Plasmid-mediated colistin resistance in animals: current status and future directions

Abstract

AbstractColistin, a peptide antibiotic belonging to the polymyxin family, is one of the last effective drugs for the treatment of multidrug resistant Gram-negative infections. Recent discovery of a novel mobile colistin resistance gene,mcr-1, from people and food animals has caused a significant public health concern and drawn worldwide attention. Extensive usage of colistin in food animals has been proposed as a major driving force for the emergence and transmission ofmcr-1; thus, there is a worldwide trend to limit colistin usage in animal production. However, despite lack of colistin usage in food animals in the USA,mcr-1-positiveEscherichia coliisolates were still isolated from swine. In this paper, we provided an overview of colistin usage and epidemiology ofmcr-1in food animals, and summarized the current status of mechanistic and evolutionary studies of the plasmid-mediated colistin resistance. Based on published information, we further discussed several non-colistin usage risk factors that may contribute to the persistence, transmission, and emergence of colistin resistance in an animal production system. Filling the knowledge gaps identified in this review is critical for risk assessment and risk management of colistin resistance, which will facilitate proactive and effective strategies to mitigate colistin resistance in future animal production systems.