1Copenhagen Zoo, Frederiksberg, Denmark; 2Center for Zoo and Wild Animal Health, Department of Large Animal Sciences, Royal Veterinary and Agricultural University, Frederiksberg, Denmark; 3Department of Veterinary Pathobiology, Royal Veterinary and Agricultural University, Frederiksberg, Denmark; 4Department of Gastrointestinal and Parasitic Infections, Statens Serum Institut, Copenhagen, Denmark
Abstract
Altered behavior, anorexia, and listlessness were observed in four of five adult captive female Asian elephants (Elephas maximus). Two animals recovered, while two died after 2 days. The dead elephants were subjected to postmortem examination including histopathology, demonstrating fibrinonecrotic enteritis, and colitis.
Clostridium difficile was isolated from both dead elephants and from the feces of the two surviving affected animals and identified by selective cultivation and PCR identification. All isolates had the tcdA and tcdB toxin genes and were positive in a toxigenic culture assay. C. difficile toxin from the intestinal content of one of the fatal cases was demonstrated using cell-culture based cytotoxin assays.
Clostridium perfringens type A and Clostridium septicum were also isolated from both dead animals. Although C. perfringens has been associated with ulcerative enteritis in an elephant,1 in this case these isolates likely are incidental, as C. perfringens enterotoxin was not demonstrated, and as C. septicum is well known for producing rapid postmortem overgrowth.
Amplified fragment length polymorphism typing, showed that the C. difficile isolates recovered from the outbreak, all had the same fingerprint profile, indicating that all four elephants were affected by the same bacterial clone.
These findings appear to be the first to demonstrate that C. difficile may cause enterocolitis in elephants. The results emphasize the need to regard this organism as potentially dangerous for elephants. Although there was no prior exposure to antibiotic agents in this case, caution is recommended when treating elephants with antibiotics, as this may trigger C. difficile induced enterocolitis in other species, most notably humans and horses.2
Literature Cited
1. Bacciarini, L.N., O. Pagan, J. Frey, and A. Grone. 2001. Clostridium perfringens beta2-toxin in an African elephant (Loxodonta africana) with ulcerative enteritis. Vet Rec. 149:618–20.
2. Songer, J.G. 1996. Clostridial enteric diseases of domestic animals. Clin Microbiol Rev. 9:216–234.