Anaerobe最新文献

{"title":"Chitin promotes equol production via n-acetylglucosamine in human fecal cultures.","authors":"Miyuki Kodera, Kohei Nakamura, S Yokoyama","doi":"10.1016/j.anaerobe.2024.102923","DOIUrl":"10.1016/j.anaerobe.2024.102923","url":null,"abstract":"<p><strong>Objectives: </strong>Equol is a metabolite of isoflavone. Here, we investigated the effect of dietary fiber on equol-producing microbiota.</p><p><strong>Methods: </strong>Human feces was anaerobically cultured in Gifu Anaerobic Medium (GAM) containing 1 mg/L daidzein supplemented with 1 % (w/v) dietary fiber (pectin, chitin, or resistant starch [RS]). The equol conversion rate, number of equol-producing bacteria, pH, short-chain fatty acids (SCFAs), and microbial composition were measured in fecal cultures.</p><p><strong>Results: </strong>Equol conversion significantly increased by 2.7-fold in the chitin group compared with the control group. Conversely, the conversion rate decreased to one-tenth in the pectin group and one-third in the RS group. The number of equol-producing bacteria also significantly increased in the chitin group compared with the control group. Whereas pH values and acetate/propionate concentrations decreased in the pectin and RS groups compared with the control group, no significant differences were observed in the chitin group. Microbiota analysis indicated that the relative abundances of Bifidobacterium and Lactobacillus increased, whereas those of Dorea, Lachnoclostridium, and Eggerthella decreased in the pectin and RS groups. In contrast, these abundances remained stable in the chitin group. The relative abundances of Adlercreutzia and Slackia remained unchanged across all groups. In vitro cultures of Eggerthella sp. strain YY7918 and Adlercreutzia equolifaicens JCM14793 demonstrated that equol conversion from daidzein was stimulated by the addition of 0.5-1% (w/v) n-acetylglucosamine, a breakdown product of chitin, but not chitin itself.</p><p><strong>Conclusions: </strong>Our findings suggest that equol production is stimulated by n-acetylglucosamine, derived from decomposed chitin, in certain equol-producing bacteria without affecting their growth.</p>","PeriodicalId":8050,"journal":{"name":"Anaerobe","volume":" ","pages":"102923"},"PeriodicalIF":2.5,"publicationDate":"2024-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142738151","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":"Veillonella orientalis sp. nov., an anaerobic Gram-stain-negaitve coccus isolated from saliva of a Thai child.","authors":"Izumi Mashima-Usami, Citra F Theodorea, Kiyoshi Murata, Boonyanit Thaweboon, Sroisiri Thaweboon, Futoshi Nakazawa","doi":"10.1016/j.anaerobe.2024.102921","DOIUrl":"10.1016/j.anaerobe.2024.102921","url":null,"abstract":"<p><strong>Objective: </strong>The genus Veillonella is one of the major and important constitutions of the oral microbiome. A novel anaerobic, Gram-negative coccus belonging to the genus Veillonella was isolated from the saliva of a child. In the present study, the characterization of strain S12025-13^T, is described with the comparison to established species of the genus Veillonella and a novel oral species of the genus Veillonella is proposed.</p><p><strong>Methods: </strong>Strain S12025-13^T was conclusively identified using phenotypic, phylogenetic, genomic and biochemical approach. In phylogenetic analysis, multi-locus species trees (MLST) analysis was also conducted in this study.</p><p><strong>Results: </strong>The strain S12025-13^T showed typical phenotypic characteristics of members of the genus Veillonella. Under anaerobic conditions, the strain produced acetic acid and propionic acid as metabolic end products in a trypticase-yeast extract-heamin medium containing 1 % (w/v) glucose, 1 % (w/v) fructose and 1 % (v/v) sodium lactate. Sequencing of their 16S rRNA genes confirmed that it belongs to the genus Veillonella. Comparative analysis of the 16S rRNA, dnaK and rpoB gene sequences indicated that phylogenetically the strain comprised a distinct novel branch within the genus Veillonella. The novel strain showed 99.77, 97.29, and 99.02 % similarity to partial 16S rRNA, dnaK and rpoB gene sequencing, respectively, to the type strains of the most closely related species. In MLST (selected 79 genes) analysis, strain S12025-13^T formed a distinct taxon with robust bootstrap support (100 %) within the genus Veillonella. Furthermore, strain S12025-13^T shared the highest average nucleotide identity (ANI) value (95.97 %) with the type strain of the most closely related species, \"Veillonella faecalis\" which is not validly published under the International Code of Nomenclature of Prokaryotes (ICNP). Likewise, strain S12025-13^T showed the highest digital DNA-DNA hybridization (dDDH) value (65.00 %) with the type strain of \"V. faecalis\". In addition, strain S12025-13^T formed a distinct branch in this clade with a bootstrap value of 72 % with Veillonella nakazawae and 51 % with \"V. faecalis\" related species of the genus Veillonella in the genome based phylogenetic tree.