A CLINICAL AND BACTERIOLOGICAL INVESTIGATION OF INVASIVE STREPTOCOCCAL INFECTIONS IN JAPAN ON THE BASIS OF SEROTYPES, TOXIN PRODUCTION, ANDGENOMIC DNA FINGERPRINTS

In a survey of invasive streptococcal infections in Japan, we analyzed isolates of Streptococcus pyogenes collected between 1992 and 1994, G enomic DNA fingerprints produced by pulsed-field gel electrophoresis ( PFGE) were compared by computer-assisted analysis, Conventional serolo gic M types were subdivided into PFGE types showing close genetic simi larity, Among the 42 isolates from patients with invasive diseases, 16 PFGE types were identified and genetic diversity was clearly demonstr ated, Identical fingerprints were observed in both invasive and noninv asive isolates, Only 43% of invasive isolates produced streptococcal p yrogenic exotoxin A (SPE A), and 31% did not contain the speA gene. Th ese findings suggest that the dissemination of a specific clone is not sufficient to explain all cases of these diseases in Japan and pose a question as to the role of SPE A as a major virulent factor, Bacteria l factors other than SPE A and host factors should be considered in ev aluation of the pathogenesis of the diseases.