Exotoxins of Staphylococcus aureus

This article reviews the literature regarding the structure and function of two types of exotoxins expressed by Staphylococcus aureus, pyrogenic toxin superantigens (PTSAgs) and hemolysins. The molecular basis of PTSAg toxici ty is presented in the context of two diseases known to be caused by these exotoxins: toxic shock syndrome and staphylococcal food poisoning. The fami ly of staphylococcal PTSAgs presently includes toxic shock syndrome toxin-l (TSST-1) and most of the staphylococcal enterotoxins (SEs) (SEA, SEE, SEC, SED, SEE, SEG, and SEH). As the name implies, the PTSAgs air multifunction al proteins that invariably exhibit lethal activity pyrogenicity, superanti genicity, and the capacity to induce lethal hypersensitivity to endotoxin. Other properties exhibited by one or more staphylococcal PTSAgs include eme tic activity (SEs) and penetration across mucosal barriers (TSST-1). A deta iled review of the molecular mechanisms underlying the toxicity of the stap hylococcal hemolysins is also presented.