Use of ganglioside affinity filters to identify toxigenic strains of Clostridium botulinum types C and D.

Clostridium botulinum neurotoxin is synthesized by toxic clones grown anaerobically on ganglioside affinity filters. The toxin binds to the filters and is detected by reaction with 125I-immunoglobulin G from type-specific antitoxin. Toxin spots from culture filtrates were similarly identified. The C. botulinum type C and D strains were selected for developing this affinity filter assay because synthesis of the C1 and D toxins is bacteriophage dependent. Toxigenic clones were distinguished from prophage-cured atoxigenic derivatives. These studies represent a first step toward the development of a general nonbiological screening procedure for identifying botulinal toxin and toxigenic cells. The affinity filter methodology should facilitate genetic analysis of the basis of C. botulinum toxicity.