Detection of N-acylhomoserine lactones in lung tissues of mice infected with Pseudomonas aeruginosa

Microbiology. 2000 Oct;146 ( Pt 10):2481-2493. doi: 10.1099/00221287-146-10-2481.

Abstract

The pathogenesis of Pseudomonas aeruginosa is associated with expression of virulence factors, many of which are controlled by two N:-acylhomoserine lactone (AHL)-based quorum-sensing systems. Escherichia coli strains equipped with a luxR-based monitor system expressing green fluorescent protein (GFP) in the presence of exogenous AHL molecules were used to detect the production of AHLs from P. aeruginosa in vivo. Mice were challenged intratracheally with alginate beads containing P. aeruginosa and E. coli and killed on different days after the challenge. By means of confocal scanning laser microscopy, GFP-expressing E. coli bacteria could be detected in the lung tissues, indicating production and excretion of AHL molecules in vivo by the infecting P. aeruginosa. AHL signals were detected mainly in lung tissues exhibiting severe pathological changes. These findings support the view that expression of AHL molecules by P. aeruginosa during infection coincides with its pathogenesis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 4-Butyrolactone / analogs & derivatives*
  • 4-Butyrolactone / genetics
  • 4-Butyrolactone / metabolism*
  • Animals
  • Cystic Fibrosis / microbiology
  • Disease Models, Animal
  • Gene Expression Regulation, Bacterial
  • Green Fluorescent Proteins
  • Humans
  • Luminescent Proteins / genetics
  • Luminescent Proteins / metabolism
  • Lung / metabolism*
  • Lung / microbiology*
  • Lung / pathology
  • Mice
  • Mice, Inbred CBA
  • Pseudomonas Infections / metabolism
  • Pseudomonas Infections / microbiology*
  • Pseudomonas Infections / pathology
  • Pseudomonas aeruginosa / genetics
  • Pseudomonas aeruginosa / metabolism
  • Pseudomonas aeruginosa / pathogenicity*
  • Signal Transduction

Substances

  • Luminescent Proteins
  • homoserine lactone
  • Green Fluorescent Proteins
  • 4-Butyrolactone