Dynamics of adaptive microevolution of hypermutable Pseudomonas aeruginosa during chronic pulmonary infection in patients with cystic fibrosis.

Background: In patients with cystic fibrosis (CF), the emergence of hypermutable Pseudomonas aeruginosa drives the selection of P. aeruginosa variants that are efficiently adapted to the inflamed lungs of these patients.

Objective: To provide a detailed survey of adaptive changes in the physiology of P.

Stage-specific adaptation of hypermutable Pseudomonas aeruginosa isolates during chronic pulmonary infection in patients with cystic fibrosis.

Background: Pseudomonas aeruginosa (PA) strains with defective DNA mismatch repair genes generate numerous bacterial variants because of high mutation rates. In cystic fibrosis (CF), such mutator strains may lead to the rapid selection of survivors that are specifically adapted to the hostile environment of the inflamed CF lung.

Methods: Genotypes and phenotypes of 111 PA variants descending from 3 distinct mutator strains obtained from 3 patients with CF were systematically characterized.