</p><p><strong>Conclusion: </strong>The novel strain could be discriminated from previously reported species of the genus Veillonella based on partial dnaK gene sequencing, MLST analysis, ANI and dDDH values, and genome-based phylogeny. Based on these observations, this strain represents a novel species, for which the name Veillonella orientalis sp., nov. is proposed. The type strain is S12025-13^T (= JCM 33967^T = CCUG 74596^T).</p>","PeriodicalId":8050,"journal":{"name":"Anaerobe","volume":" ","pages":"102921"},"PeriodicalIF":2.5,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142708881","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":"Comparison of clinical characteristics, risk factors, and outcomes of patients infected with Bacteroides fragilis group at a tertiary care hospital in central China between 2017 and March 2024","authors":"Yongmei Li ,&nbsp;Jing Zhao ,&nbsp;Qiong Ma ,&nbsp;Junhong Xu ,&nbsp;Youhua Yuan ,&nbsp;Qi Zhang ,&nbsp;Wenjuan Yan ,&nbsp;Wenbo Xu ,&nbsp;Zhiyu Yang ,&nbsp;Gang Li ,&nbsp;Lan Gao ,&nbsp;Baoya Wang","doi":"10.1016/j.anaerobe.2024.102922","DOIUrl":"10.1016/j.anaerobe.2024.102922","url":null,"abstract":"<div><h3>Objectives</h3><div>This study aimed to explore the epidemiology, clinical presentation, and risk factors for treatment failure in patients infected with various <em>Bacteroides fragilis</em> group (BFG) species.</div></div><div><h3>Methods</h3><div>We analyzed clinical and laboratory data from 178 patients infected with BFG who were admitted to our hospital between 2017 and 2024. We analyzed categorical data using Chi-square and Fisher exact tests, continuous variables using Student's <em>t</em>-tests or Mann–Whitney <em>U</em>-tests, and risk factors using multivariate logistic regression and Pearson's chi-squared tests.</div></div><div><h3>Results</h3><div><em>Bacteroides fragilis</em> (69.7 %) and <em>Bacteroides thetaiotaomicron</em> (16.9 %) were the most prevalent species among 178 BFG isolates. Most patients had polymicrobial infections, with the following pathogens isolated from concurrent samples: <em>Escherichia coli</em>, <em>Klebsiella</em> spp., and <em>Enterococcus</em> spp. Intra-abdominal sites were most frequently infected with BFG. Patients aged &gt;50 years and those who had intravascular catheters were infected with more other <em>Bacteroides</em> species than <em>B. fragilis</em>. Admission to an ICU, respiratory, renal and cardiovascular diseases, and chest drainage were associated more often with <em>B. thetaiotaomicron</em> than with <em>B. fragilis</em>. Gastrointestinal diseases, tracheal intubation, and ICU admission were associated more frequently with treatment failure in patients infected with <em>B. fragilis</em> whereas solid cancers, renal disease, multiple organ dysfunction syndrome, and tracheal intubation were more likely to be associated with treatment failure in patients infected with other <em>Bacteroides</em> spp.</div></div><div><h3>Conclusions</h3><div>The most prevalent BFG species in the patients were <em>B</em>. <em>fragilis</em> and <em>B</em>. <em>thetaiotaomicron</em>. The demographic characteristics of the patients, underlying diseases, and risk factors for poor clinical outcomes clearly differed among species.</div></div>","PeriodicalId":8050,"journal":{"name":"Anaerobe","volume":"91 ","pages":"Article 102922"},"PeriodicalIF":2.5,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142708878","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Regulatory networks: Linking toxin production and sporulation in Clostridioides difficile.","authors":"Md Kamrul Hasan, Oluchi Alaribe, Revathi Govind","doi":"10.1016/j.anaerobe.2024.102920","DOIUrl":"10.1016/j.anaerobe.2024.102920","url":null,"abstract":"<p><p>Clostridioides difficile has been recognized as an important nosocomial pathogen that causes diarrheal disease as a consequence of antibiotic exposure and costs the healthcare system billions of dollars every year. C. difficile enters the host gut as dormant spores, germinates into vegetative cells, colonizes the gut, and produces toxins TcdA and/or TcdB, leading to