fungal-bacterial interactions and antimicrobial therapies","authors":"Stine Sørensen ,&nbsp;Lasse Kvich ,&nbsp;Yijuan Xu ,&nbsp;Trine R. Thomsen ,&nbsp;Thomas Bjarnsholt ,&nbsp;Ida Thaarup","doi":"10.1016/j.bioflm.2025.100256","DOIUrl":"10.1016/j.bioflm.2025.100256","url":null,"abstract":"<div><div>Chronic wounds are increasing in numbers and biofilm-producing bacteria are highly prevalent in these wounds and often create resilient polymicrobial infections. Moreover, estimates suggest that up to 23 % of wounds contain fungi, particularly <em>Candida albicans</em>. Currently, inter-kingdom chronic wound models are scarce; thus, this study presents one of the few <em>in vitro</em> models that incorporate both bacterial and fungal species in a wound-relevant environment, addressing a critical gap in current biofilm research. The newly developed model contained the commonly isolated wound bacteria <em>Pseudomonas aeruginosa</em> and <em>Staphylococcus aureus</em>, and the fungus <em>Candida albicans</em>. Inter-species interactions were investigated through selective plate counting and pH and oxygen measurements, as well as confocal microscopy. Investigations were carried out before and after exposure to commonly used clinical antimicrobial treatments, including silver-infused bandages. When grown in a tri-species consortium, <em>P. aeruginosa</em> and <em>S. aureus</em> exhibited a higher tolerance towards silver-infused bandages than when they were grown individually. This suggests that <em>C. albicans</em> plays a protective role for the bacteria. In addition, the treatment also caused a shift in species ratios, moving from a <em>P. aeruginosa</em>-dominated consortium to a <em>S. aureus</em>-dominated consortium. Moreover, confocal microscopy revealed a change in biofilm architecture when comparing single-species models to tri-species models. Finally, we observed that silver-infused bandages increased the pH in the tri-species model as well as partially restoring the oxygenation within the wound model. In conclusion, our novel model exemplifies how inter-kingdom interactions in fungal-bacterial infections can complicate both the microenvironment and treatment efficacy.</div></div>","PeriodicalId":55844,"journal":{"name":"Biofilm","volume":"9 ","pages":"Article 100256"},"PeriodicalIF":5.9,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143100579","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A novel MIR imaging approach for precise detection of S. epidermidis biofilms in seconds","authors":"Björn van Marwick ,&nbsp;Tatyana N. Sevastyanova ,&nbsp;Felix Wühler ,&nbsp;Barbara Schneider-Wald ,&nbsp;Cornelia Loy ,&nbsp;Sascha Gravius ,&nbsp;Matthias Rädle ,&nbsp;Andreas Schilder","doi":"10.1016/j.bioflm.2025.100270","DOIUrl":"10.1016/j.bioflm.2025.100270","url":null,"abstract":"<div><div>The impact of microbial biofilm growth poses a threat to both human health and the performance of industrial systems, manifesting as a global crisis with noteworthy economic implications for modern society. Exploring new methods and alternative approaches for the detection of biofilm signatures are imperative for developing optimized and cost-effective strategies that can help to identify early-stage biofilm formation. Clinical diagnostic technologies are constantly looking for more affordable, practical and faster methods of prevention and detection of chronic infections in periprosthetic joint infections (PJIs), which are often characterized by biofilm formation on implant surfaces. <em>Staphylococcus epidermidis (SE)</em> is especially known for its strong biofilm production and is considered a leading cause of biomaterial-associated infections, including PJIs. Implant-associated infections are severe and difficult to treat, therefore it is crucial to continue identifying bacterial biomarkers that contribute to its structural stability and attachment to implant surfaces. This study presents a pioneering approach for fast spectral detection of biofilm formation with a novel mid-infrared (MIR) scanning system. To highlight the advantages of our MIR system, we performed a comparative analysis with