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Using a Bacterial Pathogen to Probe for Cellular and Organismic-level Host Responses
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Using a Bacterial Pathogen to Probe for Cellular and Organismic-level Host Responses

Published on: February 22, 2019

H(2)O(2)-nonproducing Streptococcus pyogenes strains: survival in stationary phase and virulence in chronic

Mitsumasa Saito1, Shouichi Ohga1, Miyoko Endoh2

  • 1Departments of Bacteriology1 and Pediatrics2, Faculty of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.

Microbiology (Reading, England)
|September 6, 2001
PubMed

Insights

Hydrogen peroxide (H2O2) production varies in Streptococcus pyogenes. Non-producing strains are more virulent in mice and pose a threat to patients with chronic granulomatous disease (CGD).

Area of Science:

  • Microbiology
  • Immunology
  • Pathogen Biology

Background:

  • Streptococcus pyogenes causes pharyngitis and severe infections.
  • Hydrogen peroxide (H2O2) production is a phenotype studied in S. pyogenes.
  • The role of H2O2 in S. pyogenes virulence and host interaction is not fully understood.

Purpose of the Study:

  • To investigate H2O2 production in S. pyogenes strains from different infection types.
  • To determine the impact of H2O2 production on S. pyogenes virulence and survival.
  • To assess the susceptibility of H2O2-producing and non-producing strains to phagocyte killing, particularly in the context of chronic granulomatous disease (CGD).

Main Methods:

  • Isolation and characterization of S. pyogenes strains from pharyngitis and severe infections.
  • Culturing strains under specific conditions to measure H2O2 accumulation.
  • Assessing cell viability and the role of H2O2 in lethality using catalase.
  • Evaluating resistance to phagocyte killing from CGD patients.
  • Inoculating CGD mice with different S. pyogenes strains to assess virulence and mortality.

Main Results:

  • 25 out of 46 S. pyogenes strains accumulated H2O2 under glucose-limited, aerobic conditions.
  • H2O2 accumulation correlated with a loss of cell viability, preventable by catalase.
  • H2O2-nonproducing strains showed resistance to CGD phagocyte killing.
  • In CGD mice, H2O2-nonproducing strains caused more severe footpad swelling and higher mortality rates.
  • No correlation was found between H2O2 production and disease type or T type.

Conclusions:

  • H2O2-nonproducing S. pyogenes strains are prevalent and may pose a significant health risk to individuals with CGD.
  • H2O2 production influences S. pyogenes virulence and interaction with the host immune system.
  • Understanding these phenotypes is crucial for managing S. pyogenes infections, especially in immunocompromised individuals.

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