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MarA, SoxS and Rob function as virulence factors in an Escherichia coli murine model of ascending pyelonephritis

Paul Casaz1, Lynne K Garrity-Ryan1, David McKenney1

  • 1Paratek Pharmaceuticals, Inc., 75 Kneeland Street, Boston, MA 02111, USA.

Microbiology (Reading, England)
|December 13, 2006
PubMed

Insights

MarA, SoxS, and Rob transcription factors are crucial for Escherichia coli virulence in urinary tract infections. Deleting these factors significantly reduces bacterial infection severity in a mouse model.

Area of Science:

  • Microbiology and Molecular Biology
  • Bacterial Pathogenesis and Virulence Factors
  • Genetics and Gene Regulation

Background:

  • MarA, SoxS, and Rob are AraC family transcription factors historically linked to antibiotic resistance and stress tolerance.
  • Limited experimental data exist regarding their role in bacterial virulence regulation.

Purpose of the Study:

  • To investigate the role of MarA, SoxS, and Rob transcription factors in the virulence of *Escherichia coli*.
  • To assess the contribution of these factors in a clinically relevant model of urinary tract infection.

Main Methods:

  • Utilized a murine model of ascending pyelonephritis to study *E. coli* virulence.
  • Compared virulence of clinical isolates with isogenic strains lacking individual or all three transcription factors (marA, soxS, rob).
  • Performed complementation studies to confirm the role of each transcription factor.

Main Results:

  • Triple knockout strains lacking MarA, SoxS, and Rob were significantly less virulent than parental strains.
  • Complementation with individual factors restored wild-type virulence in the triple knockout.
  • Deletion of soxS or rob alone had a more detrimental effect on virulence than marA deletion.

Conclusions:

  • MarA, SoxS, and Rob transcription factors collectively contribute to *E. coli* virulence in vivo.
  • These factors play a significant role in the pathogenesis of urinary tract infections.

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