Prevalence of toxic shock syndrome toxin 1 (TSST-1)-producing strains of Staphylococcus aureus and antibody to TSST-1 among healthy Japanese women

Abstract

Many cases of neonatal toxic shock syndrome (TSS)-like exanthematous disease but few cases of menstrual TSS (mTSS) have been reported in Japan. We determined the prevalence of mucosal colonization with Staphylococcus aureus and of positive antibodies to TSS toxin 1 (TSST-1) among 209 healthy Japanese women in Tokyo. S. aureus isolates from mucosal sites were characterized with respect to TSST-1 production and resistance genotype. Antibody titers were determined for test subjects and for 133 Japanese and 137 Caucasian control women living in the United States. S. aureus was isolated from at least one site in 108 of 209 women (52%) in Tokyo. Of the 159 S. aureus isolates recovered, 14 (9%) were TSST-1 positive (12 unique strains). Twelve of 209 women (6%) were colonized with a TSST-1-producing strain; two (<1%) had vaginal colonization. Only 2 of 12 unique toxigenic strains (14%) were methicillin resistant. Of the 12 TSST-1-positive strains isolated, 6 (50%) were pulsed-field gel electrophoresis type USA200, multilocus sequence type clonal complex 30. Fewer Japanese women in Tokyo (47%) than Caucasian and Japanese women in the United States (89% and 75%, respectively) had TSST-1 antibodies. The prevalences of colonization with TSST-1-producing S. aureus were comparable in Japan and the United States, despite low seropositivity to TSST-1 in Japan. Environmental factors appear to be important in promoting the development of anti-TSST-1 antibodies, as there was a significant difference in titers between Japanese women living in Tokyo and those living in the United States. Most colonizing TSST-1-producing S. aureus strains in Japan were genotypically similar to mTSS strains found in the United States.

FIG. 1.

Logistic regression results: the probability of being seropositive for anti-TSST-1 antibodies versus the age of Japanese women in Tokyo and control women of Caucasian and Japanese ancestry in the United States. P values for age were 0.002 (Japanese women in Tokyo), 0.315 (Japanese women in the United States), and 0.465 (Caucasian women in the United States).

FIG. 2.

Titers of anti-TSST-1 antibodies in Japanese women in Tokyo and in control women of Caucasian and Japanese ancestry living in the United States.

FIG. 3.

PFGE macrorestriction analysis of the 14 TSST-1-producing isolates cultured during the study. Angle brackets indicate isolates with indistinguishable PFGE patterns from the same subject. Methicillin-resistant isolates are indicated by an asterisk.

FIG. 4.

Titers of anti-TSST-1 antibodies in Japanese women in Tokyo and Japanese women colonized with TSST-1-producing S. aureus.