Multidrug-resistant bacteria in hospitalized patients with cystic fibrosis: a retrospective cross-sectional study

Aims: The emergence of multidrug-resistant (MDR) bacterial pathogens has become a critical clinical challenge in cystic fibrosis (CF) patients. This study aimed to characterize MDR bacterial isolates in hospitalized CF patients experiencing pulmonary exacerbations. Methods: We defined MDR as resistance to three or more antimicrobial classes. The study included 45 acute exacerbation episodes with confirmed MDR bacterial growth among 32 CF pediatric patients hospitalized at Marmara University Pendik Training and Research Hospital. Results: Among 32 CF patients (mean age: 114.7±62.1 months; 68.8% female), we analyzed 45 exacerbation episodes. The most common clinical manifestations were increased sputum production (73.3%), cough (60%), and fever (31%). Pseudomonas aeruginosa colonization was previously documented in 55.6% of cases. Respiratory cultures revealed MDR bacteria in all patients, with P. aeruginosa (53.4%), Staphylococcus aureus (17.8%), and Acinetobacter baumannii (4.4%) being the predominant isolates. Combination antibiotic therapy was required in 82% of cases (37/45), while only 18% (8/45) received monotherapy. The mean hospitalization duration was 17.3±8.4 days, with an overall mortality rate of 6.2% (n=2). Conclusion: MDR infections in CF patients demand a multifaceted approach. Rotating antibiotic regimens and avoiding carbapenem overuse may reduce resistance. Tailored antibiotic regimens and antimicrobial stewardship programme, robust infection controls such as enhanced screening for MDR colonization and isolation protocols are needed to curb transmission, and sustained research into emerging pathogens. Our data reinforce the urgent need for CF-specific antimicrobial protocols in Turkiye and similar countries.