ABSTRACT
Clostridium botulinum includes a very heterogeneous group of strains that have been divided into types A through G on the basis of the antigenic specificity of the neurotoxins that are produced. Recent studies have shown that other Clostridium species can also produce botulinum neurotoxins (see Chapters 1 and 4). When biochemical, physiological, serological, and DNA homologies are used to characterize the different strains, this species can be separated into: Group I, proteolytic types A, B, and F and subtypes AB, AF, BA, and BF; Group II, nonproteolytic types B, E, and F; Group III, nonproteolytic types C and D; and Group IV, proteolytic type G.
