Investigation of Carbapenem resistance mechanisms in Klebsiella pneumoniae by using phenotypic tests and a molecular assay

  • Esra Ciftci Public Health Laboratory, Antalya, Department of Medical Microbiology, Turkey
  • Emel Sesli Cetin Department of Medical Microbiology, Faculty of Medicine, Suleyman Demirel University, Isparta, Turkey
  • Ebru Us Department of Medical Microbiology, Faculty of Medicine, Ankara University, Ankara, Turkey
  • Hüseyin Haydar Kutlu Department of Medical Microbiology, Faculty of Medicine, Usak University, Usak, Turkey
  • Buket Cicioglu Arıdogan Department of Medical Microbiology, Faculty of Medicine, Suleyman Demirel University, Isparta, Turkey
Keywords: Carbapenemase, Klebsiella pneumoniae, KPC, NDM, OXA-48

Abstract

Introduction: The aim of this study was to investigate the presence of carbapenemase production and carbapenem resistance mechanisms in 47 carbapenem resistant Klebsiella pneumoniae isolates by phenotypic confirmatory tests and molecular assay.

Methodology: Carbapenem resistance genes KPC, OXA-48 and NDM were investigated with the BD MAX CRE assay kit in the BD MAX real time PCR instrument. Modified Hodge test, MBL gradient strip test, D70C Carbapenemase Detection Set, Temocillin gradient strip test methods were used as phenotypic confirmatory tests. Clonal relationship between study isolates was investigated with pulsed-field gel electrophoresis.

Results: Analysis with BD MAX CRE assay revealed OXA-48 positivity in 17 (36%) strains, NDM positivity in 6 (13%) strains and coexistence of OXA-48 + NDM positivity in 8 (17%) strains. In 16 (34%) strains, none of the KPC, OXA-48 and NDM genes were detected. While MHT was the most sensitive phenotypic confirmatory test, D70C disc set had not been considered as a useful tool to assist the search for carbapenemase production. Temocillin gradient test alone could not be considered as sufficient to detect the presence of OXA-48. PFGE analyses revealed that 23 of 31 carbapenemase producing strains were in three major PFGE genotypes (A, B and C).

Conclusions: This study revealed that carbapenem resistance observed in K. pneumoniae isolates was mainly due to OXA-48 and NDM genes and the increase of carbapenem resistance among K. pneumoniae strains in our hospital was due to the interhospital spread of especially 3 epidemic clones.

Published
2019-11-30
How to Cite
1.
Ciftci E, Sesli Cetin E, Us E, Haydar Kutlu H, Cicioglu Arıdogan B (2019) Investigation of Carbapenem resistance mechanisms in Klebsiella pneumoniae by using phenotypic tests and a molecular assay. J Infect Dev Ctries 13:992-1000. doi: 10.3855/jidc.10783
Section
Original Articles