A comprehensive analysis of Staphylococcus aureus superantigen (SAG) genes was undertaken in isolates from a major hospital and compared with isolates from patients with toxic shock syndrome (TSS). Polymerase chain reaction (PCR) analysis included recently discovered SAGs. Staphylococcal enterotoxin (SE) G and SEI were uniquely expressed in genital isolates. Genital isolates were similar to TSS isolates, although the latter frequently expressed TSS toxin 1. Both had a high frequency of SEG/SEI and a high number of SAG genes per bacterium. Detection of an SAG gene by PCR correlated with positive results in functional assays for SAG activity. Levels of serum antibodies to SEG and SEI, but not to other superantigens, were higher in healthy women than in men and served as an independent measure of the higher frequency of exposure to SEG/SEI among women. Together, the data suggest a role for SEG/SEI or closely linked genes in the adaptation of S. aureus to the genital mucosa environment.

Staphylococcal toxic shock syndrome (TSS) is an acute life threatening disease. The diagnosis can be made clinically based on diagnostic criteria. The clinical manifestations are caused in large part by there lease of high levels of T-cell-derived cytokines as a result of potent toxins, also called superantigens (SAg), produced by Staphylococcus aureus, but it is not clear which clinical symptoms/signs are strictly T-cell dependent. Here, we report on three adults with multiple myeloma (MM) presenting with S.aureus sepsis/shock, and two patients with typical TSS. The MM patients had compromised humoral immunity because of depression of normal immunoglobulin (Ig) levels at the expense of the M protein. In addition, their T cells were absent due to high dose chemotherapy initiated for bone marrow trans-plantation. The MM cases lacked mucosal hyperemia, erythroderma and desquamation, but were otherwise indistinguishable from the TSS cases. All patients grew S. aureus and in each case, SAg genes were detected by PCR. In several cases, the plasma contained biological SAg activity resulting in VP specific proliferation of indicator T cells in vitro. The same specific activity was observed with the supernatant fluids of S. aureus broth cultures from the respective bacterial isolates. This confirms the presence of bio-active toxins in the plasma but did not lead to full blown TSS when T cells were lacking.Thus, S. aureus sepsis/shock can be clinically distinguished from typical TSS, and we suggest that mucocutaneous manifestations of TSS are the most telling signs of massive T-cell-dependent cytokine release.