STUDIES ON IMMUNITY TO TOXINS OF CLOSTRIDIUM BOTULINUM III

Abstract

A simple and relatively reproducible medium was developed for toxin production by C. botulinum type E. The medium contained 2% proteose peptone, 2% yeast extract, and 1% dextrin. Primary toxicities of approximately 5,000 mouse intraperitoneal LD50 per ml were produced in 5 days at 30oC. This toxicity was increased to 200,000 LD50 per ml by activation with trypsin. The toxin was fractionated by a procedure involving precipitation with ethanol in the cold, extraction of the toxin with calcium chloride solution, and two additional ethanol precipitations. Fractionation of the trypsin-activated culture yielded a product containing approximately 2 x 107 LD50/mgN with a recovery of 55%. The nonactivated fractionated product contained 8.5 x 104 LD50/mgN with a recovery of 40%. Toxins were detoxified in the presence of 0.6% formalin at 33[degree]C and adsorbed on aluminum phosphate. Toxoids prepared from both activated and nonactivated toxins were antigenic in mice.