Microbial Colonization and Drug Resistance in Cystic Fibrosis

Cystic fibrosis (CF) is an autosomal recessive genetic disease. A mutation in the cystic fibrosis transmembrane conductance regulator (CFTR) gene caused impaired transport of chloride ions across the cell membrane. The most common microorganisms, identified in the cultures of respiratory secretions, are Staphylococcus aureus, Pseudomonas aeruginosa, and Burkholderia cepacia; recurrent infections by these microorganisms are associated with morbidity and mortality of CF patients. Severe inflammation of airways is the main cause of destruction and bronchiectasis, which may result in respiratory failure in these patients. The aim of this study was monitoring the clinical findings of laboratory tests, bacterial colonization, and antibiogram in CF patients at the Pediatric Pulmonary Department of Masih Daneshvari Hospital (Tehran, Iran) between 2006 and 2011. This cross-sectional study was on 23 children and young adults with CF, including 12 (52.2%) female and 11 (47.8%) male. The patients had a mean age of 14.5 ± 6.7 years. The sputum cultures of 10 patients (43.5%), including 5 female (41.7%) and 5 male (45.5%) were positive for P. aeruginosa. Also, in 2 cases (8.7%) it was positive for S. aureus, including 1 female (8.3%) and 1 male (9.1%). The sputum cultures of 2 other patients (8.7%) were positive for nontuberculous mycobacteria (NTM). The purified protein derivative (PPD) skin test were negative in 10 male (46%) and 12 female (55%). Based on the antibiograms obtained from sputum cultures, we found that P. aeruginosa had the highest susceptibility to ciprofloxacin (71.4%), followed by amikacin (50%), ceftazidime (30%), and ceftriaxone (18%). In this study, the prevalence of respiratory infections in patients who did not received prophylactic nebulized antibiotic was significantly higher than those patients who receive them (P