Carbapenem and Colistin Resistance, Integrons and Plasmid Replicon Types in Multi-Drug Resistant Klebsiella Strains Isolated in Turkey

Multidrug-resistant (MDR) Klebsiella is a globally important nosocomial pathogen. In the present study, 101 multidrug-resistant Klebsiella strains isolated from various clinical specimens obtained from two different Medical Faculties' hospitals were involved. We aimed to find out the prevalence of carbapenemase, mobile colistin resistance genes, and integrons in MDR Klebsiella strains.The antibiotic susceptibilities of strains were determined by Kirby Bauer disc-diffusion method and resistance to colistin was confirmed by detection of minimum inhibitory concentrations. The prevalence of carba-penemase genes (blaOXA-48, blaNDM, blaIMP, blaVIM, blaKPC), mobile colistin-resistance genes (mcr-1 and mcr-2), and integrons (class I, II and III) were examined in Klebsiella strains by polymerase chain reaction.All strains were resistant to β-lactam antibiotics, carbapenems, and quinolones. On the other hand, only nine (8.9%) strains were resistant to colistin. The most common carbapenemase genes were blaNDM (64.3%) and blaOXA-48 (53.5%). Besides, 28 (27.7%) strains were found to harbor both blaNDM and blaOXA-48. These 28 strains be-longed to the IncA/C (18.7%), IncL/M (7.7%), and IncFIIs (1.1%) plasmid replicon types. No strain was positive for blaIMP, mcr-1, and mcr-2. Class I and Class II integrons were shown to be harbored in 83.2% and 63.3% of strains, respectively. In total, 63 (63.6%) of strains harbored both classes I and II integrons. Class III integron was not detected. There was a statistically significant relationship between the presence of integrons and antibiotic resistance for cefotaxime (p = 0.024), ciprofloxacin (p < 0.001) trimethoprim/sulfamethoxazole (p < 0.001) and levofloxacin (p = 0.002). To our knowledge, this study represents the first report of a human isolate for the co-presence of blaNDM, blaOXA-48 and both Class I and Class II integrons, from Turkey.Our findings also highlight the dissemination of integrons and carbapenemases and the importance of surveillance on emerging antibiotic resistance.