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

The prevalence of carbapenem-resistant 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. This study aimed to propose an accurate and rapid method for detecting K. pneumoniae carbapenemase genes from clinical samples, using reverse transcription-polymerase chain reaction (RT-PCR) and to evaluate the expression of these genes in the presence of β-lactam antibiotic by real-time PCR assay. One hundred and eighty-one 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 E-test minimum inhibitory concentration (MIC). Next, reverse transcription-PCR method was applied for the identification of bla OXA-23 and bla OXA-48 genes. Finally, expression of genes was measured by real-time PCR assay in the presence and absence of β-lactam antibiotic. Phenotypic testing also showed a high level of antibiotic resistance, while the genotypic methods indicated the presence and expression of carbapenemase genes. The findings suggest revisions in the current antibiotic therapy protocols, considering the high expression level of resistant carbapenemases to K. pneumoniae strains.