We investigated the involvement of the recently described staphylococcal 
enterotoxins G and I in toxic shock syndrome. We reexamined Staphylococcus 
aureus strains isolated from patients with menstrual and nonmenstrual toxic 
shock syndrome (nine cases) or staphylococcal scarlet fever (three cases). These 
strains were selected because they produced none of the toxins known to be 
involved in these syndromes (toxic shock syndrome toxin 1 and enterotoxins A, B, 
C, and D), enterotoxin E or H, or exfoliative toxin A or B, despite the fact 
that superantigenic toxins were detected in a CD69-specific flow cytometry assay 
measuring T-cell activation. Sets of primers specific to the enterotoxin G and I 
genes (seg and sei, respectively) were designed and used for PCR amplification. 
All of the strains were positive for seg and sei. Sequence analysis confirmed 
that the PCR products, corresponded to the target genes. We suggest that 
staphylococcal enterotoxins G and I may be capable of causing human 
staphylococcal toxic shock syndrome and staphylococcal scarlet fever.