Molecular characterization of Carbapenem-resistant Klebsiella pneumoniae isolated from wound infections

Carbapenem-resistant Klebsiella pneumoniae

Abstract

Carbapenem-resistant Klebsiella pneumoniae (CRKP) isolates can increase the mortality among hospitalized patients as a result of serious infections. Molecular studies provide valuable information about the mechanisms of resistance among the resistant isolates. The aim of this study was to investigate the phenotypic and molecular characteristics of the carbapenem-resistance K. pneumoniae isolates and detect the Metallo-Beta-Lactamases  (MBLs) encoding genes in these isolates which obtained from patients with wound infections hospitalized in two hospitals in Baghdad, Iraq. In this study, 55 K. pneumoniae isolates were collected from wound swabs of patients, who referred to Al-Kindy and Al-Yarmook hospitals in Baghdad during January to October 2018. Resistance to carbapenems was investigated by disc-diffusion and E-test methods. Ethylenediaminetetraacetic acid (EDTA)-combine disc (ECD) methods were performed to determine carbapenemases. Carbapenemase-encoding genes including blaNDM-1, blaOXA-48, and blaKPC were investigated by polymerase chain reaction (PCR). Among the 55 K. pneumoniae isolates, 18 (32.7%) were resistant to Imipenem, whereas 11 (20%) were resistant to Meropenem. All carbapenems-resistant K. pneumoniae isolates (n=18) were positive with MBL production. Also, the resistances to third and fourth generation cephalosporins were taken into consideration. The blaOXA-48, blaNDM-1 and blaKPC were found in 83.3% (n = 15), 55.5% (n = 10) and 16.6% (n = 3), of the resistant isolates, respectively. Phylogenetic analysis showed very less variation in blaNDM-1 gene with respect to blaNDM-1 possessing K. pneumoniae isolates from other parts of Iraq and abroad. In conclusion, the present study revealed a high frequency of MBL production and the presence of blaOXA-48 among local K. pneumoniae strains, this study indicated that resistance to carbapenems and isolation of bacteria producing blaOXA-48 and blaNDM-1 is increasing.