The airway metagenome of monozygous cystic fibrosis twins

Chronic microbial airway infections are the major morbidity that determines quality of life and prognosis in most people with cystic fibrosis (CF). CF airways are colonized with poly-microbial communities, but a few pathogens are the drivers of a vicious cycle of infection, inflammation and remodeling, namely Staphylococcus aureus, Pseudomonas aeruginosa, Burkholderia spp., and emerging pathogens such as nontuberculous mycobacteria (NTM) and multidrug-resistant proteobacteria such as Achromobacter spp. The predisposition to colonization with opportunistic pathogens in CF should be governed by the CFTR genotype and the severity of the basic defect, genetic factors other than CFTR, the general condition and a variety of environmental factors that shape the exposure to the microbial world such as geographic origin, climate and living conditions. However, stochastic factors may also influence the composition of the microbiome in CF lungs. To estimate the relative importance of accidental and non-random genetic and environmental factors we investigated the airway microbiota in monozygous CF twin pairs of variable CFTR residual activity.