CdtR-mediated regulation of toxin production in Clostridium difficile

Clostridium difficile is the leading cause of hospital-associated diarrhoea in the developed world. Its pathogenicity is elicited by the production of up to three toxins: the monoglucosyltransferases TcdA and TcdB, and the ADP-ribosyltransferase, CDT. This thesis describes the generation and charact...

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Main Author: Bilverstone, Terry W.
Format: Thesis (University of Nottingham only)
Language:English
Published: 2019
Subjects:
Online Access:https://eprints.nottingham.ac.uk/56279/
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author Bilverstone, Terry W.
author_facet Bilverstone, Terry W.
author_sort Bilverstone, Terry W.
building Nottingham Research Data Repository
collection Online Access
description Clostridium difficile is the leading cause of hospital-associated diarrhoea in the developed world. Its pathogenicity is elicited by the production of up to three toxins: the monoglucosyltransferases TcdA and TcdB, and the ADP-ribosyltransferase, CDT. This thesis describes the generation and characterisation of twenty one chromosomally distinct mutants of C. difficile, to primarily study the genetic regulation of toxin production by the two-component system (TCS) transcriptional regulator, CdtR. R20291ΔPaLoc model strains devoid of TcdA/TcdB activity, were generated to study CDT and the cdtR gene deleted and reintegrated at the pyrE locus. The application of these strains to in vitro cytotoxicity assays developed herein, established that CdtR was required for the production of CDT to cytotoxic levels in a PCR-ribotype (RT) 027 stain. The creation of a cdtR deletion mutation in the RT 012 strain 630Δerm established that CdtR played no role in TcdA/TcdB production in this strain. Thereafter, model strains expressing (de)phosphomimetic CdtR phospho-variants were generated. Their application provided strong evidence to suggest that CdtR was activated by phosphorylation of Asp61. In contrast, the RT 078 CdtR homolog was shown to be non-functional. Nine potential TCS histidine kinase interaction partners (IPs) for CdtR, were chromosomally altered. One potential IP was identified, CdtS1, which was affected in the production of CDT, TcdA and TcdB.
first_indexed 2025-11-14T20:33:34Z
format Thesis (University of Nottingham only)
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institution University of Nottingham Malaysia Campus
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language English
last_indexed 2025-11-14T20:33:34Z
publishDate 2019
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spelling nottingham-562792025-02-28T14:26:25Z https://eprints.nottingham.ac.uk/56279/ CdtR-mediated regulation of toxin production in Clostridium difficile Bilverstone, Terry W. Clostridium difficile is the leading cause of hospital-associated diarrhoea in the developed world. Its pathogenicity is elicited by the production of up to three toxins: the monoglucosyltransferases TcdA and TcdB, and the ADP-ribosyltransferase, CDT. This thesis describes the generation and characterisation of twenty one chromosomally distinct mutants of C. difficile, to primarily study the genetic regulation of toxin production by the two-component system (TCS) transcriptional regulator, CdtR. R20291ΔPaLoc model strains devoid of TcdA/TcdB activity, were generated to study CDT and the cdtR gene deleted and reintegrated at the pyrE locus. The application of these strains to in vitro cytotoxicity assays developed herein, established that CdtR was required for the production of CDT to cytotoxic levels in a PCR-ribotype (RT) 027 stain. The creation of a cdtR deletion mutation in the RT 012 strain 630Δerm established that CdtR played no role in TcdA/TcdB production in this strain. Thereafter, model strains expressing (de)phosphomimetic CdtR phospho-variants were generated. Their application provided strong evidence to suggest that CdtR was activated by phosphorylation of Asp61. In contrast, the RT 078 CdtR homolog was shown to be non-functional. Nine potential TCS histidine kinase interaction partners (IPs) for CdtR, were chromosomally altered. One potential IP was identified, CdtS1, which was affected in the production of CDT, TcdA and TcdB. 2019-07-19 Thesis (University of Nottingham only) NonPeerReviewed application/pdf en arr https://eprints.nottingham.ac.uk/56279/1/T.%20Bilverstone-thesis-corrected-final-merged.pdf Bilverstone, Terry W. (2019) CdtR-mediated regulation of toxin production in Clostridium difficile. PhD thesis, University of Nottingham. Clostridium difficile Parthenogenesis Binary toxin TcdA TcdB
spellingShingle Clostridium difficile
Parthenogenesis
Binary toxin
TcdA
TcdB
Bilverstone, Terry W.
CdtR-mediated regulation of toxin production in Clostridium difficile
title CdtR-mediated regulation of toxin production in Clostridium difficile
title_full CdtR-mediated regulation of toxin production in Clostridium difficile
title_fullStr CdtR-mediated regulation of toxin production in Clostridium difficile
title_full_unstemmed CdtR-mediated regulation of toxin production in Clostridium difficile
title_short CdtR-mediated regulation of toxin production in Clostridium difficile
title_sort cdtr-mediated regulation of toxin production in clostridium difficile
topic Clostridium difficile
Parthenogenesis
Binary toxin
TcdA
TcdB
url https://eprints.nottingham.ac.uk/56279/