Serological Specificity of Types A and B Botulinal Toxins and Antitoxins

Abstract

Summary

Rabbit, National Communicable Disease Center (NCDC) equine, and International Standard antitoxins to types A and B botulinal toxins were compared by passive hemagglutination (HA), hemagglutination inhibition (HI), and gel-diffusion. The HA reactions in general were quite specific, although cross-reactions were observed. The extent of cross-reaction was greater with B antitoxins and A botulinal toxoid-sensitized red blood cells. The different antitoxins behaved similarly in HI and gel-diffusions, though the reactions of the NCDC and International antitoxins were weaker than those of rabbit antitoxins in gel-diffusions. Hemagglutination inhibition and gel-diffusion reactions with toxic cultures suggested that the in vitro specificity of the A toxin-antitoxin did not involve neutralizing antibodies. Hemagglutination inhibitions and gel-diffusions with B toxins did not resolve the question of the involvement of neutralizing antibodies in in vitro specificity, since fairly toxic cultures inhibited HA and formed bands believed to be associated with type specificity, whereas a virtually non-toxic B culture neither inhibited HA nor formed a line of identity with the type specific systems in gel-diffusion.