Pyrogenic specificity of streptococcal exotoxins, staphylococcal enterotoxin, and gram-negative endotoxin.

Streptococcal exotoxin and staphylococcal enterotoxin share several biological properties, including pyrogenicity, lymphocyte mitogenicity, and enhancement of gram-negative endotoxin lethality. These analogies of the toxins prompted comparative pyrogenic studies. When American Dutch rabbits were immunized by repeated intravenous injections of small amounts of staphylococcal enterotoxin, they exhibited a decreased febrile response upon challenge when compared with control animals not previously injected. The same animals responded similarly to control groups when challenged with streptococcal exotoxin A, B, or C. No cross-reactivity was observed in reciprocal cross-tests, using animals immune to the streptococcal toxins and challenging with staphylococcal enterotoxin. No cross-reactivity between either the streptococcal or staphylococcal toxins and bacterial endotoxin was observed.