Epidemiological and Genetic Overview of the Klebsiella pneumoniae Carbapenemases (KPCs) in K. pneumoniae Isolated from the Clinical Samples in Iran

Background: The prevalence of carbapenemresistant Enterobacteriaceae, especially Klebsiella pneumoniae carbapenemase (KPC), has been recently reported worldwide. Therefore, there is an indispensable need for precise and rapid detection of these carbapenemases. Objectives: This study aimed to propose an accurate and rapid method for detecting K. pneumoniae carbapenemase genes from clinical samples, using reverse transcriptionpolymerase chain reaction (RTPCR) and to evaluate the expression of these genes in the presence of βlactam antibiotic by realtime PCR assay.Methods: One hundred and eightyone K. pneumoniae strains were collected from patients presenting to Firoozgar Hospital of Tehran, Iran. The strains were tested using the disk diffusion method, the modified Hodge test (MHT), and Etest minimum inhibitory concentration (MIC). Next, reverse transcriptionPCR method was applied for the identification of bla OXA23 and bla OXA48 genes. Finally, expression of genes was measured by realtime PCR assay in the presence and absence of βlactam antibiotic.Results: Phenotypic testing also showed a high level of antibiotic resistance, while the genotypic methods indicated the presence and expression of carbapenemase genes.Conclusions: The findings suggest revisions in the current antibiotic therapy protocols, considering the high expression level of resistant carbapenemases to K. pneumoniae strains.