Isolation of a Common Cell Wall Antigen from the Proteolytic Strains of Clostridium botulinum

A protein‐rich antigen was extracted from the cell walls of Clostridium botulinum type A strain 190L by relatively mild treatments with detergents, tryptic digestion or cell wall autolysis. The cell wall antigen was relatively labile, and destroyed by acid or formamide hydrolysis. Immunodiffusion studies with the trypsin‐treated cell wall extracts from various strains of C. botulinum indicated that the antigenic cell wall polymers among the proteolytic strains of types A, B and F but not among the nonproteolytic strains of C. botulinum shared a common antigenic specificity.