measurements from a commercially available Fourier-transform infrared (FTIR) scanner. We have assessed SE biofilms grown for 3 days comparing the processing times between a commercially available infrared (IR) scanning system (∼8 h/cm²), and our innovative scanning approach with rapid self-built MIR detection, achieving a reduction in scanning time to seconds. K-means clustering analysis identified pronounced differences in distribution of clusters, representing a significant variation between biofilm producing (RP62A) and non-biofilm producing (ATCC 12228) bacterial strains. The distribution serves as a critical tool for identifying biofilm phenotypes, particularly where poly-N-acetylglucosamine (PNAG), a key constituent of extracellular polymeric substances (EPS) in <em>S. epidermidis</em>, represents the dominant mass fraction in the samples analyzed by our infrared (IR) scanning systems. In addition to faster processing times, our novel MIR system demonstrated significantly higher sensitivity compared to FTIR, enabling clear differentiation between the chemical signatures of biofilm and planktonic strains. The corresponding novel approach integrates advanced data analytics with a newly designed rapid MIR prototype, enabling optimized and swift detection of biofilm signatures. These signatures, now recognized as critical targets in diagnosing complex infections, provide an alternative to traditional microbial detection methods in clinical diagnostics.</div></div>","PeriodicalId":55844,"journal":{"name":"Biofilm","volume":"9 ","pages":"Article 100270"},"PeriodicalIF":5.9,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143577743","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Diverse reactions of aquaculture biofilter biofilms following acute high-dose peracetic acid","authors":"Wanhe Qi ,&nbsp;Sanni L. Aalto ,&nbsp;Peter Vilhelm Skov ,&nbsp;Kim João de Jesus Gregersen ,&nbsp;Lars-Flemming Pedersen","doi":"10.1016/j.bioflm.2025.100277","DOIUrl":"10.1016/j.bioflm.2025.100277","url":null,"abstract":"<div><div>Peracetic acid (PAA) is an effective disinfectant in aquaculture systems to reduce pathogen loads and improve water quality. However, its effectiveness in disinfecting biofilm in recirculating aquaculture systems (RAS) and resetting biofilters between productions remains unknown. This study evaluated the effects of acute PAA exposure on biofilter biofilms from freshwater RAS. Identical types of bioelements were collected from a pilot-scale RAS (without prior PAA treatment) and a commercial RAS (with PAA treatment), and exposed to PAA concentrations of 0, 1, 2, 4, 8, and 16 mg/L for 1 h. Microbial activity and viability of the exposed biofilms were evaluated using respirometry and flow cytometry. Results showed dose-dependent inhibition of biofilm activity and viability in the pilot-scale RAS. Nitrite oxidation was the most sensitive process to PAA, with an IC₅₀ of 1.27 mg/L (the concentration at which PAA inhibited biofilm metabolic activity by 50 %), followed by ammonia oxidation (IC₅₀ = 1.59 mg/L) and endogenous respiration (IC₅₀ = 2.67 mg/L). Microbial activity linked to H₂O₂ decomposition was least affected (IC₅₀ = 4.68 mg/L). Live cell counts decreased from 9.1 × 10⁷ counts/cm² to 2.4 × 10⁷ counts/cm² of bioelement surface, with dead cells proportion increasing from 15 % to 54 %. In contrast, biofilter biofilms from the commercial RAS exhibited significantly lower sensitivity to PAA dosage, with reductions in nitrite oxidation (39 %) and ammonia oxidation (51 %) observed only at 16 mg/L compared to control. These findings suggest that routine PAA exposure, as part of the other operating conditions on the commercial RAS, can enhance the biofilm's sensitivity to PAA. The study provides new insight into the sensitivity of aquaculture biofilm to PAA treatment and its effect on associated microbial processes.