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Invasion of Human Cells by a Bacterial Pathogen
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Group A streptococcal rofA gene is involved in the control of several virulence genes and eukaryotic cell attachment

S Beckert1, B Kreikemeyer, A Podbielski

  • 1Department of Medical Microbiology, University Hospital Ulm, D-89081 Ulm, Germany.

Infection and Immunity
|December 19, 2000
PubMed

Insights

The RofA regulator in Group A Streptococcus M6 influences virulence. A mutant lacking RofA showed decreased expression of key virulence genes and reduced bacterial invasion and host cell damage.

Area of Science:

  • Microbiology
  • Molecular Biology
  • Streptococcal Pathogenesis

Background:

  • Group A Streptococcus (GAS) M6 serotype utilizes the RofA regulator.
  • RofA positively controls Protein F1 and fibronectin binding.

Purpose of the Study:

  • Investigate the indirect effects of the RofA regulator on GAS virulence gene expression.
  • Determine the role of RofA in bacterial invasion and host cell interaction.

Main Methods:

  • Construction and analysis of a serotype M6 *rofA* mutant.
  • Quantitative assessment of virulence gene expression (mga, emm6, pel-sagA, speA).
  • Measurement of bacterial internalization rates and host cell viability assays.

Main Results:

  • The *rofA* mutant displayed reduced expression of mga, emm6, pel-sagA, and speA virulence genes.
  • Internalization of the *rofA* mutant into eukaryotic cells was significantly decreased.
  • Host cell viability was reduced in the presence of the *rofA* mutant.

Conclusions:

  • The RofA regulator exerts an indirect negative influence on multiple GAS virulence factors.
  • RofA plays a critical role in bacterial invasion and pathogenesis, impacting host cell integrity.

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