摘要
      更好地了解潜流人工湿地中磺酰胺类抗生素抗性基因（ARGs）分布的时空动力学和影响因素，对于提高ARGs的去除效率至关重要。研究了磺酰胺类ARGs在垂直向上流潜流人工湿地（VUSFCW）中的时空动力学。结果表明，ARGs的绝对丰度呈现出底层>中层>顶层的趋势。ARGs的相对丰度从底层到中层显著降低，但在顶层增加。底层是去除ARG的主要阶段。夏季各点ARGs的绝对丰度明显高于冬季。基于ARGs的时空分布，利用偏最小二乘路径分析模型探讨了ARGs动态变化的内在机制。结果表明，物理化学因素、微生物和抗生素主要通过移动遗传元素间接影响ARGs的时空分布。物理化学因素、微生物和抗生素对ARGs时空分布的间接影响系数分别为0.505、0.221和0.98。MGE对ARGs时空分布的直接影响系数为0.895。网络分析结果表明，夏季ARGs的潜在宿主物种比冬季更丰富。磺酰胺ARGs对潜在宿主的选择方式是非特异性的。在VUSFCW中存在磺酰胺ARGs感染病原体的风险。幸运的是，VUSFCW已被证明能有效降低ARGs的绝对丰度和携带ARGs病原体的潜在风险。这些发现为有效降低ARGs的威胁提供了模型模拟和理论依据。
Abstract
A better understanding of the spatiotemporal dynamics and influencing factors of sulfonamide antibiotic resistance genes (ARGs) distribution in subsurface flow constructed wetlands is essential to improve the ARGs removal efficiency. The spatiotemporal dynamics of sulfonamide ARGs were explored in the vertical upflow subsurface flow constructed wetland (VUSFCW). The results showed that the absolute abundance of ARGs presented a trend of bottom layer > middle layer > top layer. The relative abundance of ARGs decreased significantly from the bottom layer to the middle layer, but increased in the top layer. The bottom layer was the main stage to remove ARGs. The absolute abundance of ARGs at each point in summer was significantly higher than that in winter. Based on the spatiotemporal distribution of ARGs, the internal mechanism of ARGs dynamic change was explored by the partial least square path analysis model. The results showed that physical-chemical factors, microorganisms and antibiotics indirectly affected the spatiotemporal distribution of ARGs mainly through mobile genetic elements. The indirect influence coefficients of physical-chemical factors, microorganisms and antibiotics on the spatiotemporal distribution of ARGs were 0.505, 0.221 and 0.98 respectively. The direct influence coefficient of MGEs on the spatiotemporal distribution of ARGs was 0.895. The results of network analysis showed that the potential host species of ARGs in summer were more abundant than those in winter. The selection mode of sulfonamide ARGs to potential hosts was nonspecific. There is a risk of sulfonamide ARGs infecting pathogens in VUSFCW. Fortunately, VUSFCW has proven effective in reducing the absolute abundance of ARGs and the potential risk of pathogens carrying ARGs. These findings provide a model simulation and theoretical basis for effectively reducing the threat of ARGs.

https://www.sciencedirect.com/science/article/abs/pii/S0269749122003906