diarrhea and inflammation. Spores are the primary transmission vehicle, while the toxins A and B directly contribute to the disease. Thus, toxin production and sporulation are the key traits that determine the success of C. difficile as a pathogen. Both toxins and spores are produced during the late stationary phase in response to various stimuli. This review provides a comprehensive analysis of the current knowledge on the molecular mechanisms, highlighting the regulatory pathways that interconnect toxin gene expression and sporulation in C. difficile. The roles of carbohydrates, amino acids and other nutrients and signals, in modulating these virulence traits through global regulatory networks are discussed. Understanding the links within the gene regulatory network is crucial for developing effective therapeutic strategies against C. difficile infections, potentially leading to targeted interventions that disrupt the co-regulation of toxin production and sporulation.</p>","PeriodicalId":8050,"journal":{"name":"Anaerobe","volume":" ","pages":"102920"},"PeriodicalIF":2.5,"publicationDate":"2024-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142613602","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":"Dogs in Rio de Janeiro as reservoirs of Clostridioides difficile ribotypes causing CDI in humans","authors":"Júlia Meireles ,&nbsp;Renata F.F. Moraes ,&nbsp;Débora Lins ,&nbsp;Thaís da Silveira Oliveira ,&nbsp;Eduardo Butturini de Carvalho ,&nbsp;Kelly Rainha ,&nbsp;Eliane de O. Ferreira","doi":"10.1016/j.anaerobe.2024.102917","DOIUrl":"10.1016/j.anaerobe.2024.102917","url":null,"abstract":"<div><h3>Introduction</h3><div>In the past decade, the incidence of community-acquired <em>Clostridioides difficile</em> infection (CA-CDI) has increased, suggesting a role for community reservoirs such as animals in its spread.</div></div><div><h3>Objective</h3><div>This study aimed to isolate and characterize <em>C. difficile</em> strains from domestic dogs at veterinary clinics to enhance our understanding of <em>C. difficile</em> epidemiology in Rio de Janeiro.</div></div><div><h3>Material and methods</h3><div>For this study 90 stool samples from dogs were collected and cultured in a selective medium (<em>Clostridioides difficile</em> Brucella agar – CDBA) for isolation. Species were identified by MALDI-TOF MS, with confirmation provided by PCR targeting the <em>tpi</em> gene. The antibiotic susceptibility test of the strains was performed using five antibiotics: vancomycin, metronidazole, moxifloxacin, rifampicin, and erythromycin. Strains resistant to metronidazole were further analyzed for the presence of the plasmid pCD-METRO using PCR. The presence of toxin genes (<em>tcdA</em>, <em>tcdB</em>, and <em>cdtB</em>) was investigated, alongside ribotyping and <em>tcdC</em> sequencing analyses. The strains were also tested for biofilm formation and motility.</div></div><div><h3>Results</h3><div><em>C. difficile</em> was isolated in 15.5 % (14/90) of the samples. Among the strains analyzed, 87.71 % (12/14) tested positive for both toxin genes <em>tcd</em>A and <em>tcd</em>B and belonged to ribotypes 106 (10/14) and 014/020 (2/14). The remaining 14.3 % (2/14) were non-toxigenic and were identified as ribotype 010. Regarding the antibiotic profile, 42.85 % (6/14) of the strains exhibited resistance to at least one antibiotic, including vancomycin (1/14) and metronidazole (1/14). The metronidazole-resistant strain was also positive for the plasmid pCD-METRO. All strains exhibited both biofilm formation and motility. Among the 12 toxigenic strains sequenced for the <em>tcdC</em> gene, two exhibited a deletion in the same region as the epidemic strain, NAP1 (RT027).</div></div><div><h3>Conclusion</h3><div>Our study found some overlap between <em>C. difficile</em> ribotypes isolated from dogs and from cases of CDI in humans, and the <em>C. difficile</em> prevalence was higher in dogs with diarrhea (<em>p</em> = 0.034).</div></div>","PeriodicalId":8050,"journal":{"name":"Anaerobe","volume":"90 ","pages":"Article 102917"},"PeriodicalIF":2.5,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142405947","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":"Fructo-oligosaccharides promote butyrate production over citrus pectin during in vitro fermentation by colonic inoculum from pig","authors":"Yanan Zhang ,&nbsp;Chunlong Mu ,&nbsp;Kaifan Yu ,&nbsp;Yong Su ,&nbsp;Erwin G. Zoetendal ,&nbsp;Weiyun Zhu","doi":"10.1016/j.anaerobe.2024.102919","DOIUrl":"10.1016/j.anaerobe.2024.102919","url":null,"abstract":"<div><h3>Objectives</h3><div>Fructo-oligosaccharide (FOS) and citrus pectin (CP) are soluble fibers with different chemical composition. However, their fermentation pattern in large intestine remains unclear.