Studies on immunity to toxins of Clostridium botulinum. V. Detoxification of purified type A and type B toxins, and the antigenicity of univalent and bivalent aluminium phosphate adsorbed toxoids.

Fiock, Mary A. (Fort Detrick, Frederick, Md.), Allen Yarinsky, and James T. Duff. Studies on immunity to toxins of Clostridium botulinum. VII. Purification and detoxification of trypsin-activated type E toxin. J. Bacteriol. 82:66-71. 1961.-A procedure was described for production, purification, and conversion to toxoid of the Clostridium botulinum type E trypsin-treated toxin. A medium containing 1.5% trypticase, 0.5% yeast extract, 0.075% cysteine hydrochloride, and 1.0% glucose consistently yielded activated culture toxicities of 300,000 mouse intraperitoneal ld(50)/ml. Purification of the toxin was accomplished by precipitation with ammonium sulfate, extraction with calcium chloride, and reprecipitation with ethanol in the cold. The resulting partially purified toxin had a specific activity of 45,000,000 ld(50)/mg nitrogen. Purified toxins were converted to toxoid by incubation with formalin and adsorbed on aluminum phosphate. Good immune responses were obtained to the toxoids in mice, guinea pigs, and rabbits.