摘要

       抗生素抗性基因 (ARG) 目前被认为是新出现的环境污染物。医院和城市污水是接收淡水体的 ARG 的重要来源。我们研究了处理废水点源附近淡水湖沉积物中不同 ARG（sul1、sul2、tet(B)、tet(M)、tet(W) 和 qnrA）的空间分布。瑞士日内瓦湖维迪湾的 ARG 污染使用实时 PCR 进行量化，并与总汞 (THg) 进行比较，总汞 (THg) 是一种常见的颗粒结合无机污染物，具有已知的自然背景水平。使用地质统计工具对湖泊沉积物中调查的污染物进行二维绘图显示，污水排放点附近 ARGs 的总丰度和相对丰度比在远程参考地点（湖中心）测得的水平高 200 倍，并且随距离呈指数下降。在不同 ARG 的空间分布中观察到类似的趋势，而 ARG 和 THg 的分布仅适度相关，表明这些污染物或其他 ARG 污染源的运输和归宿存在差异。 ARG 污染的空间格局和支持数据表明，颗粒相关废水细菌的沉积而不是例如重金属的共同选择是沉积物 ARG 污染的主要原因。

       Antibiotic-resistance genes (ARGs) are currently discussed as emerging environmental contaminants. Hospital and municipal sewage are important sources of ARGs for the receiving freshwater bodies. We investigated the spatial distribution of different ARGs (sul1, sul2, tet(B), tet(M), tet(W) and qnrA) in freshwater lake sediments in the vicinity of a point source of treated wastewater. ARG contamination of Vidy Bay, Lake Geneva, Switzerland was quantified using real-time PCR and compared with total mercury (THg), a frequently particle-bound inorganic contaminant with known natural background levels. Two-dimensional mapping of the investigated contaminants in lake sediments with geostatistical tools revealed total and relative abundance of ARGs in close proximity of the sewage discharge point were up to 200-fold above levels measured at a remote reference site (center of the lake) and decreased exponentially with distance. Similar trends were observed in the spatial distribution of different ARGs, whereas distributions of ARGs and THg were only moderately correlated, indicating differences in the transport and fate of these pollutants or additional sources of ARG contamination. The spatial pattern of ARG contamination and supporting data suggest that deposition of particle-associated wastewater bacteria rather than co-selection by, for example, heavy metals was the main cause of sediment ARG contamination.

https://www.nature.com/articles/ismej20148