A New Method for the Large-Scale Production of High-Titre Botulinum Formol-Toxoid Types C and D

Abstract

Large numbers of cattle and sheep die annually in S. Africa as a result of eating carrion infected with Clostridium botulinum Types C and D. Immunization with formol-toxoids has proved very successful in controlling the disease. C. botulinum Types C and D were grown in intussuscepted cellophane tubes immersed in nutrient medium made from corn-steep liquor. The resulting high-titer toxin contained up to 130 x 106 M.L.D. (for mouse) per mg. protein N. This could be readily toxoided with 0.4% formalin and yielded a product which could be diluted considerably for use, and which contained as little as 0.001 mg. protein N per cattle dose. This relatively pure "dialysate" toxoid was adsorbed on aluminum phosphate (Holt''s method) for use. The dialysate toxoids were 1000 to 8000 times as potent as conventionally prepd. toxoids. The cellophane culture method used allowed the production of almost unlimited amts. of relatively pure high-titer vaccine, at a very low cost in space, materials, labor and effort.