Phase variation of Clostridium difficile virulence factors

Gut Microbes. 2018 Jan 2;9(1):76-83. doi: 10.1080/19490976.2017.1362526. Epub 2017 Sep 21.


Clostridium difficile is a leading cause of nosocomial infections, causing disease that ranges from mild diarrhea to potentially fatal colitis. A variety of surface proteins, including flagella, enable C. difficile colonization of the intestine. Once in the intestine, toxigenic C. difficile secretes two glucosylating toxins, TcdA and TcdB, which elicit inflammation and diarrheal disease symptoms. Regulation of colonization factors and TcdA and TcdB is an intense area of research in C. difficile biology. A recent publication from our group describes a novel regulatory mechanism that mediates the ON/OFF expression of co-regulated virulence factors of C. difficile, flagella and toxins. Herein, we review key findings from our work, present new data, and speculate the functional consequence of the ON/OFF expression of these virulence factors during host infection.

Keywords: Clostridium difficile; RecV; flagella; recombination; toxins.

Publication types

  • Research Support, N.I.H., Extramural
  • Review

MeSH terms

  • Bacterial Proteins / genetics*
  • Bacterial Proteins / metabolism
  • Bacterial Toxins / genetics
  • Bacterial Toxins / metabolism
  • Clostridioides difficile / genetics*
  • Clostridioides difficile / metabolism
  • Clostridioides difficile / pathogenicity
  • Clostridium Infections / microbiology*
  • Flagella / genetics
  • Flagella / metabolism
  • Gene Expression Regulation, Bacterial*
  • Humans
  • Models, Genetic
  • Virulence / genetics
  • Virulence / immunology
  • Virulence Factors / genetics*
  • Virulence Factors / metabolism


  • Bacterial Proteins
  • Bacterial Toxins
  • Virulence Factors