Pub Date : 2015-01-01Epub Date: 2015-12-03DOI: 10.15226/sojmid/3/3/00141
Pradeep Selvaraj, Rohit Gupta, Kenneth M Peterson
Virulence gene regulation in Vibrio cholerae is under the control of the ToxR-ToxT regulatory cascade. Chemotaxis and net motility have been shown to influence the infectivity of Vibrio cholerae. V. cholerae toxR mutants do not synthesize proteins required for chemotaxis towards mucus. The inability of the toxR mutant strain to recognize and swim towards mucus is due to their failure to synthesize AcfB, a methyl-accepting chemotaxis protein. AcfB has previously been shown to be involved in intestinal colonization using the infant mouse model of cholera infection. Wild type V. cholerae recognizes galactose-6-sulfate in the capillary tube assay whereas V. cholerae acfB mutants fail to migrate into the capillary tubes. Vibrio strains carrying a mutation in tcpI, a ToxR regulated gene found within the Vibrio Pathogenicity Island (VPI), which encodes a methyl accepting chemotaxis protein are fully chemotactic towards mucus and galactose-6-sulfate.
{"title":"The <i>Vibrio cholerae ToxR</i> Regulon Encodes Host-Specific Chemotaxis Proteins that Function in Intestinal Colonization.","authors":"Pradeep Selvaraj, Rohit Gupta, Kenneth M Peterson","doi":"10.15226/sojmid/3/3/00141","DOIUrl":"https://doi.org/10.15226/sojmid/3/3/00141","url":null,"abstract":"<p><p>Virulence gene regulation in <i>Vibrio cholerae</i> is under the control of the <i>ToxR</i>-ToxT regulatory cascade. Chemotaxis and net motility have been shown to influence the infectivity of <i>Vibrio cholerae. V. cholerae toxR</i> mutants do not synthesize proteins required for chemotaxis towards mucus. The inability of the <i>toxR</i> mutant strain to recognize and swim towards mucus is due to their failure to synthesize AcfB, a methyl-accepting chemotaxis protein. AcfB has previously been shown to be involved in intestinal colonization using the infant mouse model of cholera infection. Wild type <i>V. cholerae</i> recognizes galactose-6-sulfate in the capillary tube assay whereas <i>V. cholerae acfB</i> mutants fail to migrate into the capillary tubes. Vibrio strains carrying a mutation in <i>tcpI</i>, a <i>ToxR</i> regulated gene found within the Vibrio Pathogenicity Island (VPI), which encodes a methyl accepting chemotaxis protein are fully chemotactic towards mucus and galactose-6-sulfate.</p>","PeriodicalId":74841,"journal":{"name":"SOJ microbiology & infectious diseases","volume":"3 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2015-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4872866/pdf/nihms775589.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"34416671","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}
Pub Date : 2014-01-01Epub Date: 2014-06-27DOI: 10.15226/sojmid/2/3/00122
Sumathi Sankaran Walters, Antonio Quiros, Matthew Rolston, Irina Grishina, Jay Li, Anne Fenton, Todd Z DeSantis, Anne Thai, Gary L Andersen, Peggy Papathakis, Raquel Nieves, Thomas Prindiville, Satya Dandekar
Objective: The human intestine harbors trillions of commensal microbes that live in homeostasis with the host immune system. Changes in the composition and complexity of gut microbial communities are seen in inflammatory bowel disease (IBD), indicating disruption in host-microbe interactions. Multiple factors including diet and inflammatory conditions alter the microbial complexity. The goal of this study was to develop an optimized methodology for fecal sample processing and to detect changes in the gut microbiota of patients with Crohn's disease receiving specialized diets.
Design: Fecal samples were obtained from patients with Crohn's disease in a pilot diet crossover trial comparing the effects of a specific carbohydrate diet (SCD) versus a low residue diet (LRD) on the composition and complexity of the gut microbiota and resolution of IBD symptoms. The gut microbiota composition was assessed using a high-density DNA microarray PhyloChip.
