Preprint finds redox stress sharply elevates mutagenesis during bacterial horizontal gene transfer

A preprint posted to bioRxiv investigates how oxidative and other redox stresses affect mutation rates specifically during horizontal gene transfer in bacteria — a route by which antibiotic resistance genes spread between organisms. The researchers developed a protocol exploiting single-stranded DNA (ssDNA), which is both highly susceptible to chemical damage and largely inaccessible to most DNA repair pathways, as a reporter system for measuring redox-induced mutagenesis.

The study finds that redox stress agents substantially increase mutation rates during gene transfer events and that different redox agents leave characteristic mutational and metabolic footprints — patterns in the types and locations of mutations that may serve as signatures linking specific environmental stresses to resistance emergence. The authors suggest this could help explain why antibiotic resistance evolves more rapidly in environments rich in reactive oxygen species, such as those encountered during host infection or antibiotic treatment itself.

Understanding the mutational dynamics of horizontal gene transfer is relevant to antimicrobial resistance research, as it connects environmental stress conditions to the evolutionary processes generating resistance diversity. The preprint has not yet undergone peer review, and findings relating to specific mutational footprints will require further validation across diverse bacterial species and genetic backgrounds.