Diversified <i>mcr-1</i> -Harbouring Plasmid Reservoirs Confer Resistance to Colistin in Human Gut Microbiota

Abstract

The plasmid-mediated mobile colistin resistance gene (mcr-1) challenged greatly the conventional idea mentioned above that colistin is an ultimate line of refuge against lethal infections by multidrug-resistant Gram-negative pathogens. It is a possibility that diversified dissemination of themcr-1gene might be greatly underestimated. We report three cases of plasmid-carried MCR-1 colistin resistance in isolates from gut microbiota of diarrhea patients and functionally define the colistin resistance conferred purely by the singlemcr-1gene. Genetic and sequence mapping revealed unexpected diversity among themcr-1-harbouring plasmid reservoirs of human gut microbiota.