Abstract

Carbapenem-resistant Klebsiella pneumoniae carrying blaKPC-2, blaOxa48, and other metallo--lactamases (MBLs) are difficult to treat. This study was conducted to study the phenotypic and genotypic features of carbapenem resistance in isolates of K. pneumoniae isolated from a tertiary care hospital in the European region of Turkey. Isolates of K. pneumonia (n=100) resistant to at least one carbapenem (imipenem, meropenem, or ertapenem) were collected from 60 patients for 14 months. Carbapenem resistance was determined via the VITEK-2 system and the E-test confirmed this. The Modified Hodge Test (MHT) and Double Disc Synergy Test (DDST) were performed. Genes were analyzed by Sybr-Green real-time, multiplex and convensional polymerase chain reaction (PCR). Phylogenetic relatedness was analyzed by ERIC-PCR. The rate of resistance by E-test against ertapenem, imipenem, and meropenem were 98, 94, and 72%, respectively; 21% of isolates were somewhat susceptible to tygecycline. The MHT positivity was 98% and DDST was negative in all cases. There were 19 and 24% of isolates positive for blaKPC-2 and blaOxa-48, respectively. ERIC-PCR showed that all blaKPC-2-positive isolates were branched into two main clusters with 80.5% similarity. The results indicate that blaKPC-2 mediated carbapenem-resistant Klebsiella pneumoniae (CRKP) infection is spreading in Turkey and blaOXA-48 endemicity continues to be a serious problem. The molecular determination of carbapenemases will be useful for patients with concurrent carbapenem-resistant Enterobacteria¬ceae (CRE) infections. This could prevented outbreaks and complications.

Key words: Klebsiella pneumoniae, carbapenem resistance, blaKPC-2, blaOxa-48.