Clostridium difficile-associated cecitis in guinea pigs exposed to penicillin.

Penicillin treatment resulted in lethal hemorrhagic cecitis in seven of eight guinea pigs. Cecal contents at necropsy from all seven animals contained a cytopathic toxin which was neutralized by Clostridium sordellii and C difficile antitoxins. Bacteriologic cultural examinations of these specimens yielded penicillin-sensitive strains of C difficile which produced a similar or identical cytotoxin in vitro. Stools obtained before penicillin administration and cecal contents from control animals lacked a cytotoxin and cultures failed to yield C difficile. Intracecal injection of cell-free supernatant of C difficile broth cultures reproduced the lesion noted with penicillin treatment. These results implicate C difficile as an agent of penicillin-induced lethal hemorrhagic cecitis in guinea pigs.