Clostridium perfringens beta2-toxin in an African elephant (Loxodonta africana) with ulcerative enteritis.

A 22-year-old female African elephant (Loxodonta africana) developed diarrhoea of unknown cause which lasted for two days. The animal was euthanased after it remained recumbent and refused to get up. Gross pathological changes were present mainly in the gastrointestinal tract. The intestinal contents were watery and dark brown. Several areas of the mucosa of the small intestine were covered minimally to moderately with fibrin and had a few 0.1 x 10 to 15 cm linear ulcerations. Microscopical lesions consisted of discrete areas of necrosis of the surface and crypt epithelium without overt inflammatory infiltrates. Culture of the small intestinal contents resulted in a moderate growth of Clostridium perfringens. No salmonella were found in the small or large intestine. PCR of the isolate of C. perfringens revealed the presence of the beta2-toxin gene cpb2 and the alpha-toxin gene cpa but no other known toxin genes. The expression of the beta2-toxin gene in vivo was demonstrated by the immunohistochemical localisation of the beta2-toxin to the microscopical lesions in the small intestine.