摘要

       抗生素耐药性是一项重大的公共卫生挑战，抗生素耐药性通过环境途径的传播继续受到关注。驱动抗生素抗性基因 (ARG) 在地表水中传播的因素和城市雨水中 ARG 的来源尚未得到很好的表征。在这项研究中，在城市内陆河流中的三个风暴径流事件的整个持续时间内量化了五个 ARG（sul1、sul2、tet(O)、tet(W) 和 erm(F)）。所有五个 ARG 的风暴负荷都显着大于等效背景期间。无论 ARG 浓度是绝对浓度还是标准化为 16S rRNA 水平，测量的粪便指示菌（大肠杆菌或肠球菌）均与 sul1、sul2 或 erm(F) 没有显着相关性。大肠杆菌和肠球菌均与四环素抗性基因 tet(O) 和 tet(W) 相关。进行了下一代鸟枪宏基因组测序以更彻底地表征抗性组（即 ARG 的完整补充）并描述当前数据库中描述的所有 ARG 在风暴径流中的发生情况，以便为未来的流域监测和管理提供信息。在每个河流样本中检测到 37 到 121 种不同的 ARG，尽管 ARG 剖面在风暴中有所不同。这项研究表明，风暴驱动的 ARG 运输占整个下游负载的相当大一部分，并广泛表征了城市雨水阻力，以确定指示影响的潜在标记 ARG。

       Antibiotic resistance presents a critical public health challenge and the transmission of antibiotic resistance via environmental pathways continues to gain attention. Factors driving the spread of antibiotic resistance genes (ARGs) in surface water and sources of ARGs in urban stormwater have not been well-characterized. In this study, five ARGs (sul1, sul2, tet(O), tet(W), and erm(F)) were quantified throughout the duration of three storm runoff events in an urban inland stream. Storm loads of all five ARGs were significantly greater than during equivalent background periods. Neither fecal indicator bacteria measured (E. coli or enterococci) was significantly correlated with sul1, sul2, or erm(F), regardless of whether ARG concentration was absolute or normalized to 16S rRNA levels. Both E. coli and enterococci were correlated with the tetracycline resistance genes, tet(O) and tet(W). Next-generation shotgun metagenomic sequencing was conducted to more thoroughly characterize the resistome (i.e., full complement of ARGs) and profile the occurrence of all ARGs described in current databases in storm runoff in order to inform future watershed monitoring and management. Between 37 and 121 different ARGs were detected in each stream sample, though the ARG profiles differed among storms. This study establishes that storm-driven transport of ARGs comprises a considerable fraction of overall downstream loadings and broadly characterizes the urban stormwater resistome to identify potential marker ARGs indicative of impact.

https://www.sciencedirect.com/science/article/abs/pii/S0043135417305225