Mechanisms of Iprovalicarb and Cycluron in Promoting Conjugative Transfer of Antibiotic Resistance Genes and Outer Membrane Vesicle-Mediated Dissemination
Horizontal gene transfer (HGT) is a major driver of the rapid dissemination of antibiotic resistance genes (ARGs) among bacteria. Non-antibiotic compounds can also promote plasmid-mediated conjugative transfer. In waterfowl farming environments, the semi-aquatic lifestyle causes water, soil, and feces to converge, creating potential hotspots for pesticide and ARG dissemination. However, the status of pesticide residues in such environments remains poorly characterized, and whether outer membrane vesicles (OMVs), an emerging ARG transmission pathway, are regulated by pesticides and respond in a manner consistent with conjugation is unclear. In this study, fecal, soil, and water samples from two waterfowl farms were screened by non-targeted metabolomics, and the high-residue fungicide iprovalicarb and herbicide cycluron were selected to investigate their effects on conjugative transfer and OMV-mediated ARG dissemination.