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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.

Neonatal toxic shock syndrome-like exanthematous disease (NTED) is a new neonatal disease caused by toxic shock syndrome toxin 1 (TSST-1). We conducted a prospective surveillance study and characterized the methicillin-resistant Staphylococcus aureus (MRSA) strains isolated from patients with NTED and compared them with the strains from patients with other MRSA infections and asymptomatic carriers. The study was performed in the neonatal intensive care unit and a general neonatal and maternal ward in the Tokyo Women's Medical University Hospital (TWMUH) from September to December 1998. Among 103 patients eligible for the study, MRSA was detected in 62 (60.2%) newborns; of these 62 newborns, 8 (12.9%) developed NTED, 1 (1.6%) had another MRSA infection, and 53 (85.5%) were asymptomatic MRSA carriers. Sixty-nine MRSA strains were obtained from the 62 newborns. DNA fingerprinting by pulsed-field gel electrophoresis showed two clusters: clone A with 8 subtypes and clone B. Sixty-seven of the 69 MRSA strains (97.1%) belonged to clone A, and type A1 was the most predominant (42 of 69 strains; 60.9%) in every neonatal and perinatal ward. All but one of the clone A strains had the TSST-1 and staphylococcal enterotoxin C genes. We also analyzed eight MRSA strains from eight NTED patients in five hospitals in Japan other than TWMUH. All the MRSA strains from NTED patients also belonged to clone A. These results suggest that a single clone that predominated in the neonatal wards of six hospitals might have caused NTED. However, the occurrence of NTED might not be dependent on the presence of an NTED-specific strain.

The purpose of this study was to examine the suitability of fibronectin-binding protein FBP54 as a putative vaccine for Streptococcus pyogenes infections. When the distribution of the fbp54 gene among the clinical isolates representing various M serotypes was tested by PCR and Southern blot assays, it was found that all of the strains possess this gene. Furthermore, a significant increase in immunoglobulin G (IgG) antibody titers against FBP54 was observed in sera from patients with S. pyogenes infections compared with those from healthy volunteers (P < 0.005). Mice were immunized with FBP54 subcutaneously, orally, or nasally. An enzyme-linked immunosorbent assay revealed that antigen-specific IgG antibodies were induced in the sera of immunized mice, while high salivary levels of IgA antibodies were detected after oral and nasal immunizations. Mice subcutaneously or orally immunized with FBP54 survived significantly longer following the challenge with S. pyogenes than did nonimmunized mice (P < 0.001). These results indicate that FBP54 is a promising vaccine for the prevention of S. pyogenes infections.