</div></div>","PeriodicalId":55844,"journal":{"name":"Biofilm","volume":"9 ","pages":"Article 100277"},"PeriodicalIF":5.9,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143783589","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"In vivo efficacy of a refillable intrawound drug delivery device in a sheep model of biofilm-compromised open fracture-related infection","authors":"Dustin Williams ,&nbsp;David Rothberg ,&nbsp;Walker Kay ,&nbsp;Lisa Nehring ,&nbsp;Robert Falconer ,&nbsp;Richard Tyler Epperson ,&nbsp;Brooke Kawaguchi ,&nbsp;Carolyn Ardizzone ,&nbsp;Brian Barnum ,&nbsp;Nicholas Ashton","doi":"10.1016/j.bioflm.2025.100262","DOIUrl":"10.1016/j.bioflm.2025.100262","url":null,"abstract":"<div><div>Open fracture-related infection challenges persist in healthcare. From the time open fractures were defined ∼50 years ago, infection rates have gone essentially unchanged. Contributing factors include compromised vasculature, biofilm, and stalled innovations in treatment and prophylaxis. In this study, we engineered and tested the efficacy of a refillable drug delivery device, the Purgo Pouch (Pouch), that sustains local, high dose intrawound antibiotic concentrations in wound sites. We hypothesized that it would manage biofilm-compromised open fracture-related infection better than clinical standards of care. Therapies were tested in a unique sheep model of long bone open fracture-related infection with compromised tissue and biofilm inocula of methicillin-resistant <em>Staphylococcus aureus</em>. Sheep (n = 5/group) were treated with IV vancomycin (10 days), gentamicin-loaded CaSO₄ beads (single application), or the Pouch (10 days) loaded with gentamicin alone or a triple antibiotic combination. At 21 days, sheep were euthanized and microbiological and histological data collected. Results indicated that the Pouch managed infection more effectively, reducing bioburden to &lt;10⁵ colony forming units (CFU)/sample, which was statistically significant compared to clinical standards, which failed to reduce bioburden to below 10⁵ CFU. The hypothesis was supported. The Pouch received Breakthrough Device Designation by the FDA, is being transitioned toward clinical trials, and is a potential solution to the long-standing problem of open fracture-related infection.</div></div>","PeriodicalId":55844,"journal":{"name":"Biofilm","volume":"9 ","pages":"Article 100262"},"PeriodicalIF":5.9,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143453999","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Harnessing emergent properties of microbial consortia for Agriculture: Assembly of the Xilonen SynCom","authors":"Gabriela Gastélum ,&nbsp;Bruno Gómez-Gil ,&nbsp;Gabriela Olmedo-Álvarez ,&nbsp;Jorge Rocha","doi":"10.1016/j.bioflm.2025.100284","DOIUrl":"10.1016/j.bioflm.2025.100284","url":null,"abstract":"<div><div>Synthetic communities (SynComs) are valuable tools for addressing microbial community assembly and function, towards their manipulation for clinical, biotechnological and agricultural applications. However, SynCom design is complicated since interactions between microbes cannot be predicted based on their individual properties. Here we aimed to assemble a functionally cohesive SynCom displaying high-order interactions, as a model to study the community-level beneficial functions of seed-endophytic bacteria from native maize landraces<em>,</em> including strains from the Bacilli class, and the <em>Burkholderia</em> and <em>Pseudomonas</em> genera. We developed a partial combinatorial, bottom-up strategy that was followed by the detection of complex colony architecture as an emergent property in co-cultures. Using this simplified approach, we tested less than 400 co-cultures from a pool of 27 strains, resulting in the assembly the <em>Xilonen</em> SynCom, which includes <em>Bacillus pumilus</em> NME155, <em>Burkholderia contaminans</em> XM7 and <em>Pseudomonas</em> sp. GW6. In this community, higher-order interactions result in complex colony architecture, which is considered a proxy of biofilm formation. Additionally, we generated protocols for absolute quantification of each member from a complex mixture. The <em>Xilonen</em> SynCom will serve as a model to study biofilm formation in community settings, and will aid in the study of the molecular and ecological basis mediating maize fertility.