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Establishment of a High-throughput Setup for Screening Small Molecules That Modulate c-di-GMP Signaling in Pseudomonas aeruginosa
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Establishment of a High-throughput Setup for Screening Small Molecules That Modulate c-di-GMP Signaling in Pseudomonas aeruginosa

Published on: June 30, 2016

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CmpX Affects Virulence in Pseudomonas aeruginosa Through the Gac/Rsm Signaling Pathway and by Modulating c-di-GMP

Anjali Y Bhagirath1, Deepti Somayajula1, Yanqi Li1

  • 1Department of Oral Biology, Rady Faculty of Health Sciences, College of Dentistry, Biology of Breathing Group, Children's Hospital Research Institute of Manitoba, University of Manitoba, Winnipeg, MB, R3E 0W2, Canada.

The Journal of Membrane Biology
|October 25, 2017
PubMed

Insights

The study reveals that the protein CmpX regulates virulence and biofilm formation in Pseudomonas aeruginosa by influencing the Gac/Rsm pathway and intracellular cyclic-di-GMP levels. This impacts antibiotic resistance and host colonization.

Area of Science:

  • Microbiology
  • Molecular Biology
  • Bacterial Pathogenesis

Background:

  • Pseudomonas aeruginosa is a versatile pathogen causing chronic infections through biofilm formation.
  • Virulence and biofilm regulation involve complex signaling pathways, including the Gac/Rsm system and cyclic-di-GMP (c-di-GMP).
  • The protein CmpX (PA1775) was previously identified as a regulator of the PA1611 pathway.

Purpose of the Study:

  • To investigate the role of CmpX in regulating virulence and biofilm formation in P. aeruginosa.
  • To elucidate the mechanism by which CmpX affects the Gac/Rsm pathway and intracellular c-di-GMP levels.
  • To assess the impact of CmpX on bacterial gene expression and susceptibility to environmental stressors.

Main Methods:

  • Construction and analysis of a cmpX knockout mutant in P. aeruginosa.
  • Measurement of promoter activities (exoS, RsmY), intracellular c-di-GMP levels (via cdrA activity), and gene expression (oprF, sigX).
  • Phenotypic characterization using Biolog phenotype microarrays to assess sensitivity to detergents and antibiotics.

Main Results:

  • CmpX regulates virulence and biofilm formation, affecting the Gac/Rsm pathway and modulating intracellular c-di-GMP.
  • A cmpX knockout mutant exhibited decreased exoS promoter activity, increased RsmY activity, and elevated c-di-GMP levels.
  • The mutant showed decreased expression of oprF and sigX, and increased sensitivity to membrane detergents and antibiotics (tobramycin, vancomycin).

Conclusions:

  • CmpX plays a significant role in P. aeruginosa virulence and colonization.
  • CmpX influences bacterial physiology by modulating c-di-GMP levels and affecting the Gac/Rsm signaling pathway.
  • Disruption of CmpX function leads to altered gene expression and increased susceptibility to antibiotics, highlighting its importance in pathogenesis.
Keywords:
BiofilmPhenotype microarraysPseudomonas aeruginosac-di-GMPcmpX

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