摘要

      废水处理厂、陆地农业和水产养殖等点源可能向水生生态系统释放抗生素残留、抗生素抗性细菌和抗生素抗性基因（ARGs）。然而，将环境中的ARG丰度归因于特定来源的定量研究还很缺乏。这项研究的目的是评估淡水鳟鱼养殖场在释放和向环境传播ARGs方面的作用。在智利南部，随着时间的推移，从五个虹鳟养殖场的上游和下游采集了沉积物样本。采用微流控定量聚合酶链反应（pcr）方法对不同耐药机制的ARG阵列进行定量，并采用主成分分析（PCA）和线性混合回归模型对数据进行分析。还进行了调查，以获取有关农场管理做法的信息，包括抗生素使用情况。这些农场使用氟苯尼考和土霉素，尽管使用率不同。共分析93个样品。在主成分分析中，，（A），（B），（C），（W）和组合在一起。与上游相比，农场下游的、和多个基因的丰度在统计学上显著增加，并且保留池的ARG丰度在每个位置都最高。抗生素耐药基因水平在农场下游132.7米处恢复到基线水平。虽然本研究结果显示鳟鱼养殖场对邻近环境中ARGs的存在有影响，但它们对ARGs传播的贡献程度尚不清楚，值得进一步研究。

       Point sources such as wastewater treatment plants, terrestrial agriculture, and aquaculture may release antibiotic residues, antibiotic resistant bacteria, and antibiotic resistance genes (ARGs) into aquatic ecosystems. However, there is a lack of quantitative studies attributing environmental ARG abundance to specific sources. The goal of this study was to evaluate the role of freshwater trout farms in the release and dissemination of ARGs into the environment. Sediment samples upstream and downstream from five rainbow trout farms were collected over time in southern Chile. A microfluidic quantitative polymerase chain reaction approach was used to quantify an ARG array covering different mechanisms of resistance, and data were analyzed using principal component analysis (PCA) and linear mixed regression models. Surveys were also conducted to obtain information about management practices, including antibiotic use, at the farms. Florfenicol and oxytetracycline were used at these farms, although at different rates. A total of 93 samples were analyzed. In the PCA, , , , , (A), (B), (C), (W), and grouped together. A statistically significant increase in abundance of , , , and several genes was found downstream from the farms compared with upstream sites, and retention ponds had the highest ARG abundance at each site. Antibiotic resistance gene levels returned to baseline at an average distance of 132.7 m downstream from the farms. Although results from this study indicate an influence of trout farms on the presence of ARGs in the immediate environment, the extent of their contribution to ARG dissemination is unknown and deserves further investigation.

        https://acsess.onlinelibrary.wiley.com/doi/abs/10.2134/jeq2018.12.0431