Pseudomonas aeruginosa is a common respiratory
pathogen in patients with cystic fibrosis, but details about P aeruginosa acquisition, progression, and clinical effects are lacking. Li and colleagues conducted a prospective investigation of the epidemiology
of P aeruginosa and related pulmonary morbidity in 56 children with cystic fibrosis. They found the median
age of infection with nonmucoid P aeruginosa was
1 year. After a median of 10.9 years, colonization with a mutant mucoid phenotype
of P aeruginosa was documented. Clinical deterioration
was seen with nonmucoid P aeruginosa infection, but
deterioration was greater with transition to the mucoid strain.