Molecular epidemiological investigation of carbapenem resistant Klebsiella pneumoniae isolated from intensive care unit patients of six geographical regions of Turkey

Introduction: Klebsiella pneumonia causes serious infections in hospitalized patients. In recent years, carbapenem-resistant infections increased in the world. The molecular epidemiological investigation of carbapenem-resistant K. pneumoniae isolates was aimed in this study.Methodology: Fifty carbapenem-resistant K. pneumoniae isolates from six geographical regions of Turkey between September 2019-2020 were included in the study. The disk diffusion method was used for the antibiotic susceptibility testing. The microdilution confirmed colistin susceptibility. Genetic diversity was investigated by MLST (Multi-Locus Sequence Typing).Results: The resistance rates were as follows: 49 (98%) for meropenem, 47 (94%) imipenem, 50 (100%) ertapenem, 30 (60%) colistin and amoxicillin-clavulanate, 49 (98%) ceftriaxone, 48 (96%) cefepime, 50 (100%) piperacillin-tazobactam, 47 (94%) ciprofloxacin, 40 (80%) amikacin, 37 (74%) gentamicin. An isolate resistant to colistin by disk diffusion was found as susceptible to microdilution. ST 2096 was the most common (n:16) sequence type by MLST. ST 101 (n:7), ST14 (n:6), ST 147 and ST 15 (n:4), ST391 (n:3), ST 377 and ST16 (n:2), ST22, ST 307, ST 985, ST 336, ST 345, and ST 3681 (n:1) were classified in other isolates. In Istanbul and Ankara ST2096 was common. Among Turkey isolates, the most common clonal complexes (CC) were CC14 (n:26) and CC11 (n = 7).Conclusions: In Turkey, a polyclonal population of CC14 throughout the country and inter-hospital spread were indicated. The use of molecular typing tools will highlight understanding the transmission dynamics.