摘要

      抗药性基因（ARGs）在水生环境中广泛存在，但对其在全国范围内的生物地理分布和发生情况知之甚少。本文采用高通量方法分析了中国42个天然水体（天然湖泊和水库）中的ARG形态。主要的ARGs是多药基因，耐药机制主要是外排泵。尽管南部/中部水体ARGs的绝对丰度（基因拷贝数/L）与北部水体相似，但南部/中部水体ARGs的标准丰度（ARGs/16srrna基因拷贝数）高于北部（主要是由于氨基糖苷和多药耐药基因）。人类活动与ARGs的正常化丰度密切相关。华南/华中地区水体中ARGs的组成与北方不同，且呈距离衰减关系。人为因素对ARG的空间分布影响最大，其次是空间因素、细菌因素和理化因素。这些结果表明，ARGs具有生物地理格局，环境选择（人类活动和局部物理化学参数）和扩散限制等多种生态机制影响着ARGs在这些水域的分布。总的来说，我们的结果提供了一个有价值的生态学见解来解释ARGs中的大规模扩散模式，从而在公共卫生和环境管理方面都有潜在的应用。

       Antibiotic resistance genes (ARGs) are widespread in aquatic environments, but we know little about their biogeographical distribution and occurrence at national scales. Here we analyzed the patterns of ARGs from 42 natural waterbodies (natural lakes and reservoirs) across China using high-throughput approaches. The major ARGs were multidrug genes and the main resistance mechanism was the efflux pump. Although the absolute abundance of ARGs (gene copies/L) in the south/central waterbodies was similar to the northern waterbodies, the normalized abundance of ARGs (ARGs/16S rRNA gene copy number) was higher in the south/central waterbodies than in the north (mainly because of the aminoglycoside and multidrug resistance genes). Human activities strongly correlated with the normalized abundance of ARGs. The composition of ARGs in the waterbodies of south/central China was different from that in the north, and ARGs showed a distance-decay relationship. Anthropogenic factors had the most significant effects on this spatial distribution of ARG composition, followed by the spatial, bacterial and physicochemical factors. These indicate that the ARGs exhibited biogeographical patterns and that multiple ecological mechanisms - such as environmental selection (human activities and local physicochemical parameters) and dispersal limitation - influence distribution of ARGs in these waters. In general, our results provide a valuable ecological insight to explain the large-scale dispersal patterns in ARGs, thereby having potential applications for both public health and environmental management.

        https://www.sciencedirect.com/science/article/pii/S0160412017319906?via%3Dihub