AnaerobePub Date : 2025-10-01Epub Date: 2025-07-25DOI: 10.1016/j.anaerobe.2025.102987
Jessica M Chisholm, Charlotte Bell, Molly Lattin, Su Chen Lim, Simon A Reid, Linda A Selvey, Thomas V Riley
{"title":"High prevalence of Clostridioides difficile in retail garden products from two Australian states.","authors":"Jessica M Chisholm, Charlotte Bell, Molly Lattin, Su Chen Lim, Simon A Reid, Linda A Selvey, Thomas V Riley","doi":"10.1016/j.anaerobe.2025.102987","DOIUrl":"10.1016/j.anaerobe.2025.102987","url":null,"abstract":"<p><strong>Background: </strong>Despite historically being considered a healthcare-associated pathogen, rates of Clostridioides difficile infection in the community have risen greatly in recent decades. As a pathogen of One Health importance, sources of C. difficile in the community have been sought to understand and control community-associated C. difficile infection transmission.</p><p><strong>Objectives: </strong>This study aimed to investigate the prevalence and molecular characteristics of C. difficile isolated from retail garden products in two Australian states.</p><p><strong>Methods: </strong>Soil conditioners, soil mixes and turf samples were collected from commercial garden product suppliers in Western Australia and Queensland from May 2023 to January 2024. Following enrichment culture, PCR ribotyping and toxin gene profiling were performed on C. difficile isolates.</p><p><strong>Results: </strong>C. difficile was recovered from 257 of 479 (53.7 %) retail garden products in this study. Prevalence was highest in turf (67.1 %, 53/79), followed by soil mixes (57.1 %, 148/259) and soil conditioners (39.7 %, 56/141). Of the 113 distinct ribotypes identified, the most common were 014/020 and QX 686. Toxigenic ribotypes associated with both human infection and production animals in Australia, including 014/020, 056 and 087, were recovered.</p><p><strong>Conclusion: </strong>A high prevalence of C. difficile was found in garden products sold to consumers, including toxigenic strains associated with C. difficile infection in humans and animals. More discriminatory characterisation of isolates is required to determine if retail garden products contribute to the burden of community-associated C. difficile infection in Australia.</p>","PeriodicalId":8050,"journal":{"name":"Anaerobe","volume":" ","pages":"102987"},"PeriodicalIF":2.6,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144726869","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
AnaerobePub Date : 2025-10-01Epub Date: 2025-07-17DOI: 10.1016/j.anaerobe.2025.102985
Zhenghui Li, Ashlesh K Murthy, C Hal Jones, Kwok Lee, Urvi Rajyaguru, Deepika Athinarayanan, Lubomira Andrew, Richard V Goering, Shuhei Ito, Elisa Gonzalez, Pingping Zhang, Paul A Liberator, Warren V Kalina, Michael W Pride, Frederick J Angulo, Jennifer C Moïsi, Kazuhiro Tateda
{"title":"Molecular characterization of Clostridioides difficile isolated from older adults during prospective population-based active surveillance at nine hospitals in Tokyo, Japan, 2018-2020.","authors":"Zhenghui Li, Ashlesh K Murthy, C Hal Jones, Kwok Lee, Urvi Rajyaguru, Deepika Athinarayanan, Lubomira Andrew, Richard V Goering, Shuhei Ito, Elisa Gonzalez, Pingping Zhang, Paul A Liberator, Warren V Kalina, Michael W Pride, Frederick J Angulo, Jennifer C Moïsi, Kazuhiro Tateda","doi":"10.1016/j.anaerobe.2025.102985","DOIUrl":"10.1016/j.anaerobe.2025.102985","url":null,"abstract":"<p><strong>Background: </strong>To characterize Clostridioides difficile isolates identified during a prospective multi-hospital population-based study of C. difficile infection (CDI).</p><p><strong>Methods: </strong>Between December 2018 and March 2020, inpatients ≥50 years of age with new-onset diarrhea in nine Tokyo hospitals were investigated for CDI. Stool specimens were screened by C. DIFF QUIK CHEK COMPLETE® and glutamate dehydrogenase (GDH) positive stools tested by Xpert® C. difficile/Epi PCR assay. PCR positive stools were tested by cytotoxicity neutralization assay to determine presence of functional toxin. GDH positive stools were also anaerobically cultured and whole genome sequences of C. difficile isolates were acquired.</p><p><strong>Results: </strong>Toxigenic C. difficile were isolated from 64 patients with CDI; 22 were RT018/356, 9 were RT369, 4 each were RT106 and RT002, 15 were other RTs, and 10 had an unknown RT. Four isolates were positive for binary toxin: one isolate each of RT027, RT078/126, RT080, and one unknown. In terms of the pathogenicity locus profile, 55 were tcdA+/tcdB+ and 9 were tcdA-/tcdB+. In terms of ST, 23 were ST17, nine were ST81, 31 were other STs, and one had a novel ST.