Pseudomonas aeruginosa: A persistent pathogen in cystic fibrosis and hospital-associated infections

Abstract

Over the past century, Pseudomonas aeruginosa has become an increasingly important pathogen, particularly in individuals with cystic fibrosis and in intensive care units worldwide. P. aeruginosa possesses a diverse array of virulence factors as well as high intrinsic resistance to many therapeutically-available antibiotics, lending to the characteristically high levels of lethality and persistence associated with P. aeruginosa infections. Furthermore, this bacterium has an unparalleled ability to adapt to the varying environments and stresses it encounters, as its large genome encodes numerous complex regulatory systems, and it readily acquires mobile genetic elements and plasmids. The finely tuned regulation of its virulence factors is best evidenced by the adaptations occurring during chronic cystic fibrosis infections, which contribute to the organism's ability to evade attack by host immune responses and also limits killing by all available antibiotics. Despite the major role this organism plays within the hospital, few effective antimicrobial agents with adequate anti-pseudomonal activity have been developed and resistance to all available agents has been reported.