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Microbiota- and Pathogen-Specific Contributions to Clostridium Difficile Virulence in the Mouse Model.

紀錄類型:	書目-語言資料,手稿 : Monograph/item
正題名/作者:	Microbiota- and Pathogen-Specific Contributions to Clostridium Difficile Virulence in the Mouse Model./
作者:	Lewis, Brittany Barker.
面頁冊數:	1 online resource (118 pages)
附註:	Source: Dissertation Abstracts International, Volume: 79-03(E), Section: B.
Contained By:	Dissertation Abstracts International79-03B(E).
標題:	Microbiology. -
電子資源:	click for full text (PQDT)
ISBN:	9780355501797

Microbiota- and Pathogen-Specific Contributions to Clostridium Difficile Virulence in the Mouse Model.
Lewis, Brittany Barker.

Microbiota- and Pathogen-Specific Contributions to Clostridium Difficile Virulence in the Mouse Model. - 1 online resource (118 pages)

Source: Dissertation Abstracts International, Volume: 79-03(E), Section: B.

Thesis (Ph.D.)--Weill Medical College of Cornell University, 2017.

Includes bibliographical references

Clostridium difficile is an anaerobic, gram-positive bacterium that is responsible for the majority of hospital-associated gastrointestinal infections. It has been recognized as a pathogen since the 1970s but more recently has become an urgent threat to public health. C. difficile produces two powerful toxins that disrupt the integrity of the colonic epithelium and induce a strong inflammatory response. Susceptible individuals experience symptoms that range from mild, self-limiting diarrhea to fulminant pseudomembranous colitis and even death. However, most healthy individuals are protected from C. difficile infections so long as they are able to maintain a diverse population of commensal bacteria in their gut. Disruptions to these commensals, often from antibiotic therapy, provide the niche C. difficile spores need to germinate, produce toxins, and cause disease. Current first-line therapy for infections is additional antibiotics that lead to a high risk of relapse. In fact, we found that short course antibiotic therapy leaves mice susceptible to additional infections in the days and weeks that the commensal microbiota spends recovering to pre-antibiotic levels. Beyond requiring disruptions to the microbiota before colonization, C. difficile is composed of hundreds of different strain subtypes. The variability in disease severity induced by each of these different subtypes has been hampered by diverse sources of human patient data and has confused the literature for years. We found that the mouse model could be used successfully to quantify the differences in disease burden of phylogenetically diverse C. difficile clinical isolates. Our results demonstrate that differences in observed virulence have less to do with the amount of toxin each isolate produces and more to do with its tolerance to secondary bile acids like lithocholic acid. In addition, whole genome sequencing allows us to identify groups of genes that are associated with highly lethal strains. This work emphasizes the need to evaluate the impact of antibiotic therapy and infecting strain when assessing and treating C. difficile infections.

Electronic reproduction.
Ann Arbor, Mich. :
ProQuest,
2018

Mode of access: World Wide Web

ISBN: 9780355501797Subjects--Topical Terms:

591510
Microbiology.
Index Terms--Genre/Form:

554714
Electronic books.

Microbiota- and Pathogen-Specific Contributions to Clostridium Difficile Virulence in the Mouse Model.
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520 $a Clostridium difficile is an anaerobic, gram-positive bacterium that is responsible for the majority of hospital-associated gastrointestinal infections. It has been recognized as a pathogen since the 1970s but more recently has become an urgent threat to public health. C. difficile produces two powerful toxins that disrupt the integrity of the colonic epithelium and induce a strong inflammatory response. Susceptible individuals experience symptoms that range from mild, self-limiting diarrhea to fulminant pseudomembranous colitis and even death. However, most healthy individuals are protected from C. difficile infections so long as they are able to maintain a diverse population of commensal bacteria in their gut. Disruptions to these commensals, often from antibiotic therapy, provide the niche C. difficile spores need to germinate, produce toxins, and cause disease. Current first-line therapy for infections is additional antibiotics that lead to a high risk of relapse. In fact, we found that short course antibiotic therapy leaves mice susceptible to additional infections in the days and weeks that the commensal microbiota spends recovering to pre-antibiotic levels. Beyond requiring disruptions to the microbiota before colonization, C. difficile is composed of hundreds of different strain subtypes. The variability in disease severity induced by each of these different subtypes has been hampered by diverse sources of human patient data and has confused the literature for years. We found that the mouse model could be used successfully to quantify the differences in disease burden of phylogenetically diverse C. difficile clinical isolates. Our results demonstrate that differences in observed virulence have less to do with the amount of toxin each isolate produces and more to do with its tolerance to secondary bile acids like lithocholic acid. In addition, whole genome sequencing allows us to identify groups of genes that are associated with highly lethal strains. This work emphasizes the need to evaluate the impact of antibiotic therapy and infecting strain when assessing and treating C. difficile infections.
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