New Delhi metallo-β-lactamase (NDM) compromises the efficacy of almost all β-lactam antibiotics, including carbapenems. This study aimed to screen for the blaNDM-1-type gene and NDM-1-type carbapenemase production among Gram-negative bacteria in Cairo University Pediatric Hospital (Cairo, Egypt). Among 382 Gram-negative clinical isolates collected over the period October 2013 to May 2014, 100 clinical isolates showing reduced carbapenem (imipenem and meropenem) susceptibility were included in this study. Initial phenotypic screening for NDM enzyme production was performed by Etest for metallo-β-lactamases (EMBL). Genotypic detection of the blaNDM-1-type gene was done by TaqMan real-time PCR. Metallo-β-lactamase production was detected in 23% of the isolates by EMBL, whereas 24% of the isolates were found to be positive for the blaNDM-1-type gene by real-time PCR. The EMBL sensitivity was 79.2%, specificity was 94.7%, positive predictive value was 82.6%, negative predictive value was 93.5% and overall accuracy was 91.0%. Seventeen (70.8%) of blaNDM-1-type-positive cases were hospital-acquired in origin, whilst 7 cases (29.2%) were community-acquired. Eleven isolates (45.8%) harbouring blaNDM-1-type were found in critical care units. In conclusion, the high prevalence of blaNDM-1-type carbapenemase gene among Gram-negative bacteria, with its great potential for spread in intensive care units, warrants the attention of a nationwide surveillance programme to contain its spread.
Keywords: Carbapenemase; Etest; Imipenem; MBL; MIC; NDM-1-type.
Copyright © 2016 International Society for Chemotherapy of Infection and Cancer. Published by Elsevier Ltd. All rights reserved.