</div></div><div><h3>Methods</h3><div>An <em>in vitro</em> batch fermentation using colonic digesta from pigs as inoculum was employed to investigate the fermentation dynamics of FOS and CP. The monosaccharides and SCFAs contents were assayed by high-performance liquid chromatography and gas chromatography, respectively. And the microbiota community was assessed by 16S rRNA gene high-throughput sequencing.</div></div><div><h3>Results</h3><div>Both FOS and CP were degarded after 6 h, especially to a neglected level in FOS. FOS group showed higher abundances of butyrate-producing bacteria such as <em>Eubacterium rectale</em>, <em>Roseburia faecis</em> and <em>Coprococcus comes</em> and butyrate compared to CP. CP stimulated the growth of pectinolytic microbes <em>Lachnospira pectinoschiza</em>, succinate-producing bacteria <em>Succinivibrio dextrinosolvens</em>, succinate-utilizing bacteria <em>Phascolarctobacterium succinatutens</em> and the production of acetate and propionate compared to FOS. Moreover, the relative abundances of key enzymes (e.g. butyrate kinase) involving in butyrate formation via the butyrate kinase route were upregulated in the FOS group. And the key enzymes (e.g. acetyl-CoA synthetase) associated with propionate production through the succinate pathway were upregulated in the CP group.</div></div><div><h3>Conclusions</h3><div>FOS was preferred to ferment by butyrate-producing bacteria to yield a higher level of butyrate via the butyrate kinase pathway, while CP enhanced the cross-feeding of succinate-producing and succinate-utilizing bacteria to form propionate through the succinate pathway. These findings deepen our understanding on the fermentation characteristics of the soluble fibers, and also provide guidelines for fiber choice in precisely modulating the microbial composition and metabolism in large intestine.</div></div>","PeriodicalId":8050,"journal":{"name":"Anaerobe","volume":"90 ","pages":"Article 102919"},"PeriodicalIF":2.5,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142405948","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":"Oxygen exposure decreases the yield of high-molecular-weight DNA from some anaerobic bacteria and bacterial communities during DNA extraction","authors":"Svetlana Boycheva ,&nbsp;Anthony M. Roberton ,&nbsp;Alessandro Pisaniello ,&nbsp;Bikiran Pardesi ,&nbsp;William Lindsey White ,&nbsp;Kendall D. Clements","doi":"10.1016/j.anaerobe.2024.102915","DOIUrl":"10.1016/j.anaerobe.2024.102915","url":null,"abstract":"<div><h3>Objectives</h3><div>The central challenge in third-generation sequencing lies in meeting the requirements for DNA quality (integrity and purity) and quantity. Therefore, novel improvements in DNA extraction methods are needed to satisfy these requirements. We reasoned that in anaerobic microbial communities, the presence of certain strict anaerobes containing oxygen-activated DNase activity might contribute substantially to the poor integrity of extracted metagenomic DNA (or genomic DNA from some pure cultures) if exposed to air.</div></div><div><h3>Methods</h3><div>To test this hypothesis, we developed an enhanced genomic and metagenomic DNA isolation technique that we applied to a specifically chosen set of both strict and aerotolerant anaerobes, as well as to the hindgut microbiota of a herbivorous marine fish.</div></div><div><h3>Results</h3><div>Considering the quality (or degradation) of extracted DNA obtained under anaerobic versus aerobic conditions, we found that DNA extracted aerobically from cells of some strict anaerobes showed more degradation of high molecular weight DNA than analogous preparations under anaerobic conditions. In contrast, with the selected aerotolerant anaerobes, no discernible difference was found between the molecular sizes of DNA extracted aerobically and anaerobically. Metagenomic DNA extracted from the fish hindgut microbiota showed higher yields and better quality under anaerobic conditions compared to aerobic conditions.</div></div><div><h3>Conclusion</h3><div>Our study effectively demonstrates the advantages of our improved extraction protocol in anaerobic conditions. This is evident through the improved quality of extracted DNA. Such findings may be valuable for studies, especially metagenomic studies, where the quality and quantity of DNA are crucial for downstream analysis.