Identification of a novel plasmid-mediated colistin resistant gene mcr-2 in E. coli. Identification of a novel plasmid-mediated colistin resistant gene mcr-2 in E. coli

We identified a novel plasmid-mediated colistin resistance gene in porcine and bovine colistin-resistant E. coli that did not show presence of mcr-1. This gene, which we termed as mcr-2, is a 1617 bp phosphoethanolamine transferase, 9 bp shorter than mcr-1, and shows 76.7 % and 80.78% identity to mcr-1 at nucleotide and protein levels, respectively. The mcr-2 -harbouring plasmid is 35,104 bp, it harbours 56 protein encoding genes and belongs to IncX4 incompatibility type.