The mcr-1 gene–a gene that makes bacteria resistant to colistin, an antibiotic of last resort, and that is transferrable between bacteria–has been found in a wide variety of strains of Escherichia coli in China following widespread use of colistin in agriculture.
As China prepares to introduce the drug for the first time in human medicine, two new studies published in The Lancet Infectious Diseases provide evidence of how widely the mcr-1 gene has spread to bacteria in clinical settings, including to a minority already resistant to the carbapenem class of antibiotics, and highlight the need for caution and careful prescribing when the country introduces colistin.

