A small molecule that inhibits the evolution of antibiotic resistance

Antimicrobial resistance (AMR) rapidly develops against almost all available therapeutics. New antibiotics target essential processes in bacteria but fail to address the root of the problem: mutagenesis and evolution. We recently proposed that inhibiting the molecular mechanisms underlying bacterial evolution is the ultimate solution to preventing AMR development. Here, we describe the first compound that inhibits the occurrence and progression of AMR by directly targeting a highly conserved bacterial evolvability factor, Mfd. We previously found that this RNA polymerase-associated translocase is required for rapid AMR development across highly divergent pathogens. Through an in vivo screen, we identified 43 potential Mfd-inhibiting compounds. Here we present on target validation, biochemical characterization, and in vivo efficacy studies of a lead compound, referred to as ARM-1. ARM-1 binds Mfd and modulates its RNA polymerase interaction. Inhibition of Mfd activity by ARM-1 delays the development of mutations and resistance acquisition, both in pure culture and during infection. Importantly, our data show that this compound prevents the evolution of AMR across highly divergent pathogens, including Pseudomonas aeruginosa, Staphylococcus aureus, Listeria monocytogenes, and Salmonella enterica serovar Typhimurium. The novel compound we present here has the potential to develop into a clinically useful "anti-evolution" drug. This work demonstrates that the molecular mechanisms of evolution are pharmaceutically targetable, and that this strategy could help prevent AMR development.