</div></div>","PeriodicalId":55844,"journal":{"name":"Biofilm","volume":"9 ","pages":"Article 100284"},"PeriodicalIF":5.9,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143907643","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Proteomic signatures of Staphylococcus aureus biofilm maturation on orthopaedic implants","authors":"C. Kuik ,&nbsp;C. de Boer ,&nbsp;S.W.G. van Hoogstraten ,&nbsp;K. Freulings ,&nbsp;M. Honing ,&nbsp;J.J.C. Arts ,&nbsp;B. Cillero-Pastor","doi":"10.1016/j.bioflm.2025.100287","DOIUrl":"10.1016/j.bioflm.2025.100287","url":null,"abstract":"<div><div>Implant-associated infections pose a significant clinical challenge in the orthopaedic field, often leading to implant failure and revision surgeries. These infections are hard to treat, particularly due to the formation of bacterial biofilms. Orthopaedic implant surfaces feature varying roughness and compositions to optimise implant osseointegration and performance. Highly polished surfaces are used in articulating areas of high shear force to minimise wear particle formation, while rough or porous surfaces enhance implant and bone fixation. However, increased surface roughness or porosity can also promote bacterial adhesion and biofilm formation, potentially elevating the risk of chronic infections. In this study, an automated single-pot solid-phase enhanced sample preparation protocol (SP3) workflow was developed to investigate the differences in proteomic response of immature and mature <em>S. aureus</em> biofilms on titanium (Ti) surfaces with varying roughness (polished, corundum-blasted), and a plasma-sprayed microporous calcium phosphate coated surface (plasmapore), representing clinically relevant orthopaedic implants. Mature biofilms showed increased proteins related to toxin activity and the tricarboxylic acid (TCA) cycle, while immature biofilms had elevated proteins tied to binding, catalytic activities, and metabolism, suggesting surface topography influences early biofilm formation. This study highlights potential protein targets for novel antimicrobial therapies and suggests testing these as coatings on Ti surfaces, with the proteomics platform serving as a tool to evaluate bacterial and host responses.</div></div>","PeriodicalId":55844,"journal":{"name":"Biofilm","volume":"9 ","pages":"Article 100287"},"PeriodicalIF":5.9,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144190518","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Early fibrin biofilm development in cardiovascular infections","authors":"Safae Oukrich ,&nbsp;Jane Hong ,&nbsp;Mariël Leon-Grooters ,&nbsp;Wiggert A. van Cappellen ,&nbsp;Johan A. Slotman ,&nbsp;Gijsje H. Koenderink ,&nbsp;Willem J.B. van Wamel ,&nbsp;Moniek P.M. de Maat ,&nbsp;Klazina Kooiman ,&nbsp;Kirby R. Lattwein","doi":"10.1016/j.bioflm.2025.100261","DOIUrl":"10.1016/j.bioflm.2025.100261","url":null,"abstract":"<div><div>The single most common microbe causing cardiovascular infections is <em>Staphylococcus aureus</em> (<em>S. aureus</em>). <em>S. aureus</em> produces coagulase that converts fibrinogen to fibrin, which is incorporated into biofilms. This process aids in adherence to intravascular structures, defense against the host immune system, and resistance to antimicrobial treatment. Despite its significance, fibrin formation in <em>S. aureus</em> biofilms remains poorly understood. Therefore, this study aimed to elucidate the early development of cardiovascular biofilms. Clinically isolated coagulase-positive <em>S. aureus</em> and coagulase-negative <em>Staphylococcus lugdunensis</em> (<em>S. lugdunensis</em>) from patients with cardiovascular infections, and a coagulase mutant <em>S. aureus</em> Δcoa, were grown in tryptic soy broth (TSB), Iscove's Modified Dulbecco's Medium (IMDM), and pooled human plasma, with or without porcine heart valves. Bacterial growth, metabolic activity, and bacterial fibrinogen utilization were measured over 24 h at 37 °C. Time-lapse confocal microscopy was used to visualize and track biofilm development. <em>S. aureus</em> exhibited more growth in TSB and human plasma than <em>S. lugdunensis</em> and <em>S. aureus</em> Δcoa, but showed similar growth in IMDM after 24 