</p><p><strong>Conclusions: </strong>Consistent with prior studies, C. difficile isolates from patients with CDI represented diverse ribotypes with approximately one third of isolates RT018/356. Of note, one isolate each of RT027 and RT078/126 were identified, indicating these hypervirulent strains are present in hospitals in Japan. Public health interventions are needed to reduce the CDI burden in Japan.</p>","PeriodicalId":8050,"journal":{"name":"Anaerobe","volume":" ","pages":"102985"},"PeriodicalIF":2.6,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144666880","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Taxonomy for clinicians - recent changes in names of anaerobic species with pathogenic or probiotic properties.","authors":"Lyudmila Boyanova, Raina Gergova, Rumyana Markovska","doi":"10.1016/j.anaerobe.2025.103002","DOIUrl":"https://doi.org/10.1016/j.anaerobe.2025.103002","url":null,"abstract":"","PeriodicalId":8050,"journal":{"name":"Anaerobe","volume":" ","pages":"103002"},"PeriodicalIF":2.6,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145211442","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
AnaerobePub Date : 2025-09-30DOI: 10.1016/j.anaerobe.2025.103003
L Ruffier d'Epenoux, E Fayoux, K Rwayane, C Hervochon, S Corvec
{"title":"Advances in understanding Cutibacterium acnes hemolysis: virulence factor or genomic trait?","authors":"L Ruffier d'Epenoux, E Fayoux, K Rwayane, C Hervochon, S Corvec","doi":"10.1016/j.anaerobe.2025.103003","DOIUrl":"https://doi.org/10.1016/j.anaerobe.2025.103003","url":null,"abstract":"<p><strong>Background: </strong>Cutibacterium acnes is now recognized a major opportunistic pathogen causing a wide range of infections. Henceforth, this bacterium is largely involved in device-related infections especially prosthetic joint infections, spine infections but also cardiovascular infections, neurosurgical implant infections and breast infections. It has also been associated with acne and probably sarcoidosis and prostate tumors. We conducted a narrative review to better understand the phylotypes involved in this clinical entities and if hemolysis can be a diagnosis maker of pathogenicity.</p><p><strong>Methods: </strong>We searched the PubMed database for English language articles related to C. acnes phylotype and clinical entities and hemolysin characteristic.</p><p><strong>Results: </strong>As a successful commensal microorganism, C. acnes produces many virulence factors including cytolysins that most likely facilitate tissue damages due to its β-hemolytic trait. In this review, we summarize its involvement in different clinical settings and the role of this virulence factor depending on the phylotype implicated. Our analysis of the literature on C. acnes β-hemolysis clinical strains sheds new light on its potential impact in distinguishing C. acnes infection strains from contaminant strains.</p><p><strong>Conclusion: </strong>The litterature and our results demonstrate the genetic nature of the β-hemolysis in C. acnes strains rather than being a mean to differentiate virulent clinical strains from commensal or other strains.</p>","PeriodicalId":8050,"journal":{"name":"Anaerobe","volume":" ","pages":"103003"},"PeriodicalIF":2.6,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145211394","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Lipoproteins from Bilophila wadsworthia cell wall induce innate immune responses through Toll-like receptor 2","authors":"Chika Yoshida , Mao Hagihara , Reina Azuma , Kenta Iwasaki , Akiko Nakamura , Hiroyuki Suematsu , Kaori Tanaka , Tadashi Ariyoshi , Kentaro Oka , Motomichi Takahashi , Yuka Yamagishi , Hiroshige Mikamo","doi":"10.1016/j.anaerobe.2025.103001","DOIUrl":"10.1016/j.anaerobe.2025.103001","url":null,"abstract":"<div><h3>Objectives</h3><div><em>Bilophila wadsworthia</em> is a commensal gram-negative anaerobic bacterium in the human gut that is often isolated from patients diagnosed with appendicitis and inflammatory bowel disease. Although previous studies have indicated that <em>B. wadsworthia</em> can cause and/or exacerbate inflammatory diseases, the precise underlying mechanism remains unclear. In the present study, we explored the inflammation-causing virulence factors of <em>B. wadsworthia</em>.