Results: DNA extraction from fecal samples using a column based method provided consistent results. The complexity of the gut microbiome was lower in IBD patients compared to healthy controls. An increased abundance of Bacteroides fragilis (B. fragilis) was observed in fecal samples from IBD positive patients. The temporal response of gut microbiome to the SCD resulted in an increased microbial diversity while the LRD diet was associated with reduced diversity of the microbial communities.
Conclusion: Changes in the composition and complexity of the gut microbiome were identified in response to specialized carbohydrate diet. The SCD was associated with restructuring of the gut microbial communities.
目的：人体肠道中蕴藏着数万亿的共生微生物，它们与宿主免疫系统共生共存。炎症性肠病（IBD）会导致肠道微生物群落的组成和复杂性发生变化，这表明宿主与微生物之间的相互作用受到了干扰。包括饮食和炎症条件在内的多种因素会改变微生物的复杂性。本研究的目的是开发一种优化的粪便样本处理方法，并检测接受特殊饮食的克罗恩病患者肠道微生物群的变化：在一项饮食交叉试验中，克罗恩病患者的粪便样本被采集，该试验比较了特定碳水化合物饮食（SCD）和低残留饮食（LRD）对肠道微生物群的组成和复杂性以及 IBD 症状缓解的影响。使用高密度 DNA 微阵列 PhyloChip 评估了肠道微生物群的组成：结果：使用柱式方法从粪便样本中提取 DNA 的结果一致。与健康对照组相比，IBD 患者肠道微生物群的复杂程度较低。在 IBD 阳性患者的粪便样本中观察到丰度更高的脆弱拟杆菌（B. fragilis）。肠道微生物组对 SCD 的时间反应导致微生物多样性增加，而 LRD 饮食则与微生物群落多样性减少有关：结论：肠道微生物组的组成和复杂性的变化是对特殊碳水化合物饮食的反应。结论：肠道微生物组的组成和复杂性的变化与特殊碳水化合物膳食有关，特殊碳水化合物膳食与肠道微生物群落的重组有关。
{"title":"Analysis of Gut Microbiome and Diet Modification in Patients with Crohn's Disease.","authors":"Sumathi Sankaran Walters, Antonio Quiros, Matthew Rolston, Irina Grishina, Jay Li, Anne Fenton, Todd Z DeSantis, Anne Thai, Gary L Andersen, Peggy Papathakis, Raquel Nieves, Thomas Prindiville, Satya Dandekar","doi":"10.15226/sojmid/2/3/00122","DOIUrl":"10.15226/sojmid/2/3/00122","url":null,"abstract":"<p><strong>Objective: </strong>The human intestine harbors trillions of commensal microbes that live in homeostasis with the host immune system. Changes in the composition and complexity of gut microbial communities are seen in inflammatory bowel disease (IBD), indicating disruption in host-microbe interactions. Multiple factors including diet and inflammatory conditions alter the microbial complexity. The goal of this study was to develop an optimized methodology for fecal sample processing and to detect changes in the gut microbiota of patients with Crohn's disease receiving specialized diets.</p><p><strong>Design: </strong>Fecal samples were obtained from patients with Crohn's disease in a pilot diet crossover trial comparing the effects of a specific carbohydrate diet (SCD) versus a low residue diet (LRD) on the composition and complexity of the gut microbiota and resolution of IBD symptoms. The gut microbiota composition was assessed using a high-density DNA microarray PhyloChip.</p><p><strong>Results: </strong>DNA extraction from fecal samples using a column based method provided consistent results. The complexity of the gut microbiome was lower in IBD patients compared to healthy controls. An increased abundance of <i>Bacteroides fragilis (B. fragilis)</i> was observed in fecal samples from IBD positive patients. The temporal response of gut microbiome to the SCD resulted in an increased microbial diversity while the LRD diet was associated with reduced diversity of the microbial communities.</p><p><strong>Conclusion: </strong>Changes in the composition and complexity of the gut microbiome were identified in response to specialized carbohydrate diet. The SCD was associated with restructuring of the gut microbial communities.</p>","PeriodicalId":74841,"journal":{"name":"SOJ microbiology & infectious diseases","volume":"2 3","pages":"1-13"},"PeriodicalIF":0.0,"publicationDate":"2014-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5944867/pdf/nihms675493.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"36094813","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}
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