摘要
      抗生素抗性基因在水产养殖系统中的传播对环境安全和人类健康构成潜在威胁。然而，ARGs的时空分布模式及其在水产养殖沉积物中传播的关键因素尚不清楚。在本研究中，对从一个有代表性的水产养殖场的整个鱼类养殖周期中采集的样本的ARGs、可移动遗传元素、微生物群落组成、重金属含量和营养成分进行了表征。9种ARGs亚型（tetW、tetM、tetA、ermC、ermB、sul1、sul2、floR和qnrS）的分布模式显示出明显的时空差异。养殖沉积物中ARGs的绝对丰度在冬季和养殖场的河流中较高。变形杆菌门是所有沉积物样品中的优势门。网络和冗余分析的结果证实，变形杆菌属的脱氯单胞菌、Candidatus Accumulibacter、Smithlla、Geobacter和Anaeromycobacter与ARGs呈正相关，表明这些微生物物种是相应ARGs的潜在宿主。我们的研究强调，微生物群落是ARG传播的决定因素。抑制ARGs这些潜在宿主的策略应基于可控因素制定。
Abstract
The dissemination of antibiotic resistance genes (ARGs) in aquaculture systems is a potential threat to environmental safety and human health. However, the spatiotemporal distribution pattern of ARGs and key factors associated with their dissemination in aquaculture sediments remain unclear. In this study, ARGs, mobile genetic elements, microbial community composition, heavy metal contents, and nutrient contents of samples collected from a whole culture cycle of fish in a representative aquaculture farm were characterized. The distribution patterns of nine subtypes of ARGs (tetW, tetM, tetA, ermC, ermB, sul1, sul2, floR, and qnrS) showed clear spatiotemporal differences. The absolute abundance of ARGs in aquaculture sediments was higher in winter and in rivers of the aquaculture farm. Proteobacteria was the dominant phylum in all sediment samples. The results of network and redundancy analyses confirmed that the Dechloromonas, Candidatus Accumulibacter, Smithella, Geobacter, and Anaeromyxobacter belonging to Proteobacteria were positively correlated with ARGs, suggesting that these microbial species are potential hosts of corresponding ARGs. Our study highlights that the microbial community is the determining factor for ARG dissemination. Strategies for inhibiting these potential hosts of ARGs should be developed based on controllable factors.

https://www.sciencedirect.com/science/article/abs/pii/S0045653522020896