Microbial Colonization and Drug Resistance in Patients with Cystic Fibrosis

Abstract

Background: Cystic fibrosis (CF) is a genetic disease with an autosomal recessive pattern of inheritance. CF caused by a mutation in the cystic fibrosis transmembrane conductance regulator (CFTR) gene and characterized by impaired transport of chloride ions across the cell membrane. Staphylococcus aureus, Pseudomonas aeruginosa, and Burkholderia cepacia have been identified in the cultures of respiratory secretions of CF patients, and infections of these microorganisms are associated with high rates of morbidity and mortality. In patients with CF, severe inflammation of the airway can cause advanced bronchiectasis, which may result in respiratory failure and death. Objectives: This study aimed at evaluating the clinical findings of laboratory tests, bacterial colonization, and drug resistance in children and young adults with CF who hospitalized at the Pediatric Pulmonary Department of Masih Daneshvari Hospital, Tehran, Iran. Patients and Methods: This cross-sectional study was conducted on 22 children and young adults with CF who were hospitalized at the Pediatric Department of Masih Daneshvari Hospital between 2006 and 2011, with convenient sampling. All analysis performed with SPSS V 11.5 and P values less than 0.05 considered as statistically significant. Results: A total number of 23 patients evaluated, including 12 (52.2%) girls and 11 (47.8%)boys. Patients had a mean age of 14.5 ± 6.7 years. The sputum cultures of 10 (43.5%) (95%CI, 23.2-63.7%) patients [5 female (41.7%) and 5 male (45.5%)] were positive for P. aeruginosaand those of 2 (8.7%) (95% CI, 0-20.2%) were positive for S. aureus [1 female (8.3%) and 1 male (9.1%)]. The sputum cultures of 2 (8.7%) (95% CI, 0-20.2%) other patients were positive for nontuberculous mycobacteria (NTM). The purified protein derivative (PPD) skin test yielded negative results 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 annual prevalence of respiratory infections in patients who given nebulized antibiotic prophylaxis was significantly lower than that in patients who did not receive this treatment (P < 0.05). Conclusions: Our study results (43.5% cultures positive for P. aeruginosa and high resistance to antipseudomonal drugs) suggest that the use of inhaled medications for prophylaxis in CF patients could result in a decreased rate of hospitalization and reduction in CF-related complications.