摘要
      人们越来越担心抗生素耐药性在环境中出现和传播的风险。在这里，我们评估了污水处理厂废水对河流沉积物中抗生素耐药性影响的时空模式。为此，在三个位置收集了受污水处理厂废水影响的三个流域的沉积物样本，这些流域处于潮湿（高水位期）和干燥（低水位期）水文条件下：（i）污水处理厂上游；（ii）污水处理厂污水排放点（污水排放口）；以及（iii）污水处理厂下游（污水排放口下游500米处）。对沉积物样品中9个抗生素抗性基因（ARGs）、3个移动遗传元件（MGE）基因和4个金属抗性基因（MRGs）的绝对丰度和相对丰度进行了定量，并对沉积物和水样中的各种物理化学参数、金属含量和抗生素浓度进行了定量。在沉积物中，在下游采样点与上游采样点观察到大多数基因的相对丰度明显更高。沉积物样品中ARG绝对丰度和相对丰度的季节性变化（枯水期与枯水期的值较高）。化学数据显示，污水处理厂的废水是河流生态系统中抗生素和金属污染的来源。观察到的ARG和MGE基因相对丰度之间的正相关性指出了水平基因转移在抗生素耐药性传播中的作用。必须实施考虑时空模式的监测计划，以正确评估河流生态系统中与污水处理厂相关的新兴污染物的环境命运。
Abstract
There is a growing concern about the risk of antibiotic resistance emergence and dissemination in the environment. Here, we evaluated the spatio-seasonal patterns of the impact of wastewater treatment plant (WWTP) effluents on antibiotic resistance in river sediments. To this purpose, sediment samples were collected in three river basins affected by WWTP effluents in wet (high-water period) and dry (low-water period) hydrological conditions at three locations: (i) upstream the WWTPs; (ii) WWTP effluent discharge points (effluent outfall); and (iii) downstream the WWTPs (500 m downriver from the effluent outfall). The absolute and relative abundances of 9 antibiotic resistance genes (ARGs), 3 mobile genetic element (MGE) genes, and 4 metal resistance genes (MRGs) were quantified in sediment samples, as well as a variety of physicochemical parameters, metal contents, and antibiotic concentrations in both sediment and water samples. In sediments, significantly higher relative abundances of most genes were observed in downstream vs. upstream sampling points. Seasonal changes (higher values in low-water vs. high-water period) were observed for both ARG absolute and relative abundances in sediment samples. Chemical data revealed the contribution of effluents from WWTPs as a source of antibiotic and metal contamination in river ecosystems. The observed positive correlations between ARG and MGE genes relative abundances point out to the role of horizontal gene transfer in antibiotic resistance dissemination. Monitoring plans that take into consideration spatio-temporal patterns must be implemented to properly assess the environmental fate of WWTP-related emerging contaminants in river ecosystems.

https://www.sciencedirect.com/science/article/pii/S026974912202098X