Colistin is an antibiotic of last resort for the treatment of infections caused by extremely multidrug-resistant Gram-negative bacteria. The recent emergence and global spread of the mobile colistin resistance gene mcr-1 among many bacterial species in different environments poses a significant public health threat. However, the workings and success of mcr-1 as a resistance factor have not been fully understood. Led by scientists of the German Center for Infection Research (DZIF), a study recently published in the journal Microbiology Spectrum provides crucial answers on how acquiring mcr-1 benefits bacteria and explores an approach to eliminate mcr-1 and its transmission vectors.