</div></div><div><h3>Methods</h3><div>To identify the virulence factors of <em>B. wadsworthia</em>, we investigated the whole-genome sequences of 25 <em>B. wadsworthia</em> isolates. We then used the publicly available virulence factor database (VFDB) to search for virulence factor genes. We also conducted in vitro and in vivo studies to determine the importance of the selected virulence factors causing inflammation.</div></div><div><h3>Results</h3><div><em>Bilophila wadsworthia</em> isolates have 30 common virulence factor genes that contribute to inflammation, invasion of the human body, and effector delivery system. These genes were associated with lipopolysaccharide, capsules, and membrane-associated proteins. Among them, lipoproteins, sometimes act as components of transporter proteins in the bacterial cell wall, upregulated the expression of tumor necrosis factor in murine spleen cells. However, the effect of lipoproteins was attenuated by a Toll-like receptor 2 antagonist. Additionally, orally administered <em>B. wadsworthia</em> and <em>B. wadsworthia</em>-produced lipoproteins worsened colitis <em>in vivo</em>.</div></div><div><h3>Conclusions</h3><div><em>Bilophila wadsworthia</em> contains genes that encode various virulence factors. Among these, lipoproteins produced by <em>B. wadsworthia</em> can act as inflammation-inducing factors via Toll-like receptor 2.</div></div>","PeriodicalId":8050,"journal":{"name":"Anaerobe","volume":"96 ","pages":"Article 103001"},"PeriodicalIF":2.6,"publicationDate":"2025-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145190742","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
AnaerobePub Date : 2025-09-24DOI: 10.1016/j.anaerobe.2025.103000
Deirdre A. Collins , Su Chen Lim , Jessica Chisholm , Molly Lattin , Linda Selvey , Simon Reid , Thomas V. Riley
{"title":"Prevalence and molecular types of Clostridioides (Clostridium) difficile on Australian retail vegetables and household surfaces","authors":"Deirdre A. Collins , Su Chen Lim , Jessica Chisholm , Molly Lattin , Linda Selvey , Simon Reid , Thomas V. Riley","doi":"10.1016/j.anaerobe.2025.103000","DOIUrl":"10.1016/j.anaerobe.2025.103000","url":null,"abstract":"<div><h3>Objectives</h3><div>Community-onset <em>Clostridioides</em> (<em>Clostridium</em>) <em>difficile</em> infection (CDI) has risen to >80 % of all CDI cases in Australia. High prevalence of <em>C. difficile</em> contamination has been reported in many community sources including retail root vegetables. Household surfaces may become contaminated with <em>C. difficile</em> when storing and handling contaminated vegetables. This study aimed to determine the prevalence and molecular types of <em>C. difficile</em> present on retail root vegetables and household surfaces.</div></div><div><h3>Methods</h3><div>From April 2023 to March 2024, retail potatoes (n = 255) and onions (n = 305) were sampled at 3-monthly intervals. Environmental samples were collected from homes of householders in Queensland (n = 105) and Western Australia (n = 124) who regularly purchased unwashed potatoes. Swabs were collected from their countertop/chopping board, vegetable storage area and an unwashed potato. Pooled potato peels, pooled onion roots and household swab samples underwent enrichment culture for <em>C. difficile</em>. <em>C. difficile</em> isolates were characterized by PCR ribotyping and detection of toxin genes.</div></div><div><h3>Results</h3><div><em>C. difficile</em> was cultured from 5.6 % of all 679 household samples, 35.3 % of 255 retail potato samples and 20.3 % of retail onion 305 samples. At least one environmental/potato sample was positive for 15.7 % of all 229 households. Among 84 <em>C. difficile</em> ribotypes (RTs), 056, 286, 101 and 125 predominated on vegetables in Western Australia and RTs 101, QX 098, 014/020 and QX 601 were most common on Queensland vegetables.</div></div><div><h3>Conclusions</h3><div>Toxigenic strains of <em>C. difficile</em> were identified on retail vegetables and within households, highlighting potential for CDI to be acquired within households. Populations at high risk of CDI e.g. patients with inflammatory bowel disease or cancer, could benefit from education on safe handling and cleaning of potential sources of <em>C. difficile</em> in their homes.