Toxigenic Profile of Clostridium perfringens Strains Isolated from Natural Ingredient Laboratory Animal Diets

Abstract

Clostridium perfringens 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. C. perfringens is an opportunistic enteropathogen capable of producing at least 20 different toxins in various combinations. Strains of C. perfringens are currently categorized into seven toxinotypes (A, B, C, D, E, F & G) based on the presence/absence of four major toxins (alpha, beta, epsilon & iota) and two minor toxins (enterotoxin & netB). Each toxinotype is associated with specific histotoxic and enteric diseases. The Quality Assurance Laboratory (QAL) at the National Institute of Environmental Health Sciences (NIEHS) screens incoming animal feeds for aerobic, enteric pathogens, such as Salmonella spp. and E. coli. Recently, QAL has incorporated anaerobic screening of incoming animal feeds. To date, the lab has isolated numerous Clostridium species, including C. perfringens, from 23 lots of natural-ingredient laboratory animal diets.