Extensive diversification is a common feature of Pseudomonas aeruginosa populations during respiratory infections in cystic fibrosis

BackgroundPopulations of the Liverpool Epidemic Strain (LES) of Pseudomonas aeruginosa undergo extensive diversification in the cystic fibrosis (CF) lung during long-term chronic infections.MethodsWe analyzed sets of 40 isolates from the sputa of five CF patients, each chronically infected with a different non-LES strain of P. aeruginosa. For each sample (two per patient), diversity was assessed by characterizing nine phenotypic traits.ResultsAll P. aeruginosa populations were highly diverse, with the majority of phenotypic variation being due to within-sample diversity.ConclusionsMaintenance of diverse populations in the CF lung is a common feature of P. aeruginosa infections.