Bacterial host interactions in cystic fibrosis

Chronic infection is a hallmark of cystic fibrosis (CF) and the main contributor to morbidity. Microbial infection in CF is complex, due to the number of different species that colonise the CF lung. Their colonisation is facilitated by a host response that is impaired or compromised by highly viscous mucous, zones of hypoxia and the lack of the cystic fibrosis transmembrane regulator (CFTR). Successful dominant CF pathogens combine an effective arsenal to establish infection and counter-attack the host response, together with an ability to adapt readily to an unfavourable environment. Hypermutability is common among CF pathogens facilitating adaptation and as the host response persists, progressive destruction of the normal architecture of lung tissue ensues with catastrophic consequences for the host.

► CF microbiology is complex, a range of opportunistic pathogens have been isolated.
► Host immune response is impaired and dysregulated by chronic infection.
► CF pathogens adapt very efficiently to the CF lung, facilitating chronic infection.
► Adaptations include host response evasion, iron acquisition, antibiotic resistance.
► More studies are needed on minority pathogens within the polymicrobial community.