Molecular characterization of blaKPC, blaNDM1, and acrA Genes in Klebsiella Pneumoniae

Abstract

Klebsiella pneumonia (K. pneumonia) harboring blaKPC, blaNDM1, and acrA genes are highly resistant and inactivate all β-lactam antibiotics including carbapenems. This study aimed to molecularly characterization of these enzymes in K. pneumonia isolates. A total of sixty-seven clinical isolates of multiple drug-resistant (MDR) K. pneumonia were collected from different sites of infection, characterized and subjected to antimicrobial susceptibility testing, double-disc diffusion Synergy test (DDST) and Modified-Hodge test (MHT). blaKPC, acrA , blaNDM1 genes amplified by PCR. K. pneumonia isolates carrying these resistance genes were fully identified by 16S rRNA sequencing and the relatedness of isolates was analyzed through their phylogenetic tree. The most active antibiotics against K. pneumonia isolates were colistin (100%). Extended-spectrum β-lactamases (ESßLs) and Carbapenem- resistance were detected in 40% and 34.3% of tested isolates respectively. PCR amplifications revealed that 6 isolates harboured blaKPC and 2 isolates harboured blaNDM1 genes. The gene of acrA gene was detected in 4 isolates. The identification of K. pneumoniae isolates was confirmed by 16S rRNA sequencing. We conclude that, the early management of K. pneumonia infections needs efficient antibiotic therapy. Colistin is the drug of choice in treatment of these types of infection.