h. Peak metabolic activity for all isolates was highest in TSB and lowest in human plasma. The presence of porcine valves caused strain-dependent alterations in time to peak metabolic activity. Confocal imaging revealed fibrin-based biofilm development exclusively in the coagulase-producing <em>S. aureus</em> strains. Between 2 and 6 h of biofilm development, 74.9 % (p = 0.034) of the fibrinogen from the medium was converted to fibrin. Variations in fibrin network porosity and density were observed among different coagulase-producing <em>S. aureus</em> strains. Fibrin formation is mediated by <em>S. aureus</em> coagulase and first strands occurred within 3 h for clinical strains after exposure to human plasma. This study stresses the importance of experimental design given the bacterial changes due to different media and substrates and provides insights into the early pathogenesis of <em>S. aureus</em> cardiovascular biofilms.</div></div>","PeriodicalId":55844,"journal":{"name":"Biofilm","volume":"9 ","pages":"Article 100261"},"PeriodicalIF":5.9,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143419270","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Examining the impact of probiotic Lactiplantibacillus pentosus 6MMI on inhibiting biofilm formation, adhesion, and virulence gene expression in Listeria monocytogenes ATCC 19115","authors":"Behrooz Alizadeh Behbahani ,&nbsp;Mostafa Rahmati-Joneidabad ,&nbsp;Morteza Taki","doi":"10.1016/j.bioflm.2025.100255","DOIUrl":"10.1016/j.bioflm.2025.100255","url":null,"abstract":"<div><div>Probiotic bacteria improve human health by secreting pro-microbial substances, balancing intestinal flora, binding to the mucous membrane and epithelium, strengthening the intestinal epithelial barrier, and creating interactions between the gastrointestinal microbiota and the immune system. This study aimed to investigate the probiotic potential, biofilm-related gene expression and anti-biofilm capabilities of <em>Lactiplantibacillus pentosus</em> 6MMI. The strain exhibited remarkable resilience to challenging conditions, including acidic environments, gastrointestinal settings, and bile salts. Notably, <em>Lpb. pentosus</em> demonstrated significant hydrophobicity (71.89 %), auto-aggregation (42.39 %), co-aggregation (51.28 %), antioxidant activity (ranging from 42.29 % to 64.61 %), and a cholesterol reduction capacity of 50.31 %. Its competitive abilities against <em>Listeria monocytogenes</em> were quantified, showing a competition rate of 54.51 %, displacement rate of 48.57 %, and inhibition of adhesion at 27.71 %. Also, <em>Lpb. pentosus</em> resulted an adhesion rate of 12.91 % to epithelial cells and showed no DNase or hemolytic activity. The strain exhibited the highest resistance to nalidixic acid, with an inhibition zone measuring 15.20 mm, while it was least resistant to chloramphenicol, which had an inhibition zone of 27.30 mm. Treatment with cell-free supernatant (CFS) from <em>Lpb. pentosus</em> significantly reduced biofilm formation by 91.25 % and 24.50 % and diminished mature biofilm formation by 83.82 % and 21.80 % on <em>L. monocytogenes</em>. Additionally, the CFS inhibited the transcription of the <em>plcB</em>, <em>hly</em>, and <em>prfA</em> genes in <em>L. monocytogenes</em>, suggesting a potential reduction in bacterial virulence through decreased hemolysin release and modulation of phospholipase activity. In the next step of the study, the Gaussian Process Regression (GPR) model accurately predicted bile tolerance and acid parameters with a high R² of 0.99 and minimal Mean Absolute Percentage Error (MAPE) values of 0.33 % and 0.21 %, respectively. The residual errors showed a normal distribution, indicating reliable and consistent predictions. Overall, <em>Lpb. pentosus</em> 6MMI represents a valuable candidate for further investigation in probiotic development and biofilm management strategies.</div></div>","PeriodicalId":55844,"journal":{"name":"Biofilm","volume":"9 ","pages":"Article 100255"},"PeriodicalIF":5.9,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143100578","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}