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 reviewaims to provide a comprehensive assessment of the global prevalence and transmission of mcr genes of animal and human commensal/pathogenic bacteria.