摘要
      未经处理的联合污水（旁路）通常在暴雨期间由污水处理厂排放到接收河流，在那里它可能会导致接收水中抗生素耐药性基因（ARGs）和多重耐药性风险因素（多重耐药性细菌和多重耐药性基因组决定簇（MGD））的水平增加。其他污染源，如土壤径流和重新悬浮的河流沉积物，也可能在暴雨事件中发挥作用。在这里，我们报告了基于雨水事件的采样活动，以确定旁路、处理过的污水和接收河流中ARGs和多阻力风险因素的时间动态，以及集水区土壤和地表沉积物的补充数据。指标ARG（qPCR）和抗性（宏基因组学揭示的ARG图谱）均表明，旁路是暴雨事件期间河流中ARG水平升高的主要原因。此外，我们首次表明，在暴雨事件下，暴露于旁路传播的多抗性风险因素的风险增加，并且这些MGD中的许多是质粒相关的，因此具有潜在的流动性。此外，雨水事件发生后，受纳水中的阻力风险因素升高持续了一段时间（长达22小时），这可能是由于集水区分散溢流的输入。这表明，在解释暴露于基于事件的污染的耐药性风险时，应考虑时间动态。我们提出，减少废水处理厂的旁路可能是减少抗生素耐药性传播的一个重要干预选择。
Abstract
Untreated combined sewage (bypass) is often discharged by wastewater treatment plants to receiving rivers during stormwater events, where it may contribute to increased levels of antibiotic resistance genes (ARGs) and multi-resistance risk factors (multi-resistant bacteria and multi-resistance genomic determinants (MGDs)) in the receiving water. Other contamination sources, such as soil runoff and resuspended river sediment could also play a role during stormwater events. Here we report on stormwater event-based sampling campaigns to determine temporal dynamics of ARGs and multi-resistance risk factors in bypass, treated effluent, and the receiving river, as well as complimentary data on catchment soils and surface sediments. Both indicator ARGs (qPCR) and resistome (ARG profiles revealed by metagenomics) indicated bypass as the main contributor to the increased levels of ARGs in the river during stormwater events. Furthermore, we showed for the first time that the risk of exposure to bypass-borne multi-resistance risk factors increase under stormwater events and that many of these MGDs were plasmid associated and thus potentially mobile. In addition, elevated resistance risk factors persisted for some time (up to 22 h) in the receiving water after stormwater events, likely due to inputs from distributed overflows in the catchment. This indicates temporal dynamics should be considered when interpreting the risks of exposure to resistance from event-based contamination. We propose that reducing bypass from wastewater treatment plants may be an important intervention option for reducing dissemination of antibiotic resistance.

https://www.sciencedirect.com/science/article/pii/S0043135421010216