Molecular detection of carbapenem-resistant genes in clinical isolates of Klebsiella pneumoniae.

INTRODUCTION

The emergence of carbapenem-resistant Klebsiella pneumoniae (CRKP) poses a considerable threat to public health worldwide. The aim of this study was to determine the prevalence of CRKP isolated from clinical specimens by phenotypic and genotypic methods.

METHODS

In total, 110 consecutive non-repetitive isolates of K. pneumoniae were analyzed. Minimal inhibitory concentrations (MICs) of imipenem were determined. The mechanism of resistance was evaluated by imipenem-EDTA combined disk test and modified Hodge test. PCR method was used for the detection of blaVIM, blaIMP, blaNDM-1, blaOXA-48 and KPC genes.

RESULTS

Totally, 8 (7.3 %) isolates were resistant to imipenem, showing MIC ≥4 µg/mL. Based on imipenem-EDTA combined disk test, all imipenem-resistant isolates were metallo-beta-lactamase (MBL) positive. PCR confirmed that 6 (75%) isolates were blaNDM-1 positive. Other resistance genes (blaVIM, blaIMP, blaOXA-48 and KPC) were not detected.

CONCLUSIONS

Based on this study, the prevalence of CRKP strains was not at a high level, however, continuous monitoring of antibiotic resistance should be performed to control dissemination of CRKP infections.