Changes in Antibiotic Resistance of Children with Cystic Fibrosis and Impact on Clinical Outcomes

Aim: Antibiotics have an important role in the treatment of cystic fibrosis (CF) lung disease. Antibiotic resistance, especially multidrug resistance (MDR), increases in CF. This study aimed to determine whether there is a change in antibiotic resistance of pathogens isolated from the respiratory tract specimens of CF patients and to evaluate the relationship between the antibiotic resistance and patients’ clinical status and pulmonary function. Material and Methods: Thirty-nine CF patients with identified microorganisms in respiratory tract specimens from August 2010 through December 2016 were included in the study. 333 respiratory cultures taken from 39 CF patients were analyzed retrospectively. Results: Methicillin-sensitive S. aureus (MSSA) was isolated from 122 (31.0%) cultures, P. aeruginosa from 97 (24.7%), and methicillin-resistant S. aureus (MRSA) from 22 (5.6%). The prevalence of MSSA (p=0.020) and MRSA (p=0.010) increased from 2010 to 2016, while the prevalence of P. aeruginosa and other microorganisms did not increase. MDR-S. aureus and MDR-P. aeruginosa prevalence did not change, but MRSA prevalence increased over the years (p=0.001). There was a significant relation between the antibiotic resistance and acute pulmonary exacerbations, pulmonary examination findings, loss in weight and height percentile. As the antibiotic resistance increased, FEV1, FVC, FEV1/FVC, PEF, and FEF25-75 were significantly decreased. The use of long-term azithromycin or inhaled antibiotics was not associated with antibiotic resistance. Conclusion: In CF patients, resistance to antibiotics increased over the years. It is important to obtain respiratory tract cultures regularly and initiate rational antibiotic treatment based on culture results.