Dissemination of NDM-1 and OXA-48 Co-producing Carbapenem-resistant Enterobacterales at Two Tertiary Hospitals in Egypt

Background. The global incidence of carbapenem-resistant Enterobacterales (CRE) is increasing, posing a major treatment challenge and serious infection control concern. Objective. We aimed to characterize carbapenemases both genotypically and phenotypically among CRE isolated from two tertiary hospitals in Egypt, and to detect the genetic relatedness among studied isolates. Methodology. A total of 107 non-duplicate CRE strains isolated from different clinical specimens of hospitalized patients were assessed for presence of carbapenemases genes using multiplex PCR. One-hundred isolates were also assessed for the presence of carbapenemases using MASTDISCS Combi Carba Plus kit. Molecular typing of the isolates was done by Enterobacterial Repetitive Intergenic Consensus region PCR (ERIC-PCR). Results. Klebsiella pneumoniae (K. pneumoniae) represented most of the studied isolates (n=85; 79.4%). The most prevalent carbapenemase gene among our isolates was blaNDM-1 (n=103; 96.2%) followed by blaOXA-48 (n=68; 63.5%). Among them, 64 isolates (59.8%) carried more than one gene as blaNDM-1 and blaOXA-48 genes. blaKPC, blaVIM and blaIMP were not detected in the isolates. The sensitivity of the Carba Plus kit for the detection of MBL was much better than OXA-48 (82.29% and 9.52%, respectively), however, the negative predictive value was poor for the detection of both (19.05% and 39.36%, respectively). The constructed dendrogram for each genus from each hospital revealed significant genetic diversity among the investigated isolates. Conclusions. The study highlights the wide dissemination of diverse clones of CRE isolates that co-harbor blaOXA-48 and blaNDM-1 genes among our hospitals as well as low accuracy of detection using phenotypic techniques like Carba plus kit.