Pseudomonas aeruginosa eradicates Staphylococcus aureus by manipulating the host immunity

Erwan Pernet (1, 2) , Laurent Guillemot (1) , Pierre-Régis Burgel (3, 4) , Clémence Martin (3, 4) , Gérard Lambeau (5) , Isabelle Sermet-Gaudelus (6, 7) , Dorota Sands (8) , Dominique Leduc (1) , Philippe Morand (3, 9) , Louise Jeammet (5) , Michel Chignard (1) , Yongzheng Wu (1) , Lhousseine Touqui (1)

1 Défense innée et inflammation
2 Cellule Pasteur UPMC
3 UPD5 - Université Paris Descartes - Paris 5
4 Service de pneumologie [CHU Cochin]
5 IPMC - Institut de pharmacologie moléculaire et cellulaire
6 Service de Pneumologie et d'Allergologie Pédiatriques
7 UMR_S 806 - Régulation du transport anionique transépithélial : de la recherche fondamentale aux pathologies épithéliales
8 National Research Institute of Mother and Child [Warsaw, Poland]
9 Service de Bactériologie [CHU Cochin, AP-HP]

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.

Keywords: Bacterial infection; Respiratory tract diseases

Domains: Life Sciences [q-bio]; Immunology; Innate immunity; Life Sciences [q-bio]; Human health and pathology; Infectious diseases; Life Sciences [q-bio]; Microbiology and Parasitology; Bacteriology

Erwan Pernet, Laurent Guillemot, Pierre-Régis Burgel, Clémence Martin, Gérard Lambeau, et al.. Pseudomonas aeruginosa eradicates Staphylococcus aureus by manipulating the host immunity. Nature Communications, 2014, 5 (1), pp.5105. ⟨10.1038/ncomms6105⟩. ⟨pasteur-02863033⟩