</div></div>","PeriodicalId":8050,"journal":{"name":"Anaerobe","volume":"96 ","pages":"Article 103000"},"PeriodicalIF":2.6,"publicationDate":"2025-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145172714","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Effects of common cosmetic ingredients on growth of dominant human skin inhabitant Cutibacterium acnes","authors":"Osamu Funatsu , Itaru Dekio , Hiroko Ishii , Reiko Shimatsu , Yutaka Shimokawa , Akihiko Asahina","doi":"10.1016/j.anaerobe.2025.102999","DOIUrl":"10.1016/j.anaerobe.2025.102999","url":null,"abstract":"<div><h3>Objectives</h3><div>Cosmetic products, which typically contain multiple ingredients such as ethanol, glycerol and Tween 80 (polysorbate 80), may influence the homeostasis of the skin microbiome. However, the effect of common ingredients on the anaerobic members of human skin microbiome is poorly studied. In this study, we directly evaluated the effects of common cosmetic ingredients on a dominant human skin anaerobe <em>Cutibacterium acnes</em> using <em>in vitro</em> techniques.</div></div><div><h3>Materials and methods</h3><div>Five cosmetic ingredients were added to seven <em>C</em>. <em>acnes</em> strains, including type strains of the three subspecies (types I, II, and III), and their effects were evaluated by monitoring growth curves based on turbidity measurements.</div></div><div><h3>Results</h3><div>All strains exhibited growth inhibition in response to high concentrations (10 % v/v) of ethanol and glycerol, whereas low concentrations (3 % and/or 1 % v/v) of ethanol enhanced bacterial growth. The nonionic detergent Tween 80 significantly enhanced the growth of type I strains, with some strains also producing insoluble precipitates, which may relate to comedogenesis. In contrast, type III strains did not produce precipitates. The two polyamines, putrescine and spermidine, elicited a biphasic response, with growth inhibition observed at higher concentrations and growth promotion at lower concentrations.</div></div><div><h3>Conclusion</h3><div>The response of <em>C. acnes</em> subspecies/strains to the cosmetic components varied with the different ingredient concentrations, often exhibiting opposite effects.</div></div>","PeriodicalId":8050,"journal":{"name":"Anaerobe","volume":"96 ","pages":"Article 102999"},"PeriodicalIF":2.6,"publicationDate":"2025-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145147570","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
AnaerobePub Date : 2025-09-18DOI: 10.1016/j.anaerobe.2025.102997
Charlie Zins , Loic Biere , Mohamed Braham , Rachel Chenouard , Matthieu Eveillard , Marie Kempf , Vincent Dubée , Hélène Pailhoriès
{"title":"Finegoldia magna, a neglected cause of endocarditis – case report","authors":"Charlie Zins , Loic Biere , Mohamed Braham , Rachel Chenouard , Matthieu Eveillard , Marie Kempf , Vincent Dubée , Hélène Pailhoriès","doi":"10.1016/j.anaerobe.2025.102997","DOIUrl":"10.1016/j.anaerobe.2025.102997","url":null,"abstract":"<div><div><em>Finegoldia magna</em> endocarditis is a rare and underdiagnosed condition, primarily affecting prosthetic valves. We report a case, along with a comprehensive literature review, highlighting its subacute presentation and the challenges in diagnosis due to frequent negative blood cultures. Molecular detection methods and prolonged delay for anaerobic cultures are crucial for identifying <em>F. magna</em>. Given the high risk of significant valvular damage, including abscess formation, surgical intervention might be required. Antibiotic treatments in the literature include penicillins, with or without metronidazole. Clinicians should consider this underestimated pathogen as a potential cause of early prosthetic valve endocarditis, particularly in cases of sterile blood cultures.</div></div>","PeriodicalId":8050,"journal":{"name":"Anaerobe","volume":"96 ","pages":"Article 102997"},"PeriodicalIF":2.6,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145097791","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
AnaerobePub Date : 2025-09-17DOI: 10.1016/j.anaerobe.2025.102998
Inga-Maria Frick, Ariane Neumann
