title: Association of beta2 toxin production with Clostridium perfringens type A human gastrointestinal disease isolates carrying a plasmid enterotoxin gene.
abstract: 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.
authors.affiliation: Department of Molecular Genetics and Biochemistry, Molecular Virology and Microbiology Graduate Program, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA.
authors.forename: Derek J
authors.initials: DJ
authors.lastname: Fisher
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Miyamoto
authors.forename: Benjamin
authors.initials: B
authors.lastname: Harrison
authors.forename: Shigero
authors.initials: S
authors.lastname: Akimoto
authors.forename: Mahfuzur R
authors.initials: MR
authors.lastname: Sarker
authors.forename: Bruce A
authors.initials: BA
authors.lastname: McClane
mesh_terms: D000595:Amino Acid Sequence; D001427:Bacterial Toxins / Q000235:genetics / Q000378:metabolism* / Q000633:toxicity; D018938:Caco-2 Cells / Q000187:drug effects / Q000382:microbiology; D003015:Clostridium Infections / Q000382:microbiology*; D003016:Clostridium perfringens / Q000235:genetics / Q000378:metabolism / Q000472:pathogenicity*; D017077:Culture Media, Conditioned / Q000494:pharmacology; D004768:Enterotoxins / Q000235:genetics*; D005767:Gastrointestinal Diseases / Q000382:microbiology*; D006801:Humans; D008969:Molecular Sequence Data; D010957:Plasmids / Q000235:genetics; D016133:Polymerase Chain Reaction / Q000379:methods; D017422:Sequence Analysis, DNA; D013171:Spores, Bacterial / Q000235:genetics; D018675:Toxicity Tests
chemical_list: D001427:Bacterial Toxins; D017077:Culture Media, Conditioned; D004768:Enterotoxins; C109896:cpb2 protein, Clostridium perfringens; C035598:enterotoxin, Clostridium