Emergence of NDM-5- and MCR-1-Producing Escherichia coli Clones ST648 and ST156 from a Single Muscovy Duck (Cairina moschata)

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 bla NDM-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 bla NDM-5 and mcr-1 have spread in avian intestinal flora. Also, the two strains harbor bla TEM-1 , bla CTX-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.