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Detection of invasive protein profile of Streptococcus pyogenes M1 isolates from pharyngitis patients

Tadao Hasegawa1, Akira Okamoto, Takuya Kamimura

  • 1Department of Bacteriology, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Nagoya, Japan. tadaoh@med.nagoya-cu.ac.jp

APMIS : Acta Pathologica, Microbiologica, Et Immunologica Scandinavica
|February 6, 2010
PubMed

Insights

Mutations in the covS gene of Streptococcus pyogenes M1 isolates are linked to Streptococcal toxic shock syndrome (STSS). These covS mutations, impairing protein function, were also found in pharyngitis cases, suggesting broader implications for M1 Streptococcus pyogenes infections.

Area of Science:

  • Microbiology
  • Infectious Diseases
  • Genetics

Background:

  • Streptococcal toxic shock syndrome (STSS) is a re-emerging disease, with the M1 serotype of Streptococcus pyogenes being a primary cause.
  • Mutations in the covS gene, a two-component regulatory system, are implicated in STSS by affecting protein expression.

Purpose of the Study:

  • To analyze M1 Streptococcus pyogenes clinical isolates from Japan before and after 1990 to understand the genetic changes associated with STSS.
  • To investigate the role of covS mutations in both STSS and pharyngitis isolates.

Main Methods:

  • Utilized two-dimensional gel electrophoresis (2-DE) and pulsed-field gel electrophoresis (PFGE) to analyze M1 S. pyogenes isolates.
  • Conducted sequence analysis of two-component regulatory systems, focusing on covS mutations.
  • Assessed the functional impact of mutated CovS on streptococcal pyrogenic exotoxin B (SpeB) production using 2-DE.

Main Results:

  • Distinct PFGE profiles were observed between isolates from before and after 1990, and between STSS and pharyngitis isolates post-1990.
  • covS mutations were identified in both STSS and pharyngitis isolates.
  • Mutated CovS in pharyngitis isolates showed impaired function in SpeB production, indicating an invasive protein profile.

Conclusions:

  • covS mutations are present in M1 Streptococcus pyogenes isolates causing STSS and pharyngitis.
  • These mutations can lead to the malfunction of the CovS protein, affecting virulence factor production even in non-STSS infections like pharyngitis.

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