Prevalence, Clinical Characteristics, and Antibiotic Resistance of Carbapenem-Resistant Klebsiella pneumoniae in a Tertiary Hospital in Türkiye (2023–2025)

Background: Carbapenem-resistant Klebsiella pneumoniae (CRKP) represents a growing public health threat due to limited treatment options, high morbidity and mortality rates. This study aimed to investigate the prevalence, clinical characteristics, and antibiotic resistance profiles of CRKP isolates identified in a tertiary hospital in Türkiye between 2023 and 2025. Methods: A retrospective observational study was conducted using microbiological and clinical data collected from patients diagnosed with CRKP infections between January 2023 and April 2025. A total of 1588 CRKP isolates were retrospectively analyzed and compared with patient clinical data. Bacterial identification and antimicrobial susceptibility testing were performed using the BD Phoenix 100 M50 automated system (Becton Dickinson Company, USA), and results were interpreted in accordance with the European Committee on Antimicrobial Susceptibility Testing (EUCAST) guidelines. Results: Among 2376 K. pneumoniae isolates, the overall CRKP prevalence was 66.8%. The annual carbapenem resistance rates were 64.9% in 2023, 69.4% in 2024, and 61.0% in 2025, respectively. Resistance rates among CRKP isolates were as follows: tigecycline 14.7%, colistin 23.0%, fosfomycin 47.6%, ceftazidime-avibactam 50.9%, and amikacin 66.8%. The prevalence of CRKP was significantly higher among inpatients (83.8%) compared to outpatients (26.8%). Of the CRKP-positive samples, 62.5% were collected from patients in intensive care units (ICUs), 12.2% from hematology, and 5.1% from oncology departments. Tracheal aspirates accounted for 43.5% of isolates, followed by urine samples at 25.8%. Conclusions: The study revealed a notably high prevalence of CRKP with substantial resistance to most commonly used antibiotics. Among the tested antibiotics, tigecycline showed the lowest resistance rate, consistent with its limited usage profile. CRKP infections predominantly affected elderly male patients and were most frequently associated with lower respiratory tract infections. These findings underscore the urgent need for strengthened infection control measures and may guide more effective empirical treatment strategies for CRKP infections in the region.