Transfer and persistence of plasmids in microbial communities of wastewater treatment plant

Despite the near-ubiquity of plasmids in bacterial populations and the profound contribution of gene transfer to the current epidemic of antibiotic-resistant infections, the long-term persistence of plasmids in microbial communities are poorly understood. While long-term plasmid stability in single species/strain often cannot be guaranteed without evolutionary adaptation, multi-species context of a microbial community might provide sufficient chances for inter-species/strain interaction, creating dynamic plasmid transfer and persistence profiles and thereby promoting access to plasmid at community level. In this study, we utilizes for the first time to our knowledge a complex WWTP derived environmental community to investigate IncP-1 plasmid pKJK5 transfer and persistence by time-series experiments with environmental and human relevance. Once initiating plasmid transfer, broad scale plasmid-host interaction arouse quickly and held through time series, contributing to highly dynamic plasmid-persistence profiles at community level. Heterogenous fitness effect even with frequent positive fitness, dramatically facilitated plasmid persistence across community even counteracted loss of permissive member. Results of this study provided a first unique insight into robust community-level plasmid persistence, and highlighted its significant role in plasmid-mediated ARG dissemination across diverse environments.