摘要
      抗生素向河流环境的排放会影响水生生态系统的功能，并导致抗生素耐药性的发展。本文分析了珠江水系两条大河中44种抗生素和18种抗生素抗性基因（ARGs）的图谱。此外，还对抗生素造成的生态毒性和耐药性选择的风险进行了评估。与水库相比，靠近城市和畜牧区的河段含有更多的抗生素和ARGs。在水中发现了抗生素的季节性变化（旱季更高）和相对ARGs（通过16S rRNA基因标准化，雨季更高），但在沉积物中没有发现。磺酰胺抗性基因是河水和沉积物中最普遍的ARGs。抗生素浓度与水中ARG的丰度相关，表明抗生素在ARG的传播中起着关键作用。此外，土霉素是最丰富的抗生素，水中和沉积物中的浓度分别高达2030纳克/升和2100纳克/克，对耐药性选择的风险最高。预计土霉素、四环素和磺胺甲恶唑对水生生物的生态毒性更大，而氧氟沙星、恩诺沙星、诺氟沙星、金霉素、土霉素和四环素在沉积物中构成生态毒性风险。畜牧业活动频繁的南柳江受到抗生素和ARGs的污染，面临着较高的生态毒理学和耐药性选择风险。总的来说，这些发现反映了人类活动对大型河流流域抗生素耐药性传播的影响。
abstract
Emission of antibiotics into riverine environments affects aquatic ecosystem functions and leads to the development of antibiotic resistance. Here, the profiles of forty-four antibiotics and eighteen antibiotic resistance genes (ARGs) were analyzed in two large rivers of the Pearl River System. In addition, the risks of ecotoxicity and resistance selection posed by the antibiotics were estimated. As compared to the reservoirs, the river sections close to the urban and livestock areas contained more antibiotics and ARGs. Seasonal variations of antibiotics (higher in the dry season) and relative ARGs (normalized by 16S rRNA gene, higher in the wet season) were found in the water, but not in the sediment. Sulfonamide resistance genes were the most prevalent ARGs in both river water and sediment. Antibiotic concentration was correlated with ARG abundance in the water, indicating that antibiotics play a critical role in ARG spread. In addition, oxytetracycline was the most abundant antibiotic with concentrations up to 2030 ng/L in the water and 2100 ng/g in the sediment respectively, and posed the highest risks for resistance selection. Oxytetracycline, tetracycline and sulfamethoxazole were expected to be more ecotoxicologically harmful to aquatic organisms, while ofloxacin, enrofloxacin, norfloxacin, chlortetracycline, oxytetracycline and tetracycline posed ecotoxicological risks in the sediment. The Nanliujiang river with intensive livestock activities was contaminated by antibiotics and ARGs and faced high ecotoxicological and resistance selection risks. Collectively, these findings reflect the impacts of anthropogenic activities on the spread of antibiotic resistance in large river basins.

https://www.sciencedirect.com/science/article/abs/pii/S0269749122011927