The Molecular Epidemiology of Clostridium perfringens Type A Food Poisoning (1998-02822)

Clostridium perfringens type A food poisoning currently ranks as the second most common foodbome disease in the US. The diarrhetic and cramping symptoms of this illness are caused by C. perfringens enterotoxin (CPE). Recent studies have shown that the CPE gene encoding this enterotoxin can be located on either chromosomal or extrachromosomal DNA. However, only C. perfringens isolates carrying an extrachromosomal CPE can cause nonfoodbome intestinal disease. This project will evaluate four possible explanations for the strong association between chromosomal CPE isolates and food poisoning: i) isolates carrying a chromosomal CPE are predominant in the food poisoning environment,ii) chromosomal CPE isolates are more resistant to food-associated stresses (e.g.cooking) than are isolates carrying an extrachromosomal CPE, iii) the chromosomal CPE is more stable to food-related stress than the extrachromosomal CPE, and iv) food-related stress induces migration of the extrachromosomal CPE onto the chromosome. These studies should improve the safety of the American food supply by distinguishing whether only chromosomal CPE isolates are able to cause foodpoisoning, or if isolates carrying an extrachromosomal CPE can be converted, by food-related stress, into chromosomal CPE isolates.This information will improve the safety of the American Food supply in two ways: I) it will become possible to specifically detect the presence of C. perfringens food poisoning isolates in foods before these foods are consumed, and ii) it will elucidate how/when C. perfringens food poisoning isolates enter foods, which will allow the development of strategies to interfere with the introduction of C.perfringens food poisoning isolates into foods.