Plasmids promote antimicrobial resistance through insertion sequence-mediated gene inactivation

This study shows that plasmids—mobile DNA elements that move between bacteria—can accelerate the development of antimicrobial resistance (AMR) in more ways than previously recognized. Researchers found that the plasmid pOXA-48 in Klebsiella pneumoniae contains insertion sequences (IS1) that can disrupt bacterial genes, which in turn increases the bacteria’s ability to become resistant to multiple antibiotics. Analyses of genomic databases confirmed that this IS-mediated gene inactivation is a widespread mechanism of resistance evolution. The findings demonstrate that conjugative plasmids contribute to AMR not only by spreading resistance genes between bacteria, but also by actively driving new resistance through gene disruption.