摘要

    这项研究旨在破译在相互联系的湖泊-河流-水库系统中的抗生素抗性基因（ARG）的模式以及关键非生物指标与ARG的联系。结果表明，ARGs和流动基因元件（MGEs）相对丰度的季节变化显着（KW，p <0.05）。代表粪便污染和自然环境的ARGs主要分布在河流和水库中。湖泊，河流和水库共有54.5％的ARGs亚型，其中大多数是编码外排泵的多药耐药基因。网络结果表明，赋予对氨基糖苷耐药性的ARG与1类整合素和Limnohabitans经常同时出现。耐药风险较低且与非相应的ARGs有关，耐药风险最高的是滇山湖中的恩诺沙星。从两种方法得出的荧光指数与单个基因（即aada1和aadA2-03）以及总的氨基糖苷抗性基因（Pearson，p <0.05）的丰度具有一致的正相关性。此外，人类和动物粪便污染的ARGs指标显示出与腐殖质样和腐殖质样指数相关（Pearson，p <0.05）。结果为非生物因素在指示人为活动影响的水生环境中ARGs动态中的作用提供了新颖的见解。

   This study aimed to decipher the patterns of antibiotic resistance genes (ARGs) and linkages of key abiotic indicators with ARGs in an interconnected lake-river-reservoir system. The results showed that seasonal variations in the relative abundance of ARGs and mobile gene elements (MGEs) were significant (KW, p < 0.05). ARGs representative of fecal pollution and natural environment were primarily distributed in the river and reservoir, respectively. The lake, river, and reservoir shared 54.5% of ARGs subtypes, most of which are multidrug resistance genes encoding for efflux pumps. Network results showed that ARGs conferring resistance to aminoglycoside frequently co-occurred with class 1 integrons and Limnohabitans. The resistance risks were low and associated with non-corresponding ARGs, and the highest resistance risk was caused by enrofloxacin in the Dianshan Lake. Fluorescence indices derived from two methods exhibited consistent positive correlations with abundance of individual genes (i.e. aada1 and aadA2-03) as well as total aminoglycoside resistance genes (Pearson, p < 0.05). Moreover, ARGs indicators of human and animal fecal pollution showed linkages with humic-like and fulvic-like indices (Pearson, p < 0.05). The results provide novel insights into the roles of abiotic factors on indicating dynamics of ARGs in aquatic environment impacted by anthropogenic activities.

    https://www.sciencedirect.com/science/article/abs/pii/S0304389420325425