THE ENTEROTOXIN GENE (CPE) OF CLOSTRIDIUM-PERFRINGENS CAN BE CHROMOSOMAL OR PLASMID-BORNE

The location of the ope gene, encoding the enterotoxin responsible for food poisoning in humans, has been studied in a series of enterotoxig enic Clostridium perfringens strains by means of pulsed field gel elec trophoresis of genomic DNA. The cpe gene was found at the same chromos omal locus in strains associated with food poisoning in humans and was shown to be linked to a repetitive sequence, the HindIII repeat, and an open reading frame, ORF3, that may be part of an insertion sequence . In contrast, when the strains originated from domesticated livestock ope was located on a large episome where it was often close to a copy of the transposable element IS1151. In these cases, the HindIII repea t was not linked to the ope gene although this was generally preceded by ORF3.