Factors affecting the toxicity of rotting carcasses containing Clostridium botulinum type C

Mice killed shortly after receiving 1300-3000 spores of Clostridium botulinum type C per os were incubated at one of four chosen temperatures together with bottles of cooked meat medium seeded with a similar inoculum. After incubation the rotting carcasses were homogenized. Sterile membrane filtrates of the homogenates (10-20.8%, w/v) and pure cultures were then titrated for toxicity. A temperature of 37 degrees C produced less toxicity in most carcasses than in cultures. At 30 degrees C, however, toxicity (often 2 X 10(5) to 2 X 10(6) mouse intraperitoneal LD/g or ml) was roughly similar in both systems, and some carcasses and cultures were still toxic (2 X 10(4) to 2 X 10(5) LD/g or ml) after 349 days. Surprisingly, at 23 degrees C, through greatly reduced in the cultures, toxicity was high in many carcasses for at least 28 days. Little or no toxin was produced in either system at 16 degrees C. Unfiltered homogenates (17.8-22.5%, w/v; dose 0.25 ml per os) of toxic carcasses incubated at 30 degrees C for 7 days invariably produced death from botulism, often within as little as 4 h, but a 1 in 10 dilution produced less than 100% mortality.