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

ABSTRACT

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 (n16) sequence type by MLST. ST 101 (n7), ST14 (n6), ST 147 and ST 15 (n4), ST391 (n3), ST 377 and ST16 (n2), ST22, ST 307, ST 985, ST 336, ST 345, and ST 3681 (n1) were classified in other isolates. In Istanbul and Ankara ST2096 was common. Among Turkey isolates, the most common clonal complexes (CC) were CC14 (n26) 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.