Pseudomonas aeruginosa eradicates Staphylococcus aureus by manipulating the host immunity

Nat Commun. 2014 Oct 7;5:5105. doi: 10.1038/ncomms6105.

Abstract

Young cystic fibrosis (CF) patients' airways are mainly colonized by Staphylococcus aureus, while Pseudomonas aeruginosa predominates in adults. However, the mechanisms behind this infection switch are unclear. Here, we show that levels of type-IIA-secreted phospholipase A2 (sPLA2-IIA, a host enzyme with bactericidal activity) increase in expectorations of CF patients in an age-dependent manner. These levels are sufficient to kill S. aureus, with marginal effects on P. aeruginosa strains. P. aeruginosa laboratory strains and isolates from CF patients induce sPLA2-IIA expression in bronchial epithelial cells from CF patients (these cells are a major source of the enzyme). In an animal model of lung infection, P. aeruginosa induces sPLA2-IIA production that favours S. aureus killing. We suggest that sPLA2-IIA induction by P. aeruginosa contributes to S. aureus eradication in CF airways. Our results indicate that a bacterium can eradicate another bacterium by manipulating the host immunity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • ADP Ribose Transferases
  • Adolescent
  • Adult
  • Animals
  • Bacterial Toxins
  • Bronchi
  • Child
  • Child, Preschool
  • Cystic Fibrosis / enzymology
  • Cystic Fibrosis / microbiology*
  • Disease Progression
  • Epithelial Cells / enzymology*
  • Group II Phospholipases A2 / metabolism*
  • Guinea Pigs
  • Humans
  • Mice
  • Pseudomonas aeruginosa / physiology*
  • Respiratory Mucosa
  • Sputum / enzymology*
  • Staphylococcus aureus / physiology*
  • Young Adult

Substances

  • Bacterial Toxins
  • ADP Ribose Transferases
  • exoenzyme S
  • Group II Phospholipases A2
  • PLA2G2A protein, human