NDM-1 carbapenemase resistance gene vehicles emergent on distinct plasmid backbones from the IncL/M family.

The use of sequencing helped inform: (i) a wide geographical distribution of isolates encoding NDM-1 on emergent IncM2 plasmids; (ii) variant plasmids have acquired NDM-1 separately; and (iii) dynamic arrangements and evolution of the resistance elements in this plasmid group. The geographical and temporal distribution of IncM2 plasmids that encode NDM-1 highlights them as a public health threat that requires ongoing monitoring.