Multidrug-resistant Pseudomonas aeruginosa is Predisposed to lasR Mutation through Up-regulated Activity of Efflux Pumps in Non-cystic Fibrosis Bronchiectasis Patients

Multidrug-resistant (MDR) Pseudomonas aeruginosa is a frequent opportunistic pathogen that causes significant mortality in patients with non-cystic fibrosis bronchiectasis (NCFB). Although quorum sensing (QS) system is a potential target for treatment, lasR mutants that present with QS-deficient phenotype have been frequently reported among clinical P. aeruginosa isolates, and their association with antibiotic resistance has been poorly understood. We aimed to investigate whether the antibiotic resistance would select for lasR mutants during chronic P. aeruginosa lung infection, and determine the mechanism underlying the phenomenon