Antibiotic resistance often carries fitness costs, hindering our understanding of its persistence without continuous antibiotic exposure. This study investigates *mcr-1*, a gene conferring colistin resistance, in *E. coli*. It finds that regulatory evolution fine-tunes *mcr-1* expression, reducing fitness costs while maintaining high resistance. Low-cost/high-resistance *mcr-1* alleles, spread via conjugative plasmids, stabilized *mcr-1* across diverse *E. coli* strains. Regulatory mutations increased *mcr-1* stability in pig farms post-colistin ban, demonstrating how regulatory evolution and plasmid transfer can stabilize resistance despite reduced antibiotic use.
Publisher
The ISME Journal
Published On
Sep 18, 2023
Authors
Lois Ogunlana, Divjot Kaur, Liam P. Shaw, Pramod Jangir, Timothy Walsh, Stephan Uphoff, R. C. MacLean
Tags
antibiotic resistance
mcr-1
colistin
E. coli
plasmid transfer
regulatory evolution
fitness costs
Related Publications
Explore these studies to deepen your understanding of the subject.