摘要

      众所周知，雨水径流会增加城市河流中的细菌负荷。然而，人们对其对城市流域抗生素耐药基因（ARGs）的影响知之甚少。本研究旨在描述城市分水岭不同环境分区的ARG组成，并量化在潮湿天气条件下，微生物和ARG对城市河流的贡献。鸟枪基因组分析结果表明，湿气流中ARG的丰度明显高于基流。多药耐药基因是环境样品中最常见的ARG类型。万古霉素抗性基因在路基土和扫街样中含量丰富。使用SourceTracker进行的分析估计，在潮湿天气流动期间，雨水排放口的水是城市河流中微生物（54-57%）和ARGs（82-88%）的最大贡献者。此外，街道清扫的结果表明，街道冲洗是已知的最大贡献者（41-45%）和ARGs（92-96%）在暴雨排水口水。pantoa和Pseudomonas与ARGs的数量最高相关，并且在与雨水相关的样本中最为丰富。本研究的结果可以增进我们对城市河流中ARGs的了解，这是连接环境ARGs与公众的重要媒介。

       Stormwater runoff has been known to cause increases in bacterial loadings in urban streams. However, little is known about its impacts on antibiotic resistance genes (ARGs) in urban watersheds. This study was performed to characterize the ARG composition of various environmental compartments of an urban watershed and to quantify their contributions of microbes and ARGs to an urban stream under wet weather conditions. Shotgun metagenomic results showed that the ARG abundance in wet weather flow was significantly higher than in base flow. Multidrug resistance genes were the most common ARG type across environmental samples. Vancomycin resistance genes were abundant in embankment soil and street sweeping samples. Analyses using SourceTracker estimated storm drain outfall water to be the biggest contributor of microbes (54-57%) and ARGs (82-88%) in the urban stream during wet weather flows. Furthermore, results on street sweepings showed that wash-off from streets was the biggest known contributor of microbes (41-45%) and ARGs (92-96%) in storm drain outfall water. Pantoea and Pseudomonas were associated with the highest numbers of ARGs and were most abundant in stormwater-related samples. Results from this study can advance our knowledge about ARGs in urban streams, an important medium linking environmental ARGs to the general public.

       https://www.sciencedirect.com/science/article/pii/S0269749118316403?via%3Dihub