Escherichia coli harboring mcr-1 on a Novel Plasmid in a Mink

Abstract Background: Antimicrobial resistant Escherichia coli from mink can be transmitted to human through water environment. Therefore, it is necessary to routinely detect the presence of antimicrobial resistance genes of mink. Methods: In the current study, we described the characterization of an mcr-1-positive Escherichia coli isolate from a dead mink in Dongping Lake, China. The molecular characterization of plasmids was also investigated. Results: The strain was resistant to colistin, but it remained susceptible to several other agents, including amikacin, piperacillin-tazobactam and all carbapenems. Escherichia coli Mink_1 belonged to sequence type 140. Whole genome sequencing(WGS) showed that two plasmid, 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 Enterobacterale. Conclusion: Restrictive and rational use of antibiotics in animal husbandry should be taken to reduce the dissemination of mcr-1.