The human pathogen Pseudomonas aeruginosa utilizes conserved virulence pathways to infect the social amoeba

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Tractable Mammalian Cell Infections with Protozoan-primed Bacteria
13:54

Tractable Mammalian Cell Infections with Protozoan-primed Bacteria

Published on: April 2, 2013

Stefan Pukatzki1, Richard H Kessin, John J Mekalanos

  • 1Department of Microbiology and Molecular Genetics, Harvard Medical School, 200 Longwood Avenue, Boston, MA 02115, USA. stefan_pukatzki@hms.harvard.edu

Proceedings of the National Academy of Sciences of the United States of America
|February 28, 2002
PubMed

Insights

Pseudomonas aeruginosa uses conserved virulence pathways to infect and kill Dictyostelium discoideum. This study identifies key bacterial genes, like lasR and exoU, essential for pathogenesis in this model system.

Area of Science:

  • Microbial Pathogenesis
  • Host-Pathogen Interactions
  • Model Organisms in Biology

Background:

  • Genetically accessible host models are crucial for understanding microbial pathogenesis.
  • Identifying pathogen evasion and disease induction mechanisms requires suitable models.

Purpose of the Study:

  • To establish and utilize a model system for studying the human pathogen Pseudomonas aeruginosa.
  • To investigate the virulence factors and pathways employed by P. aeruginosa in host infection.

Main Methods:

  • Infection of the genetically tractable eukaryote Dictyostelium discoideum by P. aeruginosa.
  • Identification of avirulent P. aeruginosa mutants through plaque assays.
  • Genetic analysis of virulence factors including lasR and type III secretion system components (PscJ, ExoU).

Main Results:

  • P. aeruginosa successfully infects and kills D. discoideum, forming intact bacterial lawns.
  • Mutants in lasR and type III secretion (PscJ, ExoU) are avirulent, forming plaques.
  • Complementation of lasR and exoU mutations restores virulence, confirming their roles.

Conclusions:

  • P. aeruginosa utilizes conserved virulence pathways, including quorum sensing (LasR) and type III secretion (ExoU), to cause disease in D. discoideum.
  • This model system effectively identifies essential virulence factors of P. aeruginosa.
  • The findings highlight conserved mechanisms of bacterial pathogenesis.

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