The Molecular Epidemiology of Clostridium perfringens type A Food Poisoning (2001-02517)

Clostridium perfringens type A food poisoning is the third most commonly reported foodborne illness in the USA. The diarrheal and cramping symptoms of this foodborne illness are caused by C. perfringens enterotoxin. The enterotoxin is also important in the pathogenesis of certain C. perfringens non-foodborne gastrointestinal (GI) diseases, such as antibiotic-associated diarrhea. Recent studies revealed that C. perfringens food poisoning isolates carry their enterotoxin gene on the chromosome, but C. perfringens isolates causing non-foodborne diarrheas carry their enterotoxin gene on extra-chromosomal DNA, i.e., plasmids. It was also demonstrated that the spores and vegetative cells of C. perfringens food poisoning isolates are more heat-resistant than thes pores and cells of C. perfringens non-foodborne GI disease isolates. Based upon those previous findings, the investigators will now develop a simple PCR-based diagnostic assay capable of distinguishing between C. perfringens food poisoning isolates carrying a chromosomal enterotoxin gene and C. perfringens non-foodborne GI disease isolates carrying a plasmid enterotoxin gene. They will then utilize that assay to identify the reservoir(s) for C. perfringens food poisoning isolates by surveying foods, human feces,and household dust for the presence of C. perfringens isolates carrying a chromosomal enterotoxin gene. The final aim of this project will involve investigating the physiologic basis for the greater heat resistance of food poisoning isolates. Collectively, these studies should lead to rational strategies aimed at lowering the occurrence of C. perfringens type A food poisoning by 1) reducing food contamination with C. perfringens food poisoning isolates and 2) increasing the killing of those isolates that do enter foods.