Structure and function of streptococcal and staphylococcal superantigens in septic shock.

The pyrogenic exotoxins of Group A Streptococci and enterotoxins of Staphylococcus aureus constitute a family of related toxins that acts as "superantigens" because of their ability to stimulate large numbers of T-cell subsets. These toxins have been implicated in gastrointestinal food poisoning, toxic shock syndromes, Gram-positive sepsis, and, possibly, septic shock. There is increasing evidence that Gram-positive infections frequently coexist in septic shock and that bacterial superantigens play a major role.