Hou Liyuan, Zhang Lanping, Li Furun, Huang Sijun, Yang Jun, Ma Cong, Zhang Duanxin, Yu Chang-Ping, Hu Anyi
CAS Key Laboratory of Urban pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; Department of Chemistry, SUNY College of Environmental Science and Forestry, Syracuse, NY 13210, USA.
CAS Key Laboratory of Urban pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; University of Chinese Academy of Sciences, Beijing 100049, China.
J Hazard Mater. 2021 Feb 5;403:124008. doi: 10.1016/j.jhazmat.2020.124008. Epub 2020 Sep 18.
The occurrence, dissemination and assembly processes of antibiotic resistance genes (ARGs) in urban water ecosystems are far from being understood. Here, we examined the diversity and abundance of ARGs in urban water ecosystems including landscape ponds, drinking water reservoirs, influents (IFs) and effluents (EFs) of wastewater treatment plants of a coastal city, China through high-throughput quantitative PCR. A total of 237 ARGs were identified, where multidrug, aminoglycoside and beta-lactamase resistance genes were the most abundant. Urban ponds had a comparatively high diversity and large numbers of shared ARGs with IFs and EFs. The average absolute abundance of ARGs (1.38 × 10 copies/mL) and mobile genetic elements (MGEs) (4.19 × 10 copies/mL) in ponds were only one order of magnitude lower than those of IFs, but higher than those of EFs and reservoirs. Stochastic processes dominated the ARG community assembly in IFs and ponds due to the random horizontal gene transfer caused by MGEs. These results imply that urban ponds are hotspots of ARGs. We further identified 25, 3, and 11 indicator ARGs for tracing the ARG contamination from IFs, EFs and ponds, respectively. Our study represents the first to highlight the role of urban ponds in the dissemination of ARGs.
城市水生态系统中抗生素抗性基因（ARGs）的发生、传播和组装过程仍远未被了解。在此，我们通过高通量定量PCR检测了中国沿海某城市水生态系统中ARGs的多样性和丰度，该水生态系统包括景观池塘、饮用水水库、污水处理厂的进水（IFs）和出水（EFs）。共鉴定出237种ARGs，其中多药、氨基糖苷和β-内酰胺酶抗性基因最为丰富。城市池塘具有较高的多样性，并且与进水和出水共享大量的ARGs。池塘中ARGs（1.38×10拷贝/毫升）和可移动遗传元件（MGEs）（4.19×10拷贝/毫升）的平均绝对丰度仅比进水低一个数量级，但高于出水和水库。由于MGEs引起的随机水平基因转移，随机过程主导了进水和池塘中ARG群落的组装。这些结果表明城市池塘是ARGs的热点区域。我们还分别鉴定出25种、3种和11种指示性ARGs，用于追踪进水、出水和池塘中的ARG污染。我们的研究首次突出了城市池塘在ARGs传播中的作用。