</div></div>","PeriodicalId":8050,"journal":{"name":"Anaerobe","volume":"90 ","pages":"Article 102915"},"PeriodicalIF":2.5,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142399196","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Butyricimonas paravirosa bacteremia associated with acute terminal ileitis: Case report and literature review","authors":"Gregory Whitehill ,&nbsp;Ran Zhuo ,&nbsp;Shangxin Yang","doi":"10.1016/j.anaerobe.2024.102918","DOIUrl":"10.1016/j.anaerobe.2024.102918","url":null,"abstract":"<div><div>We present the first described case of bacteremia due to <em>Butyricimonas paravirosa</em>, a commensal gram-negative anaerobic bacterium identified by whole-genome sequencing in an elderly patient with acute terminal ileitis, who was successfully treated with ceftriaxone and metronidazole. We reviewed eleven previous cases of infection due to other <em>Butyricimonas</em> spp, which can cause a range of diseases but may be treated conservatively with a short antimicrobial course in the appropriate clinical setting. Additionally, while most <em>Butyricimonas</em> spp are susceptible to empiric anaerobic therapy, drug resistance has been reported in some cases.</div></div>","PeriodicalId":8050,"journal":{"name":"Anaerobe","volume":"90 ","pages":"Article 102918"},"PeriodicalIF":2.5,"publicationDate":"2024-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142379900","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Clostridioides difficile toxin B suppresses human neutrophil migration","authors":"Yoshitaka Kimura,&nbsp;Nami Hatayama,&nbsp;Yoshinori Sato,&nbsp;Yusuke Yoshino","doi":"10.1016/j.anaerobe.2024.102916","DOIUrl":"10.1016/j.anaerobe.2024.102916","url":null,"abstract":"<div><div>We investigated the effects of <em>Clostridioides difficile</em> toxin B (TcdB), a major virulence factor in <em>C. difficile</em> infection (CDI), on human neutrophils. TcdB inhibits neutrophil migration via loss of polarity of F-actin polymerization in response to interleukin-8. TcdB facilitates CDI by allowing <em>C. difficile</em> to avert the host immune system.</div></div>","PeriodicalId":8050,"journal":{"name":"Anaerobe","volume":"90 ","pages":"Article 102916"},"PeriodicalIF":2.5,"publicationDate":"2024-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142379901","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Serine affects engulfment during the sporulation process in Clostridium perfringens strain SM101","authors":"Mayo Yasugi ,&nbsp;Akinobu Ohta ,&nbsp;Keiko Takano ,&nbsp;Kanako Yakubo ,&nbsp;Michiko Irie ,&nbsp;Masami Miyake","doi":"10.1016/j.anaerobe.2024.102914","DOIUrl":"10.1016/j.anaerobe.2024.102914","url":null,"abstract":"<div><h3>Objectives</h3><div>Although <em>Clostridium perfringens</em> sporulation is a key event in the pathogenesis of food-borne illness, the molecules and underlying mechanisms responsible for regulating sporulation are incompletely understood. The present study sought to identify amino acids that affect sporulation in <em>C. perfringens</em> strain SM101.</div></div><div><h3>Methods</h3><div>A <em>C. perfringens</em> strain was cultured in the chemically defined medium deficient in an amino acid. The bacterial growth was determined by spectrophotometrically measuring culture turbidity and by calculating colony-forming unit. Morphological characteristics were assessed by phase-contrast microscopy with fluorescent staining and by electron microscopy.</div></div><div><h3>Results</h3><div>The amino acids Arg, Cys, Gly, His, Ile, Leu, Met, Phe, Thr, Trp, Tyr, and Val were important for sporulation, and furthermore, Ser reduced sporulation. The mechanism underlying Ser-induced prevention of sporulation was assessed morphologically. The numbers of bacterial cells in sporulation stage II were significantly higher in the presence than in the absence of Ser. In the presence of Ser, almost all cells were in stage II−III, characterized by polar septation−early engulfment, and did not proceed to late engulfment.</div></div><div><h3>Conclusions</h3><div>These results suggest that Ser accelerated the early stage of sporulation of <em>C. perfringens</em> strain SM101, but disturbed the engulfment process, resulting in reduction of sporulation. To the best of our knowledge, this is the first study reporting that an amino acid affects engulfment during the <em>C. perfringens</em> sporulation process.</div></div>","PeriodicalId":8050,"journal":{"name":"Anaerobe","volume":"90 ","pages":"Article 102914"},"PeriodicalIF":2.5,"publicationDate":"2024-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142379033","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}