The Lon Protease Is Essential for Full Virulence in Pseudomonas aeruginosa

Elena B.M. Breidenstein, Laure Janot, Janine Strehmel, Lucia Fernandez, Patrick K. Taylor, Irena Kukavica-Ibrulj, Shaan L. Gellatly, Roger C. Levesque, Joerg Overhage, Robert Hancock

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Pseudomonas aeruginosa PAO1 lon mutants are supersusceptible to ciprofloxacin, and exhibit a defect in cell division and in virulence-related properties, such as swarming, twitching and biofilm formation, despite the fact that the Lon protease is not a traditional regulator. Here we set out to investigate the influence of a lon mutation in a series of infection models. It was demonstrated that the lon mutant had a defect in cytotoxicity towards epithelial cells, was less virulent in an amoeba model as well as a mouse acute lung infection model, and impacted on in vivo survival in a rat model of chronic infection. Using qRT-PCR it was demonstrated that the lon mutation led to a down-regulation of Type III secretion genes. The Lon protease also influenced motility and biofilm formation in a mucin-rich environment. Thus alterations in several virulence-related processes in vitro in a lon mutant were reflected by defective virulence in vivo.

Original languageEnglish
Article numbere49123
JournalPLoS ONE
Issue number11
Publication statusPublished - 7 Nov 2012
Externally publishedYes

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)
  • Agricultural and Biological Sciences(all)
  • General

Cite this

Breidenstein, E. B. M., Janot, L., Strehmel, J., Fernandez, L., Taylor, P. K., Kukavica-Ibrulj, I., ... Hancock, R. (2012). The Lon Protease Is Essential for Full Virulence in Pseudomonas aeruginosa. PLoS ONE, 7(11), [e49123].