Pseudomonas colonization in cystic fibrosis. A study of 160 patients.

We investigated the role of Pseudomonas aeruginosa colonization in the respiratory tracts of cystic fibrosis (CF) patients to relate the effect of this colonization to progression of bronchial airway pathologic conditions and to the patients' clinical progress, and to identify predisposing factors to persistence of P aeruginosa colonization and bronchial tree damage. Half of 160 CF patients studied had persistent P aeruginosa respiratory tract colonization; the other half had none. Pseudomonas aeruginosa seems to have an exclusive propensity for the respiratory tract and may appear at any age. Treatment with antibiotics, including aminoglycosides, failed to eradicate P aeruginosa. The continuous use of antibiotics seemed to contribute to the persistence of P aeruginosa and the appearance of mucoid strains of P aeruginosa.