Plastisphere-Derived Extracellular Vesicles: Hotspots for Antibiotic Resistance Genes and Virulence Factor Genes

Extracellular vesicles (EVs) are produced by a wide range of microorganisms, serving as a unique reservoir and transporter for antibiotic resistance genes (ARGs) and virulence factor genes (VFGs). While the plastisphere is recognized as a hotspot for ARGs and potential pathogens, it remains unclear whether pathogenic bacteria in the plastisphere release ARGs and VFGs within EVs, with potential to amplify health risks. We investigated the presence of ARGs and VFGs within EVs and their microbial origins in the plastisphere via a long-term controlled microcosm experiment. Our results reveal that the abundance of EVs in the plastisphere can reach up to 1011/m2. Various ARGs and mobile genetic elements (MGEs) were detected in plastisphere-derived EVs, showing a hierarchical enrichment along the environment-plastisphere-EVs pathway. These EVs-releasing microbes in the plastisphere have been found in plastic samples across the globe. Some potential pathogens associated with EVs were enriched in the plastisphere and displayed a strong correlation with VFGs. Additionally, we observed that heavy metal pollution significantly enhances the presence of ARGs in plastisphere-derived EVs. Interestingly, when exposed to heavy metal stress, EVs derived from plastispheres incubated in soil and water showed distinct alterations in ARGs driven by different underlying mechanisms. Our findings shed light on the prevalence of ARGs, and the pathogenic characteristics of EVs in the plastisphere, highlighting the potential dissemination of ARGs and pathogenicity through plastisphere EVs.