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The alternative sigma factor sigma B of Staphylococcus aureus modulates virulence in experimental central venous

Udo Lorenz1, Christian Hüttinger, Tina Schäfer

  • 1University of Würzburg, Centre for Operative Medicine, Department of Surgery I, Oberdürrbacher Str. 6, 97080 Würzburg, Germany.

Microbes and Infection
|March 11, 2008
PubMed

Insights

The alternative sigma factor sigma B (SigB) significantly impacts Staphylococcus aureus virulence in central venous catheter infections. SigB deficiency reduces S. aureus pathogenicity, though biofilm formation remains unaffected.

Area of Science:

  • Microbiology
  • Infectious Diseases
  • Bacterial Pathogenesis

Background:

  • The role of alternative sigma factors in bacterial virulence is crucial but not fully understood.
  • Staphylococcus aureus is a common cause of central venous catheter (CVC)-related infections.
  • Sigma B (SigB) is an alternative sigma factor in S. aureus with an unclear impact on pathogenesis.

Purpose of the Study:

  • To investigate the role of SigB in the pathogenesis of S. aureus infections.
  • To assess the influence of SigB on biofilm formation in vivo during CVC-related infections.
  • To determine the contribution of SigB to the virulence of S. aureus in a multiorgan infection model.

Main Methods:

  • Utilized a central venous catheter (CVC) related multiorgan infection model.
  • Compared SigB-positive wild-type S. aureus strains with their isogenic SigB-deficient mutants.
  • Analyzed bacterial virulence and in vivo biofilm formation within the catheter.

Main Results:

  • Wild-type S. aureus strains demonstrated significantly higher virulence compared to SigB-deficient mutants.
  • Both wild-type and mutant strains were capable of forming biofilms inside the CVC.
  • The difference in virulence was not attributable to variations in biofilm formation capacity.

Conclusions:

  • The alternative sigma factor SigB plays a significant role in the pathogenesis of S. aureus.
  • SigB is important for S. aureus virulence in the context of CVC-associated infections.
  • Further research into SigB's regulatory mechanisms in S. aureus pathogenesis is warranted.

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