The role of multispecies social interactions in shaping Pseudomonas aeruginosa pathogenicity in the cystic fibrosis lung

Abstract

Pseudomonas aeruginosa is a major pathogen in the lungs of cystic fibrosis (CF) patients. However, it is now recognised that a diverse microbial community exists in the airways comprising aerobic and anaerobic bacteria as well as fungi and viruses. This rich soup of microorganisms provides ample opportunity for interspecies interactions, particularly when considering secreted compounds. Here, we discuss how P. aeruginosa-secreted products can have community-wide effects, with the potential to ultimately shape microbial community dynamics within the lung. We focus on three well-studied traits associated with worsening clinical outcome in CF: phenazines, siderophores and biofilm formation, and discuss how secretions can shape interactions between P. aeruginosa and other commonly encountered members of the lung microbiome: Staphylococcus aureus, the Burkholderia cepacia complex, Candida albicans and Aspergillus fumigatus. These interactions may shape the evolutionary trajectory of P. aeruginosa while providing new opportunities for therapeutic exploitation of the CF lung microbiome.

Keywords: Pseudomonas aeruginosa; cystic fibrosis; interspecific interactions: multispecies interactions; microbial communities; microbiome.

Figure 1.

Schematic representation of phenazine production by Pseudomonas aeruginosa growing in a biofilm in the cystic fibrosis lung. PA = P. aeruginosa, ECM = extracellular matrix, LE = lung epithelium.

Figure 2.

Summary of discussed interactions between Pseudomonas aeruginosa and other microbial inhabitants of the cystic fibrosis lung. Arrows depict the direction of the interaction. Note that we have omitted interactions driven by iron acquisition in this figure because the ability of siderophores to shape interactions is likely to be driven mainly by indirect effects of iron limitation.