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Distribution of emm genotypes and superantigen genes of Streptococcus pyogenes isolated in Japan, 1994-9

J Murakami1, S Kawabata, Y Terao

  • 1Department of Oral Microbiology, Osaka University Faculty of Dentistry, Suita-Osaka, Japan.

Epidemiology and Infection
|July 13, 2002
PubMed

Insights

This study analyzed Streptococcus pyogenes (S. pyogenes) clinical isolates in Japan. emm type distribution correlated with isolation site, while superantigen gene profiles linked to infection severity.

Area of Science:

  • Microbiology
  • Infectious Diseases
  • Genetics

Background:

  • Streptococcus pyogenes (S. pyogenes) is a significant human pathogen.
  • Understanding the genetic diversity and virulence factors of S. pyogenes is crucial for public health.
  • Previous studies have highlighted variations in emm types and superantigen genes, but their correlation with clinical presentation requires further investigation.

Purpose of the Study:

  • To investigate the characteristic profiles of S. pyogenes clinical isolates in Japan between 1994 and 1999.
  • To determine the association between M protein (emm) types, superantigen gene distribution, isolation sites, and clinical features.

Main Methods:

  • Genotyping of the M protein (emm typing) was performed on 316 S. pyogenes isolates.
  • Analysis of six superantigen genes (mf, speG, ssa, etc.) was conducted.
  • Correlation of genotypic data with isolation site and clinical presentation (invasive vs. non-invasive).

Main Results:

  • emm types 12 and 28 were the most prevalent.
  • emm12 isolates were predominantly from mucosal sites, while emm58 and emm89 were from skin.
  • emm3 isolates were more frequent in invasive infections.
  • All isolates carried the mf gene; many harbored speG.
  • The ssa gene was found more frequently in invasive isolates (76%) compared to non-invasive ones (37%).
  • Superantigen distribution varied significantly by emm type but not by isolation site.

Conclusions:

  • emm type distribution in S. pyogenes is associated with the site of isolation.
  • Superantigen gene profiles correlate with the clinical manifestations of S. pyogenes infections.
  • These findings enhance our understanding of S. pyogenes pathogenesis and epidemiology.

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