摘要
农业土壤通过食物供应与人类健康密切相关，已被公认为抗生素抗性基因（ARGs）的重要库。然而，关于土壤团聚体在形成ARG剖面中的作用，仍然缺乏相关知识。在这项研究中，我们从长期试验农田中收集了接受无机和/或有机肥料的土壤，并使用高通量定量聚合酶链式反应（HT-qPCR）检测了不同大小土壤团聚体中抗生素耐药性的分布模式。我们的研究结果表明，土壤ARGs的分布可能单独受到粪肥施用和团聚体粒径的影响，但不会相互影响。与非施肥土壤相比，在施肥土壤中发现了更多样化和丰富的ARG。小于53μm的骨料粒级表现出最高的ARGs多样性和丰度。变异划分分析表明，土壤性状、可移动遗传元素和细菌群落共同促成了土壤抗生素耐药性的变异。本研究中获得的关于土壤ARGs聚集分层的知识对于在微观尺度上理解土壤ARG的命运是至关重要的。
Abstract
Agricultural soils, which are closely linked to human health via food supply, have been recognized as an important reservoir for antibiotic resistance genes (ARGs). However, there is still a lack of knowledge regarding the role of soil aggregates in shaping ARG profile. In this study, we collected soils from long-term experimental farmland plots receiving inorganic and/or organic fertilizers and examined the patterns of antibiotic resistome distribution among differently sized soil aggregates using high-throughput quantitative polymerase chain reaction (HT-qPCR). Our results showed that the distribution of soil ARGs could be affected by manure application and aggregate size individually but not interactively. More diverse and abundant ARGs were found in the manured soils, compared to the non-manured soils. The aggregate size fraction of <53 μm exhibited the highest diversity and abundance of ARGs. Variation partitioning analysis revealed that soil traits, mobile genetic elements, and bacterial community collectively contributed to the variation of soil antibiotic resistance. The knowledge about aggregation stratification of soil ARGs obtained in this study is fundamental and essential to understanding the fate of soil ARGs at the microscale.

https://www.sciencedirect.com/science/article/abs/pii/S0048969722021817