摘要

       在全面的河流湿地中很少研究同时消除抗生素和抗生素抗性基因 (ARG)。在这里，我们比较了中国北京天然（野鸭湖（YL））和人工（白河（BR））河流湿地中 60 种抗生素和 27 种 ARG 的出现、丰度和去除情况。 YL湿地中抗生素的浓度为水中ND-51.9ng/L和沉积物中ND-37.9ng/g。在再生水处理厂下游的 BR 湿地中发现了显着更高的浓度（水中 ND–546ng/L 和沉积物中 ND–118ng/g）。 YL和BR湿地中ARGs在水中的丰度分别高达5.33×105和8.41×105拷贝/mL，在沉积物中分别高达1.60×107和4.67×108拷贝/g。这些结果表明，废水极大地促进了水和沉积物中抗生素和 ARG 丰度的增加。与夏季相比，由于使用率较高、衰减较慢和稀释有限，冬季发现水中抗生素含量较高。但是，夏季发现的 ARG 丰度高于冬季，这与 16S rRNA 拷贝表示的较高温度下微生物的有利生长一致。与BR湿地相比，YL湿地对抗生素和ΣARGs的去除效果更好，平均去除效率分别为70.0%和87.5%。抗生素、ARGs 和环境因素在 YL 湿地的水样中显示出很强的相关性。然而，在接收城市污水的 BR 湿地中，尽管抗生素的分布受水生环境因素的影响，但没有发现抗生素与 ARGs 之间的相关性。这些结果表明抗生素的亚抑制浓度可能会刺激天然湿地中 ARGs 的流行。

       Simultaneous elimination of antibiotics and antibiotic resistance genes (ARGs) is rarely investigated in full-scale riverine wetlands. Here, we compared the occurrence, abundance, and removal of 60 antibiotics and 27 ARGs in natural (Yeya Lake (YL)) and constructed (Bai River (BR)) riverine wetlands in Beijing, China. The concentrations of antibiotics in YL wetland were ND–51.9 ng/L in water and ND–37.9 ng/g in sediments. Significantly higher concentrations were found in BR wetland (ND–546 ng/L in water and ND–118 ng/g in sediments), which locates at the downstream of a reclaimed water treatment plant. The abundances of ARGs in YL and BR wetlands were up to 5.33 × 105 and 8.41 × 105 copies/mL in water, and 1.60 × 107 and 4.67 × 108 copies/g in sediments, respectively. These results suggest that wastewater greatly contributes to the elevated abundance of antibiotics and ARGs in both water and sediments. Compared to summer, higher levels of antibiotics in water were found in winter due to the higher usage, slower attenuation and the limited dilution. But higher abundances of ARGs were found in summer than in winter, in accordance with the favored microbial growth at higher temperature as denoted by copies of 16S rRNA. Compared to BR wetland, YL wetland achieved better removal of antibiotics and ΣARGs, with average removal efficiencies of 70.0% and 87.5%. Antibiotics, ARGs and environmental factors showed strong correlations in water samples from YL wetland. However, in BR wetland that receives urban wastewater effluents, no correlation between antibiotics and ARGs was found although the distribution of antibiotics was affected by aquatic environmental factors. These results indicate that subinhibitory concentrations of antibiotics may stimulate the prevalence of ARGs in natural wetlands.

https://www.sciencedirect.com/science/article/abs/pii/S0048969719305224