Extracellular vesicles drive stress-induced antibiotic resistance spread in soil

Antimicrobial resistance threatens millions of lives annually, yet its acceleration by non-antibiotic pollutants remains poorly understood. Artificial sweeteners, now ubiquitous in soils and waters, are known individually to promote conjugative transfer of resistance genes, but real environments contain complex mixtures whose collective impact is unknown. Extracellular vesicles (EVs) released by stressed bacteria serve as protected, long-range vectors for antibiotic resistance genes (ARGs), yet whether sweetener diversity modulates this pathway has never been tested. Here we show that increasing artificial-sweetener diversity dramatically enriches ARGs, virulence factors and mobile genetic elements inside soil-derived Evs, driving compositional shifts in 30.5% of EV-associated genera while leaving the bulk microbiome largely undisturbed. EVs originate from a small, fast-growing Pseudomonadota subset that upregulates vesicle-biogenesis genes in response to oxidative and membrane stress; these vesicles selectively package chromosomal resistance traits and transfer phenotypic resistance to recipient Escherichia coli. This stress-induced decoupling reveals EVs as rapid, hidden mediators of resistome mobilization that community-level surveys miss. By demonstrating that pollutant diversity itself drives resistance dissemination through nanoscale vectors, our findings establish EVs as a critical new indicator within the One Health framework and call for revised environmental risk models that account for chemical complexity rather than single-compound exposures.