Production of C2 toxin by Clostridium botulinum types C and D as determined by its vascular permeability activity.

Vascular permeability (VP) activity was demonstrated by intradermal injection of culture supernatants of Clostridium botulinum types C and D and strains producing only C2 toxin. The activity was enhanced markedly by treatment with trypsin. It was abolished by antiserum against C2 toxin and by antisera specific for components I and II of C2 toxin, but not by anti-type C or -type D neurotoxin serum. Of 14 strains examined, 10 had VP activity. No VP activity was demonstrated in the culture supernatants of C. botulinum type A, B, E, or F. These results indicate that VP activity is a function of the C2 toxin elaborated by C. botulinum types C and D and that the toxin possesses VP as well as lethal activities. These findings raise the possibility that VP activity of C2 toxin exerts synergic effect(s) with neurotoxin in the pathogenesis of botulism caused by type C and D strains.