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Characterization of a novel two-partner secretion system implicated in the virulence of Pseudomonas aeruginosa

Laura M Faure1, Steve Garvis1, Sophie de Bentzmann1

  • 1UMR7255, CNRS - Aix Marseille Université, 31 Chemin Joseph Aiguier, 13402 Marseille, France.

Microbiology (Reading, England)
|July 11, 2014
PubMed

Insights

Pseudomonas aeruginosa virulence involves a two-partner secretion (TPS) system. A functional TPS system, PdtA and PdtB, is crucial for P. aeruginosa pathogenesis and infection.

Area of Science:

  • Microbiology
  • Pathogenesis
  • Molecular Biology

Background:

  • Pseudomonas aeruginosa is an opportunistic pathogen causing hospital-acquired infections.
  • Its virulence mechanisms are not fully understood, especially in immunocompromised individuals like cystic fibrosis patients.

Purpose of the Study:

  • To identify and characterize novel virulence factors in P. aeruginosa.
  • To investigate the role of a specific two-partner secretion (TPS) system in P. aeruginosa pathogenesis.

Main Methods:

  • Identification of a novel two-partner secretion (TPS) system (PdtA exoprotein and PdtB transporter).
  • Analysis of PdtA protein production under inorganic phosphate (Pi) limitation.
  • Demonstration of PdtA processing during outer-membrane translocation.
  • Assessment of PdtA transport dependency on PdtB.
  • Virulence testing using a Caenorhabditis elegans infection model.

Main Results:

  • A functional TPS system, PdtA and PdtB, was identified and implicated in P. aeruginosa virulence.
  • PdtA production is induced by inorganic phosphate (Pi) limitation.
  • PdtA undergoes N-terminal extracellular release and C-terminal outer membrane association.
  • PdtA transport is dependent on PdtB, confirming a functional TPS system.
  • A pdtA mutant exhibited reduced virulence in a C. elegans infection model.

Conclusions:

  • The PdtA/PdtB TPS system is a novel virulence factor for Pseudomonas aeruginosa.
  • This system plays a significant role in P. aeruginosa pathogenesis, particularly under nutrient-limited conditions.
  • Targeting this TPS system could offer new strategies for combating P. aeruginosa infections.

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