Objective: The prevalence and characteristics of S. aureus strains producing toxic shock syndrome toxin-1 (TSST-1) vary depending on population demographics and geography. This study evaluated the prevalence of mucosal colonization with S. aureus and anti-TSST-1 Ab in healthy Japanese women.
Methods: 209 subjects, ages 18 to 45, were surveyed. S. aureus isolates were screened for methicillin-resistance and TSST-1. TSST-1-positive isolates were further characterized molecularly. TSST-1 Ab titers were determined for test subjects as well as 133 ethnic Japanese and 137 Caucasian control subjects living in the US.
Results: S. aureus colonization at any body site was demonstrated in 52% of subjects. 6% of women were colonized with toxigenic S. aureus (< 1% vaginally) with 9% of all S. aureus isolates TSST-1 positive. Only 2 of 12 toxigenic strains were MRSA, one USA300 and the other typical of Japanese isolates associated with neonatal TSS-like exanthematous disease (NTED). 50% of TSST-1-positive isolates were similar to the predominant TSST-1-positive S. aureus genotype in the U.S. Prevalence of positive TSST-1 Ab (titer ≥ 1:32) in US Caucasian subjects was higher (89%) than among US Japanese subjects (75%) or Tokyo subjects (47%).
Conclusion: Carriage of TSST-1-positive S. aureus (and methicillin resistance plus TSST-1) was uncommon. Most TSST-1-positive S. aureus isolates were genetically similar to those in the U.S. Colonization with TSST-1-producing S. aureus in Japan appeared comparable to the US, despite the relatively low rate of seropositivity.