Escherichia coli Harboring Mcr-1 on a Novel Plasmid in a Mink in Eastern China

In the current study, we described the characterization of an mcr-1-positive E. coli isolate from a dead mink in Dongping Lake, China. The molecular characterization of plasmids was also investigated. The strain was resistant to colistin, but it remained susceptible to several other agents, including amikacin, piperacillin-tazobactam, all carbapenems, and ESBLs. E. coli Mink_1 belonged to sequence type 140. Whole Genome Sequencing (WGS) showed that two plasmids, pM1mcr and pM1ctx, coexisted in the same bacterial. Blast and phylogenetic tree imply that Epidemic plasmids are vehicles for the dissemination of colistin resistance genes among the Enterobacterales. Restrictive use of antibiotics in animal husbandry should be taken to reduce the dissemination of mcr-1.