Bacterial Lung Infections in Cystic Fibrosis Patients

Abstract

Pa strains isolated in chronic infections usually show a biofilm mode of growth that reduces antimicrobial penetration and allows the bacteria to escape the host’s immune response. CF patients chronically infected by Pa show a steeper lung function decline (expressed as forced expired volume in 1 second decline over time), a higher number of pulmonary exacerbations, more hospital admissions and higher mortality than Pa-free patients. The effects of Pa are more severe if chronic infection develops early. Therefore, every episode of respiratory exacerbation should be treated with systemic antibiotic therapy. Long-term inhaled antibiotic therapy is now standard of care for chronic maintenance treatment in stable patients. 1,2 Effective antibiotic concentrations can be achieved in the airways by nebulization, avoiding side effects of intravenous antibiotics. Colistimethate sodium has been used by inhalation in Europe for many years. Tobramycin solution for inhalation was introduced in clinical practice after results of a rigorous clinical trial showed lung function improvement and reduction of pulmonary exacerbations. More recently, aztreonam lysine was found to be superior to tobramycin inhalation solution in a 6-month active comparator trial. 2