{"title":"Binding to Thrive: Decoding Atopobium spp. Interactions with Host Proteins and Immune Cells.","authors":"Inga-Maria Frick, Ariane Neumann","doi":"10.1016/j.anaerobe.2025.102998","DOIUrl":"https://doi.org/10.1016/j.anaerobe.2025.102998","url":null,"abstract":"<p><strong>Objectives: </strong>Gram-positive anaerobic cocci are opportunistic pathogens that exploit immune suppression or tissue injury to establish infections. Atopobium spp. are clinically relevant, being linked to bacterial vaginosis, abdominal wounds, pelvic abscesses, and dental infections. While clinical reports describe the involvement in detrimental host conditions, in-depth knowledge is missing to understand how these bacteria acquire essential nutrients to evade immune responses and directly interact with the human host.</p><p><strong>Methods: </strong>Here we analyzed the growth of three blood-isolated Atopobium strains in different media and compared them to Finegoldia magna. Using radioactive binding studies, human serum albumin (HSA), a major component of serum, was identified as the primary binding partner, subsequently facilitating bacterial growth by providing essential nutrients. Next, we investigated the ability of Atopobium to interact with human blood-isolated neutrophils.</p><p><strong>Results: </strong>Interestingly, Atopobium triggered neutrophil activation, detected by increased reactive oxygen species (ROS) production, secretion of the sepsis marker heparin-binding protein (HBP), and the induction of extracellular trap (NET) formation.</p><p><strong>Conclusions: </strong>These findings provide new insights into how Atopobium utilizes host serum components and facilitates host interactions, highlighting their potential role in immune modulation and pathogenesis.</p>","PeriodicalId":8050,"journal":{"name":"Anaerobe","volume":" ","pages":"102998"},"PeriodicalIF":2.6,"publicationDate":"2025-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145090897","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
AnaerobePub Date : 2025-09-12DOI: 10.1016/j.anaerobe.2025.102996
Camila Fonseca Rizek , Marina Farrel Côrtes , Bianca Helena Ventura Fernandes , Silvia Figueiredo Costa , Evelyne Santana Girão , Roberta Cristina Martins , Sânia Alves dos Santos , Bruno de Melo Tavares , Luciani Silveira de Carvalho , Cecilia Leite Costa , Daniely Viana Costa , Geovania Maciel , Gerly Anne de Castro Brito , Lauro Vieira Perdigão Neto
{"title":"Zebrafish as an in vivo model to study the pathogenicity of Clostridioides difficile clinical strains","authors":"Camila Fonseca Rizek , Marina Farrel Côrtes , Bianca Helena Ventura Fernandes , Silvia Figueiredo Costa , Evelyne Santana Girão , Roberta Cristina Martins , Sânia Alves dos Santos , Bruno de Melo Tavares , Luciani Silveira de Carvalho , Cecilia Leite Costa , Daniely Viana Costa , Geovania Maciel , Gerly Anne de Castro Brito , Lauro Vieira Perdigão Neto","doi":"10.1016/j.anaerobe.2025.102996","DOIUrl":"10.1016/j.anaerobe.2025.102996","url":null,"abstract":"<div><h3>Objectives</h3><div><em>Clostridioides difficile</em> is a major cause of nosocomial diarrhea, and its virulence is typically attributed to the production of toxins. However, other genomic factors may contribute to its pathogenicity. To study the <em>in vivo</em> aspects of <em>C. difficile</em> infection, various animal models have been employed. Zebrafish (<em>Danio rerio</em>) offers several advantages over mammalian models, but there are still few studies using it to evaluate <em>C. difficile</em> infection. Here, we aimed to explore <em>in vivo</em> virulence differences among clinical strains by employing the zebrafish embryo model using eight sequenced <em>C. difficile</em> isolates with distinct genomic profiles.</div></div><div><h3>Methods</h3><div>Embryos were microinjected with bacterial suspensions, and mortality and cardiac edema were monitored over 96 h. Survival and cardiotoxicity were assessed and correlated with whole-genome data and clinical outcomes.</div></div><div><h3>Results</h3><div>Two strains exhibited distinct pathogenic effects: HC48 (ST42) caused significantly increased mortality (p < 0.0001), and HC132 (ST669) induced cardiotoxicity in 20 % of embryos. Surprisingly, the hypervirulent control strain NAP1/027 did not produce enhanced virulence in this model.</div></div><div><h3>Conclusion</h3><div>While zebrafish embryos showed promise for distinguishing strain-specific virulence, limitations such as colonization capacity and host–microbe interactions suggest that further research is needed to validate this model for <em>C. difficile</em> virulence testing.</div></div>","PeriodicalId":8050,"journal":{"name":"Anaerobe","volume":"96 ","pages":"Article 102996"},"PeriodicalIF":2.6,"publicationDate":"2025-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145063283","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}