Diverse flanking sequence types ofbla_NDMin IncX3 and IncB/O/K/Z plasmids inEscherichia coliisolated from poultry

Abstract

We identified 33 bla NDM -harboring Escherichia coli in 470 poultry samples from 9 Shandong and Guangdong provinces during 2016 to 2017 and included the subtypes bla NDM-1 , 10 bla NDM-5 and bla NDM-9. The bla NDM gene possessed by all strains was plasmid-borne and ranged in 11 size from 46 to 265 kb. The plasmids included the replicon types IncX3, IncY, IncB/O/K/Z and 12 IncHI2 and most were transferable and stable in recipient host bacteria. Sequences flanking 13 bla NDM in IncX3 and IncB/O/K/Z plasmids were diverse and the mobile element IS26 played an 14 important role in the evolution of the IncB/O/K/Z bla NDM plasmids. 15