Prevalence and transmission of mobilized colistin resistance (mcr) gene in bacteria common to animals and humans

Colistin is an old antimicrobial that has been revitalized as last-resort treatment against multidrug-resistant (MDR) gram-negative bacterial infections. However, colistin has been widely used in agricultural production and veterinary medicine for decades, and the recent global dissemination of mobilized colistin resistance (mcr) genes from animals to humans seriously threats the clinical use of colistin. Most of the mcr-harboring isolates have been Enterobacteriaceae, such as Escherichia coli and Salmonella enterica which are common to animals and humans. An understanding of the origin, dissemination and transmission of mcr genes in bacteria common to animals and humans will facilitate the management of colistin use and relevant interventions to prevent further spread of resistance. This review aims to provide a comprehensive assessment of the global prevalence and transmission of mcr genes of animal and human commensal/pathogenic bacteria. •Colistin is a revitalized old antimicrobial of last-resort for the treatment of multidrug-resistant (MDR) Gram-negative bacterial infections nowadays.•The recent global dissemination of mobilized colistin resistance (mcr) genes from animals to humans seriously threats the clinical utility of colistin.•This review collected the published data of mcr genes (mcr-1 to -9) that discovered in bacteria from animals and humans, and describe the global epidemic of mcr genes, as well as prevalence and transmission of mcr in bacteria common to animals and humans (Escherichia coli, Salmonella enterica, Klebsiella pneumoniae and other bacteria).•Further perspectives of this field were also provided in the review.•Analysis the prevalence and transmission of mcr genes in human and animal common bacteria species will contribute to the management of colistin use and the prevention of colistin resistance.