Evaluation of carbapenem resistance using phenotypic and genotypic techniques in Enterobacteriaceae isolates

Background: Bacterial resistance to antibiotics is increasing worldwide. Antibiotic-resistant strains can lead to seri-ous problems regarding treatment of infection. Carbapenem antibiotics are the final treatment option for infections caused by serious and life-threatening multidrug-resistant gram-negative bacteria. Therefore, an understanding of carbapenem resistance is important for infection control. In the study described herein, the phenotypic and geno-typic features of carbapenem-resistant Enterobacteriaceae strains isolated in our hospital were evaluated. Methods: In total, 43 carbapenem-resistant strains were included in this study. Sensitivity to antibiotics was deter-mined using the VITEK®2 system. The modified Hodge test (MHT) and metallo-β-lactamase (MBL) antimicrobial gradient test were performed for phenotypic identification. Resistance genes IMP, VIM, KPC, NDM-1, and OXA-48 were amplified by multiplex PCR. Results: The OXA-48 gene was detected in seven strains, and the NDM-1 gene in one strain. No resistance genes were detected in the remainder of strains. A significant correlation was observed between the MHT test and OXA-48 positivity, and between the MBL antimicrobial gradient test and positivity for resistance genes (p < 0.05). Conclusion: The finding of one NDM-1-positive isolate in this study indicates that carbapenem resistance is spread-ing in Turkey. Carbapenem resistance spreads rapidly and causes challenges in treatment, and results in high mortal-ity/morbidity rates. Therefore, is necessary to determine carbapenem resistance in Enterobacteriaceae isolates and to take essential infection control precautions to avoid spread of this resistance