Pseudomonas aeruginosa Infection in Cystic Fibrosis: A Paradigm of Chronic Infection

Pseudomonas aeruginosa is a frequently encountered pathogen in multiple clinical settings. In acute infections, particularly in immunocompromised patients, the bacteria can increase expression of virulence factors such as type III secretion toxins with high mortality rates. In contrast, P. aeruginosa may cause chronic infections in patients with impaired local host defenses such as bronchiectasis. The best example of this is in patients with cystic fibrosis (CF) in which P. aeruginosa can reside for years to decades due to its ability to adapt in the CF lung. Changes by P. aeruginosa in patients with CF over time include the loss of virulence factors while also acquiring antibiotic resistance, making treatment difficult. This article reviews these adaptations in P. aeruginosa using the knowledge learned from study of patients with CF, which may also be applicable to other chronic lung diseases.