Development of a duplex PCR genotyping assay for distinguishing Clostridium perfringens type A isolates carrying chromosomal enterotoxin (cpe) genes from those carrying plasmid-borne enterotoxin (cpe) genes

About 5% of Clostridium perfringens type A isolates carry the cpe gene encoding the C. perfringens enterotoxin. Those cpe-positive type A isolates are important causes of food-poisoning and non-food-borne cases of diarrheas in humans, as well as certain veterinary cases of diarrhea. Previous studies have determined that the enterotoxigenic type A isolates causing both non-food-borne human gastrointestinal disease and veterinary disease carry their cpe genes on plasmids, while the type A isolates causing human food poisoning carry a chromosomal cpe gene. The present study reports on the successful development of a duplex PCR assay that can rapidly genotype enterotoxigenic type A isolates (i.e., determine whether those cpe-positive isolates carry a chromosomal or a plasmid-borne cpe gene). The availability of this rapid cpe genotyping assay capable of handling large numbers of samples provides a powerful new investigative tool for diagnostic, epidemiologic, and basic research purposes.