A Novel Variant, NDM-5, of the New Delhi Metallo-β-Lactamase in a Multidrug-Resistant Escherichia coli ST648 Isolate Recovered from a Patient in the United Kingdom

A new variant of the New Delhi metallo-enzyme (NDM) carbapenemase was identified in a multidrug-resistant Escherichia coli ST648 isolate recovered from the perineum and throat of a patient in the United Kingdom with a recent history of hospitalization in India. NDM-5 differed from existing enzymes due to substitutions at positions 88 (Val -> Leu) and 154 (Met -> Leu) and reduced the susceptibility of E. coli TOP10 transformants to expanded-spectrum cephalosporins and carbapenems when expressed under its native promoter.