Toxigenic Profile of Strains Isolated from Natural Ingredient Laboratory Animal Diets.

is an anaerobic, gram-positive, spore-forming bacterium that ubiquitously inhabits a wide variety of natural environments including the gastrointestinal tract of humans and animals. is an opportunistic enteropathogen capable of producing at least 20 different toxins in various combinations. Strains of are currently categorized into 7 toxinotypes (A, B, C, D, E, F, and G) based on the presence or absence of 6 typing-toxins (α, β, epsilon, iota, enterotoxin, and netB). Each toxinotype is associated with specific histotoxic and enteric diseases. Spontaneous enteritis due to has been reported in laboratory animals; however, the source of the bacteria was unknown. The Quality Assurance Laboratory (QAL) at the National Institute of Environmental Health Sciences (NIEHS) routinely screens incoming animal feeds for aerobic, enteric pathogens, such as spp. and Recently, QAL incorporated anaerobic screening of incoming animal feeds. To date, the lab has isolated numerous species, including from 23 lots of natural ingredient laboratory animal diets. Published reports of isolation from laboratory animal feeds could not be found in the literature. Therefore, we performed a toxin profile screen of our isolated strains of using PCR to determine which toxinotypes were present in the laboratory animal diets. Our results showed that most strains we isolated from the laboratory animal feed were toxinotype A with most strains also possessing the theta toxin. Two of the strains also possessed the β toxin. Our results demonstrated the presence of in nonsterile, natural ingredient feeds for laboratory animals which could serve as a source of this opportunistic pathogen.