Antibiotic Resistance Profile of Klebsiella Isolates from Intensive Care Units: A Retrospective Evaluation

This study aimed to evaluate antibiotic resistance rates of Klebsiella isolates obtained from patients in the intensive care unit (ICU) of a tertiary hospital. Klebsiella isolates cultured from clinical specimens of adult ICU patients between June 2021 and December 2023 were analyzed retrospectively. Demographic data and microbiological results were obtained from the hospital information system. A total of 416 Klebsiella strains were isolated from 337 patients. The mean age was 71±14.9 years, with 52.2% male. The most common sample type was tracheal aspirate (44.0%), followed by urine (27.6%), blood (18.3%), and other specimens (9.1%). Extended-spectrum beta-lactamase (ESBL) production was detected in 326 isolates (78.4%). In this group, resistance to imipenem and meropenem was found to be 66.3% and 68.1%, respectively, while both rates were 1.1% among ESBL-negative isolates. Colistin resistance was observed in 17.8% of ESBL-positive strains, while only one (1.1%) ESBL-negative isolate was resistant. Overall resistance rates to carbapenems were 52.2% for imipenem and 53.6% for meropenem. The highest overall resistance rates were for ceftriaxone (78.4%), ceftazidime (77.2%), and ciprofloxacin (69.5%). The lowest resistance rates were observed for amikacin (31.0%) and colistin (14.2%). Annually, ESBL positivity rose from 73.7% in 2021 to 75.5% in 2022 and 83.1% in 2023. High rates of ESBL production and carbapenem resistance have been observed among Klebsiella isolates from ICUs, with carbapenem resistance exceeding 65% in ESBL-positive isolates, thereby limiting empirical treatment options. These findings underscore the urgent need to develop up-to-date antibiotic policies based on local resistance data and to strengthen effective antibiotic management programmes.