Investigation of Antibiotic Susceptibilities in Carbapenem-Resistant Klebsiella pneumoniae and Escherichia coli Strains Isolated from Clinical Samples: A Four-Year Analysis in a Comprehensive Healthcare Facility

INTRODUCTION: The profile of carbapenem-resistant Enterobacterales (CRE), antibiotic susceptibilities were analyzed in our hospital providing a wide range of healthcare services in Southeastern Anatolia. METHODS: This retrospective study included carbapenem-resistant Klebsiella pneumoniae (CRKP, 1022 isolates) and carbapenem-resistant E. coli (CREC, 700 isolates) isolated from patients admitted to xxxxxx Hospital between 2019 and 2022. Isolate typing and antibiotic susceptibility profiles were determined using the BD Phoenix automated system (Becton Dickinson, USA), and the Diagnostics MIC-COL test kit (Diagnostics, Slovakia) was used to determine colistin susceptibility. RESULTS: Out of the total 1022 CRKP isolates, 663 (64.9%) were obtained from intensive care units, 207 (20.2%) from inpatient clinics, and 152 (14.9%) from outpatient clinics. The most sensitive antibiotics for CRKP isolates were found to be ceftazidime-avibactam (CZA) (57%), gentamicin (51%), and amikacin (40%), respectively. Statistically significant changes in susceptibilities to CZA, colistin, trimethoprim-sulfamethoxazole (SXT), tobramycin, meropenem, imipenem, and levofloxacin were observed over the years (p<0.05). Among the total 700 CREC isolates, 258 (36.9%) were obtained from inpatient clinics, 229 (32.7%) from intensive care units, and 213 (30.4%) from outpatient clinics. Statistically significant changes in susceptibilities to imipenem, tobramycin, SXT, levofloxacin, cefepime, ampicillin-sulbactam (AMP-SM), and cefuroxime were observed over the years (p<0.05). Over 80% of the isolates were susceptible to amikacin, and over 60% were susceptible to gentamicin, imipenem, colistin, and CZA. DISCUSSION AND CONCLUSION: Presentation of regional data on carbapenem resistance in health centers and understanding of antibiotic resistance/susceptibility specific to CSI are vital to guide empirical treatment decisions as well as provide important regional epidemiological data.