摘要

       随着世界范围内大坝的快速建设，水库系统已成为现代水环境的代表。然而，抗生素耐药基因（ARGs）的分布及其在现代水环境（如水相、沉积物相和土壤相）中影响其动态的相关因素在很大程度上是未知的。在此，我们采用高通量定量PCR技术对大型饮用水水库中精氨酸的多样性、丰度、分布进行了综合表征，并对影响因素进行了排序（如：移动遗传因素、细菌群落、细菌生物量、抗生素等），基于结构方程模型（SEMs）对ARGs剖面的影响。相较于沉积相和土壤相，水相更容易形成多样性的ARGs，而降落区的土壤相是ARGs的潜在储集层和研究热点。环境介质在一定程度上影响了现代水环境中ARG的多样性，同时也显著影响了ARGs和MGEs的分布及其共生模式。ARGs在水体中的增殖和扩散途径为水平基因转移（HGT）和垂直基因转移（VGT），而在沉积物和土壤中的优势途径分别为HGT和VGT。SEMs分析表明，MGEs对水体和沉积物中ARG动态的驱动作用最大，而细菌群落对土壤中ARG动态的驱动作用最大。总的来说，环境介质对现代水环境中ARGs的动力学起到了瓶颈作用，可能是由于mge、细菌群落、细菌生物量、抗生素和基本性质的多样化。

       With the rapid construction of dams worldwide, reservoir system has become a representation of modern aquatic environment. However, the profiles of antibiotic resistance genes (ARGs) and associated factor influencing their dynamics in modern aquatic environment (e.g., water phase, sediment phase, and soil phase) are largely unknown. Here, we comprehensively characterized the diversity, abundance, distribution of ARGs in a large drinking water reservoir using high-throughput quantitative PCR, as well as ranked the factors (e.g., mobile genetic elements (MGEs), bacteria community, bacterial biomass, antibiotics, and basic properties) influencing the profiles of ARGs on the basis of structural equation models (SEMs). Water phase was prone to harbor more diverse ARGs as compared to sediment phase and soil phase, and soil phase in drawdown area was a potential reservoir and hotspot for ARGs. Environmental media partially affected the ARG diversity in modern aquatic environment, while it observably influenced the distributions of ARGs and MGEs and their co-occurrence patterns. The pathways for the proliferation and spread of ARGs in water phase were both the horizontal gene transfer (HGT) and vertical gene transfer (VGT), while the dominant pathways in sediment phase and soil phase were the HGT and VGT, respectively. The SEMs demonstrated that MGEs contributed the most to drive the ARG dynamics in both water phase and sediment phase, while the most dominant factor for this in soil phase was bacterial community. Overall, environmental media exerted a bottleneck in driving the dynamics of ARGs in modern aquatic environment probably via diversifying the MGEs, bacterial community, bacterial biomass, antibiotics and basic properties.

        https://www.sciencedirect.com/science/article/abs/pii/S0043135419305603?via%3Dihub