Prevalence of the speA2 and speA3 alleles in Streptococcus pyogenes isolated from TSLS patients in Japan

More than 100 cases have been identified as streptococcal toxic shock-like syndrome (TSLS) in Japan, since the first case was reported in 1993. Of 26 S. pyogenes isolates associated with TSLS, 69% were M-types 1 and 3. This study focused on speA alleles which were carried by all M-type 1 and 3 isolates and isolates of some other M-types, irrespective of sources. We sequenced the nucleotides of the relevant region of the speA allele in all of these isolates. Consistent with other reports, these M-type 1 and 3 isolates carried the speA2 and speA3 alleles, respectively. Our results indicate that these two speA alleles, which were prevalent world-wide have been disseminating in Japan.