The sensor kinase PhoQ mediates virulence in Pseudomonas aeruginosa

Microbiology. 2009 Mar;155(Pt 3):699-711. doi: 10.1099/mic.0.024554-0.


Pseudomonas aeruginosa is a ubiquitous environmental Gram-negative bacterium that is also a major opportunistic human pathogen in nosocomial infections and cystic fibrosis chronic lung infections. PhoP-PhoQ is a two-component regulatory system that has been identified as essential for virulence and cationic antimicrobial peptide resistance in several other Gram-negative bacteria. This study demonstrated that mutation of phoQ caused reduced twitching motility, biofilm formation and rapid attachment to surfaces, 2.2-fold reduced cytotoxicity to human lung epithelial cells, substantially reduced lettuce leaf virulence, and a major, 10 000-fold reduction in competitiveness in chronic rat lung infections. Microarray analysis revealed that PhoQ controlled the expression of many genes consistent with these phenotypes and with its known role in polymyxin B resistance. It was also demonstrated that PhoQ controls the expression of many genes outside the known PhoP regulon.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism*
  • Biofilms
  • Cell Line, Transformed
  • Gene Expression Regulation, Bacterial
  • Humans
  • Male
  • Microbial Sensitivity Tests
  • Mutation
  • Oligonucleotide Array Sequence Analysis
  • Phosphotransferases / genetics
  • Phosphotransferases / metabolism*
  • Polymyxin B / metabolism
  • Pseudomonas Infections / microbiology
  • Pseudomonas aeruginosa / genetics*
  • Pseudomonas aeruginosa / metabolism
  • Pseudomonas aeruginosa / pathogenicity*
  • RNA, Bacterial / genetics
  • Rats
  • Rats, Sprague-Dawley
  • Regulon
  • Sequence Analysis, DNA
  • Virulence


  • Bacterial Proteins
  • PhoQ protein, Bacteria
  • RNA, Bacterial
  • Phosphotransferases
  • Polymyxin B