摘要
      受人为活动动态干扰的城市河流被认为是抗生素耐药性基因（ARGs）的重要库。在此，对北京潮白河的水和沉积物中总 共198个ARGs和12个可移动遗传元素（MGE）进行了分析。ARGs的总丰度（水中1.01×106–4.58×108拷贝/L，沉积物2.92×106–3.34×109拷贝/g）以β-内酰胺酶基因为主，表现出显著的季节变化（p<0.05）。在水和沉积物中观察到ARGs和MGEs的总丰度之间存在显著的线性相关性（p<0.01）。方差划分分析表明，环境变量（即水温（WT）、溶解氧（DO）、营养素、金属，等）和抗生素是ARGs和MGE变异的主要原因，分别解释了ARGs总变异的55-80%和27-67%。偏最小二乘路径模型表明，水和沉积物中ARG的丰度直接和间接受到环境变量和抗生素的影响，但直接受到MGE的影响。此外，随机森林算法发现，WT、Ni、DO、Co、聚醚类和大环内酯类抗生素是ARGs在水中传播的主要驱动因素（>10%），而Tp614、tnpA和IS613的转座酶基因是ARG在水和沉积物中传播的主要驱动因素。本研究全面了解了ARGs在城市河流中传播的驱动因素，对抗生素耐药性的风险管理具有重要意义。
Abstract
Urban rivers dynamically interfered by anthropogenic activities are considered as a vital reservoir of antibiotic resistance genes (ARGs). Here, a total of 198 ARGs and 12 mobile genetic elements (MGEs) were profiled in water and sediment from the Chaobai river, Beijing. The total abundances of ARGs (1.01 × 106–4.58 × 108 copies/L in water and 2.92 × 106–3.34 × 109 copies/g in sediment), which were dominated by beta-lactamase genes, exhibited significant seasonal variations (p < 0.05). Significant linear correlations between the total abundances of ARGs and MGEs were observed in both water and sediment (p < 0.01). Variance partitioning analysis disclosed that environmental variables (i.e., water temperature (WT), dissolved oxygen (DO), nutrients, metals, etc.) and antibiotics were the main contributors to the variations of ARGs and MGEs, and explained 55–80 % and 27–67 % of the total variations in ARGs and MGEs, respectively. The partial least-squares path model revealed the ARG abundances in water and sediment were affected by environmental variables and antibiotics both directly and indirectly but by MGEs directly. Moreover, random forest algorithm explored that WT, Ni, DO, Co, and polyether and macrolide antibiotics were the main drivers (>10 %) of ARGs dissemination in water, whereas the transposase genes of Tp614, tnpA, and IS613 were the main drivers of ARGs dissemination in both water and sediment. This study provides a comprehensive understanding of the driving factors for the ARGs dissemination in an urban river, which is of great significance for risk management of antibiotic resistome.

https://www.sciencedirect.com/science/article/abs/pii/S0048969722036336