Comparison of toxins of Clostridium butyricum and Clostridium botulinum type E.

AUTOR(ES)
RESUMO

The toxin of Clostridium butyricum strains isolated from two infants with botulism is neutralized by antitoxin for type E botulinum toxin. This toxin and that of a C. botulinum type E strain were purified by the same protocol. Both toxins were Mr 145,000 proteins which, when activated with trypsin, were composed of an H subunit of Mr 105,000 and an L subunit of Mr 50,000. The activated specific toxicity of purified butyricum toxin based on an intravenous assay was 2 X 10(8) mouse 50% lethal doses (LD50s)/mg of protein, but that based on an intraperitoneal assay was 7 X 10(7) LD50s/mg, compared with 6 X 10(7) LD50s/mg for type E toxin as determined by both methods. Immunodiffusion tests with antitoxin raised with type E toxin indicated that the two toxins were serologically very similar except for a spur formed by type E toxin. The close similarities of the two toxins suggest that toxigenic C. butyricum could arise when a wild-type strain, which is normally nontoxigenic, acquires the toxin gene of a C. botulinum type E strain.

Documentos Relacionados