Macrophage-mediated antibiotic evasion and competitive dominance of mcr-3-carrying Escherichia coli

Mobile colistin resistance genes reduce the effectiveness of polymyxins, which are often used as last-line antibiotics. Among them, mcr-3 has continued to increase globally even after colistin use declined. This trend suggests that mcr-3 may provide selective advantages beyond antibiotic resistance. The research reveals macrophage-mediated mechanisms enabling mcr-3-carrying E. coli to evade immune responses and achieve competitive dominance in mixed bacterial populations.