摘要
      抗生素耐药性是一种公共健康威胁，抗生素耐药性基因（ARGs）扩散到水生环境中加剧了这一威胁。城市雨水径流已被认为是细胞内ARGs（iARGs）输送到接收环境中的来源和机制。然而，细胞外ARGs（eARGs）在雨水中的流行率和行为尚待考虑。本研究量化了基流和暴雨流条件下的四种iARG和eARG。城市雨水径流被发现是所有检查的ARG的来源，所有iARG和两种eARG（ermF和tetC）的绝对浓度在基流和暴雨流之间显著增加（p<0.05）。还调查了三个季节雨水径流中iARGs和eARGs的发生情况，以区分时间趋势。所有eARG都在秋季最为丰富，而iARG并没有表现出一致的季节性趋势。接下来，通过针对四个采样位置，包括来自路边雨水入口和雨水排放口的直接径流，以及两个接收环境，Menomonee河和密歇根湖，阐明了ARG的空间模式。就基流和暴雨流之间ARG浓度的百分比增加而言，雨水对排水口位置的影响最大，其中iARG和eARG平均分别增加了16%和12.3%。iARGs和eARGs之间季节和空间趋势的变化表明，ARGs进入环境的来源和运输机制存在差异。此外，这项研究的结果表明，在确定雨水径流引起的抗生素耐药性威胁时，eARGs是需要考虑的相关污染物。
Abstract
Antibiotic resistance is a public health threat that is exacerbated by the dispersion of antibiotic resistance genes (ARGs) into aquatic environments. Urban stormwater runoff has been recognized as a source of and a mechanism by which intracellular ARGs (iARGs) can be transported into receiving environments. The prevalence and behavior of extracellular ARGs (eARGs) in stormwater, however, has yet to be considered. This study quantified four iARGs and eARGs under baseflow and stormflow conditions. Urban stormwater runoff was found to be a source of all the ARGs examined, with the absolute concentration of all iARGs and two eARGs (ermF and tetC) increasing significantly (p < 0.05) between baseflow and stormflow. The occurrence of iARGs and eARGs in stormwater runoff was also investigated across three seasons to differentiate temporal trends. All eARGs were found to be most abundant in the fall, while the iARGs did not display a consistent seasonal trend. Following, spatial patterns of the ARGs were elucidated by targeting four sampling locations, including direct runoff from a curbside storm inlet and a stormwater outfall, and two receiving environments, the Menomonee River and Lake Michigan. Stormwater was found to have the largest impact, in terms of the percent increase in ARG concentrations between baseflow and stormflow, on the outfall location where on average the iARGs and eARGs increased 16% and 12.3%, respectively. The variability in seasonal and spatial trends between the iARGs and eARGs suggests a difference in sources and transport mechanisms of the ARGs into the environment. Moreover, the results of this study revealed that eARGs are relevant contaminants to consider when determining the threat of antibiotic resistance originating from stormwater runoff.

https://pubs.rsc.org/en/content/articlehtml/2022/va/d2va00065b