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Identification of a two-component VirR/VirS regulon in Clostridium perfringens

Kaori Ohtani1, Hideki Hirakawa, Kousuke Tashiro

  • 1Department of Bacteriology, Graduate School of Medical Science, Kanawaza University, 13-1 Takara-Machi Kanazawa, Ishikawa 920-8640, Japan.

Anaerobe
|October 20, 2009
PubMed

Insights

The VirR/VirS-VR-RNA system globally regulates Clostridium perfringens genes. This system controls virulence factors and cellular functions essential for the pathogen

Area of Science:

  • Microbiology
  • Molecular Biology
  • Genetics

Background:

  • Clostridium perfringens is a Gram-positive anaerobic pathogen causing gas gangrene, a severe and rapidly progressing infection.
  • Toxin production in C. perfringens is regulated by the two-component VirR/VirS system and a regulatory RNA (VR-RNA).

Purpose of the Study:

  • To elucidate the precise regulatory network controlled by the VirR/VirS-VR-RNA system in C. perfringens.
  • To identify genes and cellular functions regulated by this cascade.

Main Methods:

  • Microarray screening was performed using VirR/VirS and VR-RNA-deficient mutants.
  • Quantitative reverse transcription PCR (qRT-PCR) analysis was used to confirm gene regulation.

Main Results:

  • The VirR/VirS-VR-RNA regulatory cascade controls 147 genes, including 30 single genes and 21 putative operons.
  • Key virulence-related genes (alpha-toxin, kappa-toxin, hyaluronidases, sialidase, capsular polysaccharide synthesis) are regulated.
  • Genes involved in catalytic enzymes, transport, and energy metabolism are also under the control of this system.

Conclusions:

  • The VirR/VirS-VR-RNA system acts as a global gene regulator in C. perfringens.
  • This system likely controls multiple cellular functions crucial for pathogen survival, multiplication, and pathogenesis, contributing to gas gangrene.

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