Clostridium perfringens toxin genotypes in the feces of healthy North Americans.

We investigated the frequency of Clostridium perfringens in the normal fecal flora of healthy North Americans. About half of 43 subjects were colonized with C. perfringens at levels of approximately 10(6)cfu/g feces. Only type A strains were recovered. Spores sometimes outnumbered vegetative cells. Several genotypes were found. Some donors carried two genotypes, some only one. We found no alpha, beta2 or enterotoxin in the stools of any donors. Though some isolates carried toxin genes (e.g. cpe and cpb2) on plasmids, we saw no indication that healthy humans are the reservoir for the chromosomally-borne cpe recovered from cases of C. perfringens food poisoning.