Association of beta2 Toxin Production With Clostridium Perfringens Type A Human Gastrointestinal Disease Isolates Carrying a Plasmid Enterotoxin Gene

Mol Microbiol. 2005 May;56(3):747-62. doi: 10.1111/j.1365-2958.2005.04573.x.


Clostridium perfringens type A isolates carrying an enterotoxin (cpe) gene are an important cause of human gastrointestinal diseases, including food poisoning, antibiotic-associated diarrhoea (AAD) and sporadic diarrhoea (SD). Using polymerase chain reaction (PCR), the current study determined that the cpb2 gene encoding the recently discovered beta2 toxin is present in <15% of food poisoning isolates, which typically carry a chromosomal cpe gene. However, >75% of AAD/SD isolates, which usually carry a plasmid cpe gene, tested cpb2(+) by PCR. Western blot analysis demonstrated that >97% of those cpb2(+)/cpe(+) AAD/SD isolates can produce CPB2. Additional PCR analyses, sequencing studies and pulsed field gel electrophoresis experiments determined that AAD/SD isolates carry cpb2 and cpe on the same plasmid when IS1151 sequences are present downstream of cpe, but cpb2 and cpe are located on different plasmids in AAD/SD isolates where IS1470-like sequences are present downstream of cpe. Those analyses also demonstrated that two different CPB2 variants (named CPB2h1 or CPB2h2) can be produced by AAD/SD isolates, dependent on whether IS1470-like or IS1151 sequences are present downstream of their cpe gene. CPB2h1 is approximately 10-fold more cytotoxic for CaCo-2 cells than is CPB2h2. Collectively, these results suggest that CPB2 could be an accessory toxin in C. perfringens enterotoxin (CPE)-associated AAD/SD.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Bacterial Toxins / genetics
  • Bacterial Toxins / metabolism*
  • Bacterial Toxins / toxicity
  • Caco-2 Cells / drug effects
  • Caco-2 Cells / microbiology
  • Clostridium Infections / microbiology*
  • Clostridium perfringens / genetics
  • Clostridium perfringens / metabolism
  • Clostridium perfringens / pathogenicity*
  • Culture Media, Conditioned / pharmacology
  • Enterotoxins / genetics*
  • Gastrointestinal Diseases / microbiology*
  • Humans
  • Molecular Sequence Data
  • Plasmids / genetics
  • Polymerase Chain Reaction / methods
  • Sequence Analysis, DNA
  • Spores, Bacterial / genetics
  • Toxicity Tests


  • Bacterial Toxins
  • Culture Media, Conditioned
  • Enterotoxins
  • cpb2 protein, Clostridium perfringens
  • enterotoxin, Clostridium

Associated data

  • GENBANK/AY737555