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Cefoperazone-treated Mouse Model of Clinically-relevant Clostridium difficile Strain R20291
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Modulation of toxin production by the flagellar regulon in Clostridium difficile

Annie Aubry1, Greg Hussack, Wangxue Chen

  • 1Institute for Biological Sciences, National Research Council of Canada, Ottawa, Ontario, Canada.

Infection and Immunity
|August 2, 2012
PubMed

Insights

Clostridium difficile toxin production is regulated by flagellar genes. Disrupting flagellar formation impacts toxin levels and virulence, revealing complex regulatory networks.

Area of Science:

  • Microbiology
  • Molecular Biology
  • Infectious Diseases

Background:

  • Clostridium difficile is a major cause of healthcare-associated infections.
  • Toxin production is a key virulence factor for C. difficile.
  • The role of flagella in C. difficile toxin regulation is not fully understood.

Purpose of the Study:

  • To investigate the impact of flagellar gene mutations on C. difficile toxin production.
  • To elucidate the relationship between flagellar assembly and virulence gene expression.
  • To explore the regulatory network connecting flagella and toxin synthesis.

Main Methods:

  • Assessing toxin levels using cell-based cytotoxicity assays, proteomics, immunoassay, and immunoblotting.
  • Analyzing the transcription of pathogenicity locus genes (tcdR, tcdB, tcdE, tcdA).
  • Evaluating mutant virulence in a hamster model of C. difficile infection.

Main Results:

  • A fliC mutant showed significantly increased toxin levels and pathogenicity gene transcription.
  • Other flagellar mutants (fliF, fliG, fliM, flhB-fliR) exhibited reduced toxin levels and gene transcription.
  • Mutant strains displayed altered virulence in the hamster infection model.

Conclusions:

  • Flagellar regulon differentially regulates toxin production in C. difficile.
  • Flagellar gene expression is linked to the transcriptional control of virulence genes.
  • This study reveals intricate regulatory networks governing C. difficile virulence.

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