Aerobic growth and toxigenicity of Clostridium botulinum types A and B.

Clostridium botulinum types A and B cultured in association with avian skin flora, had similar growth patterns under both aerobic and anaerobic conditions. The selective "C. botulinum isolation" (CBI) medium was found to be especially useful for the recovery and quantitation of small numbers of type A or type B organisms from the mixed cultures. Enzyme immunoassay in conjunction with conventional mouse bioassay provided a practical means for the quantitation of toxigenicity of C. botulinum in avian skin cultures. The amount of toxin produced by type A was always higher than that produced by type B strains. The aerobically incubated type A or type B cultures appeared to be less toxigenic than cultures incubated anaerobically.