摘要
      雨水中含有大量抗生素耐药性基因（ARGs）和耐药性细菌（ARB），可能导致严重感染，对公众健康构成潜在威胁。然而，在城市水生态系统中，雨水如何通过垂直基因转移（VGT）或水平基因转移（HGT）对ARG剖面以及ARG和细菌之间的动态相互作用做出贡献，目前还没有定论。在本研究中，通过高通量定量PCR、16S rRNA基因扩增子测序和SourceTracker在极端降水事件（132.1 mm）发生前、发生后和恢复过程中的应用，研究了中国云当泻湖ARGs的分布、宿主群落以及ARGs来源和群落组装过程。根据SourceTracker和NMDS分析，沉淀后一天泻湖表面水中的ARG和细菌群落主要由污水处理厂的进水和出水贡献。然而，在降水后11天，污水处理厂对ARG社区的贡献很小，这表明风暴通过引入来自点源和非点源的ARG、MGE和ARB，如下水道溢流和土地施用的粪肥，提高了ARG水平。基于一种新的微生物网络分析框架，ARG与MGE或细菌之间的积极生物相互作用在沉淀后一天的贡献最高，表明VGT和HGT促进了ARG的传播。降水后11天，微生物网络被解构，这表明雨水做法（如潮汐闸门打开、引水渠和抽水）缓解了ARGs的传播。这些结果促进了我们对城市雨水径流中与其来源相关的ARG的分布和运输的理解。
Abstract
Antibiotic-resistance genes (ARGs) and resistant bacteria (ARB) are abundant in stormwater that could cause serious infections, posing a potential threat to public health. However, there is no inference about how stormwater contributes to ARG profiles as well as the dynamic interplay between ARGs and bacteria via vertical gene transfer (VGT) or horizontal gene transfer (HGT) in urban water ecosystems. In this study, the distribution of ARGs, their host communities, and the source and community assembly process of ARGs were investigated in Yundang Lagoon (China) via high-throughput quantitative PCR, 16S rRNA gene amplicon sequencing, and application of SourceTracker before, after and recovering from an extreme precipitation event (132.1 mm). The abundance of ARGs and mobile genetic elements (MGEs) was the highest one day after precipitation and then decreased 2 days after precipitation and so on. Based on SourceTracker and NMDS analysis, the ARG and bacterial communities in lagoon surface water from one day after precipitation were mainly contributed by the wastewater treatment plant (WWTP) influent and effluent. However, the contribution of WWTP to ARG communities was minor 11 days after the precipitation, suggesting that the storm promoted the ARG levels by introducing the input of ARGs, MGEs, and ARB from point and non-point sources, such as sewer overflow and land-applied manure. Based on a novel microbial network analysis framework, the contribution of positive biological interactions between ARGs and MGEs or bacteria was the highest one day after precipitation, indicating a promoted VGT and HGT for ARG dissemination. The microbial networks deconstructed 11 days after precipitation, suggesting the stormwater practices (e.g., tide gate opening, diversion channels, and pumping) alleviated the spread of ARGs. These results advanced our understanding of the distribution and transport of ARGs associated with their source in urban stormwater runoff.

https://www.sciencedirect.com/science/article/pii/S0160412022003841