Identification of a Novel NDM Variant, NDM-13, from a Multidrug-Resistant Escherichia coli Clinical Isolate in Nepal

A novel New Delhi metallo-beta-lactamase, NDM-13, was identified in a carbapenem-resistant Escherichia coli clinical isolate obtained from the urine of a patient in Nepal. The enzymatic activity of NDM-13 against beta-lactams was similar to that of NDM-1. However, NDM-13 displayed significantly higher kcat/Km ratios for cefotaxime. The genetic environment of blaNDM-13 was determined to be tnpA-IS30-blaNDM-13-bleMBL-trpF-dsbC-cutA-groES-groL, with blaNDM-13 located within the chromosome.