The fate of antibiotic resistance genes and their correlation with microbial communities and wastewater quality/parameters in a wastewater treatment plant under different seasons

Wastewater treatment plants (WWTPs) are the hardest hit areas of antibiotic resistance genes (ARGs) pollution. As an emerging contaminant, ARGs seriously threaten ecological, human, and livestock safety. It is research interest to understand the potential relationship between ARGs, wastewater quality/parameters, and microbial communities. Herein, we compared that the variation of ARGs, wastewater quality/parameters, and microbial communities along the whole treatment processes in the WWTP in summer and winter. Results showed that ARGs abundance in summer is higher than that in winter, and the removal efficiency of ARGs varies with season. In summer, ARGs abundance had a significant correlation with phosphorus concentration, but in winter changed to the content of heavy metals (HM). Meanwhile, the dominant bacteria genera and their abundance were distinct in different seasons. The network analysis illustrated that ARGs are correlated with bacterial genera. Throughout this study, we found that wastewater quality/parameters and microbial community play a key role in the formation of ARGs, and the relationship among them is driven by seasonal variation. This work will help to provide a direction for optimizing wastewater treatment processes and controlling the spread of ARGs from the WWTPs to aquatic environment.