Molecular characterization of carbapenemase producing Klebsiella pneumoniae strains by multiplex PCR and PFGE methods: The first K.pneumoniae isolates co-producing OXA-48/KPC and KPC/NDM in Turkey.

INTRODUCTION: Carbapenems are frequently used in the treatment of multidrug-resistant infections caused by Klebsiella pneumoniae. The aim of the study is to definition and incidence of transferable carbapenemase genes of carbapenem resistant K. pneumoniae (CRKP) and to determine clonal relatedness of these strains in tertiary care hospital in Turkey.

METHODS: Identification of all 100 K. pneumoniae isolates and low sensitivity to any of the carbapenem group antibiotics were determined by Vitek-2 (BioMérieux, France). The frequency of carbapenemase genes (blaOXA-48, blaNDM, blaKPC, blaVIM,blaIMP) and extended spectrum beta-lactamase (ESBL) genes (blaCTX-M, blaSHV, blaTEM) which frequently detected in Turkey, have been investigated by multiplex polymerase chain reaction (PCR). Clonal relatedness was determined using Pulsed-field gel electrophoresis(PFGE).

RESULTS: Ninety five isolates carried at least one of the carbapenemase genes (81.05% blaOXA-48, 38.9% blaNDM, 9.47% blaKPC,1.05% blaVIM). One isolate was carried the blaOXA-48+KPC and the two isolates were carried the blaKPC+NDM. PFGE demonstrated the presence of 24 pulse types and 63.09% of the isolates were in four main pulse types.

CONCLUSIONS: This study demonstrated the incidence of blaNDM is beginning to reach endemic levels, in addition to blaOXA-48 found endemic in Turkey. To our knowledge, this is the first report of the co-production of these two genes (blaKPC + NDM and blaOXA-48 + KPC) in CRKP isolates.