Epidemiology, biology, and impact of clonal pseudomonas aeruginosa infections in cystic fibrosis

Abstract

Chronic lower airway infection with Pseudomonas aeruginosa is a major contributor to morbidity and mortality in individuals suffering from the genetic disease cystic fibrosis (CF). Whereas it was long presumed that each patient indepen-dently acquired unique strains of P. aeruginosa present in their living environment, multiple studies have since demonstrated that shared strains of P. aeruginosa exist among individuals with CF. Many of these shared strains, often referred to as clonal or epidemic strains, can be transmitted from one CF individual to another, poten-tially reaching epidemic status. Numerous epidemic P. aeruginosa strains have been described from different parts of the world and are often associated with an antibiotic-resistant phenotype. Importantly, infection with these strains often por-tends a worse prognosis than for infection with nonclonal strains, including an increased pulmonary exacerbation rate, exaggerated lung function decline, and pro-gression to end-stage lung disease. This review describes the global epidemiology of clonal P. aeruginosa strains in CF and summarizes the current literature regarding the underlying biology and clinical impact of globally important CF clones. Mechanisms associated with patient-to-patient transmission are discussed, and best-evidence practices to prevent infections are highlighted. Preventing new infections with epidemic P. aeruginosa strains is of paramount importance in mitigating CF disease progression.