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RpiRc Is a Pleiotropic Effector of Virulence Determinant Synthesis and Attenuates Pathogenicity in Staphylococcus

Rosmarie Gaupp1,2, Jessica Wirf3, B Wonnenberg4

  • 1Institute of Medical Microbiology and Hygiene, Saarland University Medical Center, Homburg/Saar, Germany rosmarie.gaupp@uks.eu.

Infection and Immunity
|April 27, 2016
PubMed

Insights

This study reveals that Staphylococcus aureus regulator RpiRc, alongside metabolic status and other regulators like σ(B) and SarA, negatively impacts virulence factor production and bacterial infection.

Area of Science:

  • Microbiology
  • Molecular Biology
  • Bacterial Pathogenesis

Background:

  • Metabolism and virulence are linked in Staphylococcus aureus via metabolite-responsive regulators.
  • Staphylococcus aureus has three RpiR family transcriptional regulators, including RpiRc, which influences the pentose phosphate pathway and RNAIII levels.
  • RNAIII is a key regulatory RNA for the agr quorum-sensing system, controlling virulence determinant synthesis.

Purpose of the Study:

  • To investigate the role of RpiRc in regulating RNAIII transcription and virulence in Staphylococcus aureus.
  • To identify other regulators that mediate the connection between RpiRc and RNAIII.
  • To understand how RpiRc interacts with other known regulators (SarA, SigB, MgrA, AcnA) and bacterial metabolic state in controlling virulence.

Main Methods:

  • Generated single and double mutants of Staphylococcus aureus, including an rpiRc mutant combined with sarA, sigB, mgrA, and acnA mutations.
  • Assessed the effects of these mutations on RNAIII levels.
  • Analyzed phenotypic and genotypic differences in mutant strains.
  • Evaluated the virulence of selected strains in murine infection models.

Main Results:

  • RpiRc influences RNAIII transcription and virulence determinant synthesis.
  • The effects of RpiRc are exerted in conjunction with σ(B) (sigma B), SarA, and the bacterial metabolic status.
  • These combined factors negatively impact Staphylococcus aureus virulence.

Conclusions:

  • RpiRc plays a significant role in modulating Staphylococcus aureus virulence.
  • RpiRc acts in concert with other regulatory systems and metabolic conditions to control virulence factor expression.
  • The findings elucidate a complex regulatory network linking metabolism, transcription, and pathogenesis in Staphylococcus aureus.

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