Emergence of NDM-5- and MCR-1-producing Escherichia coli clones ST648 and ST156 from a single Muscovy duck (Cairina moschata)

Abstract

Two Escherichia coli clones (sequence type 648 [ST648] and ST156) that coproduce NDM-5 and MCR-1 were detected from a single fowl in China. The blaNDM-5 gene was found on the two indistinguishable IncX3 plasmids from the two different E. coli isolates, whereas the mcr-1 gene was located on IncHI2 and IncI2 plasmids, respectively, suggesting that blaNDM-5 and mcr-1 have spread in avian intestinal flora. Also, the two strains harbor blaTEM-1, blaCTX-M-55, fosA3, and aac(6′)-Ib. The multiresistant E. coli strains (especially the epidemic clone ST648) might raise a potential threat to human health via food chain transmission.