Clostridium difficile : study of the colonization process and the hypervirulence of an epidemic 027 strain
type: Dataset
description: Clostridium difficile is an enteropathogenic bacterium that causes post-antibiotic nosocomial diarrhea and pseudomembranous colitis. During the last decade, the incidence and the severity of C. difficile infections have significantly increased in America and Europe. This evolution seems to be related to the emergence and to the rapid dissemination of a particularly virulent clone of PCR-ribotype 027. The main virulence factors of C. difficile are the TcdA and TcdB cytotoxins which are responsible for intestinal lesions. However, the intestinal colonization by the bacterium is considered as an indispensible step for infection.To better understand the hypervirulence mechanisms of strain 027, we focused on the study of intestinal colonization process of this strain compared to the colonization process of the non-epidemic strain 630Δerm. First, we studied the role of the fibronectin binding protein FbpA. In vitro and in vivo characterization of a mutant FbpA showed the involvement of this protein in the colonization process of the non-epidemic strain 630Δerm. The difficulty of obtaining a mutant in the epidemic strain R20291 027 does not allow us to compare the adhesive properties of FbpA between the two strains.In a second step, we studied the characteristics of flagellar proteins FliC, FliD, FlgE and MotB. We showed that the flagella have a role in the adhesion and colonization of strain 027 and that this role is less important in strain 630Δerm. We also showed that flagella are involved in other cellular processes than adhesion and colonization. A transcriptomic study of a FliC mutant in 027 R20291 shows that flagellin is also involved in toxin production, sporulation and in the adaptation of bacteria to stress conditions. Further study should be performed to better understand the regulation system that governs these different cellular processes. Finally, we performed a transcriptomic analysis of the kinetic of in vivo colonization of the 027 R20291 strain. The study…
identifier: NNT: 2012PA114844
issued: 2026-05-07T16:25:24.922996
language: fr
modified: 2026-05-07T16:25:24.923001
contact point: Organization
  fn: CCSD
keyword: clostridium-difficile
keyword: colonisation
keyword: colonization
keyword: fibronectin-binfing-protein
keyword: flagella
keyword: flagelles
keyword: hypervirulence
keyword: infoeu-reposemanticsdoctoralthesis
keyword: proteine-de-liaison-a-la-fibronectine
keyword: sdvsalife-sciences-q-bioagricultural-sciences
keyword: theses
landing page: https://theses.hal.science/tel-00922985

Clostridium difficile : study of the colonization process and the hypervirulence of an epidemic 027 strain
type: Distribution
format: HTML
issued: 2026-05-07T16:25:24.926174
modified: 2026-05-07T16:25:24.912133
access URL: https://theses.hal.science/tel-00922985

test_moissonnage_selune
type: Agent