State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing, 100049, China.
Key Laboratory of Urban Environment and Health, Ningbo Urban Environment Observation and Research Station, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, China; Zhejiang Key Laboratory of Urban Environmental Processes and Pollution Control, CAS Haixi Industrial Technology Innovation Center in Beilun, Ningbo, 315830, China.
Environ Pollut. 2023 Jun 1;326:121486. doi: 10.1016/j.envpol.2023.121486. Epub 2023 Mar 22.
Owing to convenient water access, riparian areas are often sites for intensive livestock breeding industries and agriculture, which can increase the spread of antibiotic resistance genes (ARGs). However, studies on ARG profiles in riparian soils are limited and there is little information regarding the factors influencing ARGs at a watershed scale. Here, we analyzed ARG profiles, bacterial communities, and soil properties in riparian soils under different land-use types. A total of 124 ARGs and 25 mobile genetic elements (MGEs) were detected in the riparian soils, which covered almost all major classes of antibiotics. Non-metric multidimensional scaling analysis showed that both the distance to the water reservoir and land-use types played important roles in shaping ARG profiles in riparian soils at a watershed scale. Downstream soils harbored three times the abundance of ARGs compared with upstream and midstream soils. Distance-decay analysis indicated that the similarity of ARG profiles and bacterial community composition decreased significantly with the increase of geographical distance (p < 0.001). When taking the land-use type into consideration, the relative abundance and diversity of ARGs and MGEs in orchard and farmland soils were significantly higher than those in wasteland soils. This indicated that anthropogenic activities can also affect ARG patterns in riparian soils. MGE abundance was identified as major driving factors of ARG profiles. In addition, among all the examined soil properties, soil pH was found to be more important than nutrients and organic carbon in shaping ARG profiles. Our findings provide valuable data on ARG distribution in riparian soils in a reservoir catchment and highlight downstream soils is crucial for ensuring water source security.
由于滨水地区便于获取水源，因此常被用于集约化的畜牧业和农业生产，这可能会增加抗生素耐药基因（ARGs）的传播。然而，有关滨岸土壤中 ARG 谱的研究有限，且关于流域尺度上影响 ARGs 的因素的信息很少。在此，我们分析了不同土地利用类型下滨岸土壤中的 ARG 谱、细菌群落和土壤特性。在滨岸土壤中检测到了 124 种 ARG 和 25 种移动遗传元件（MGE），涵盖了几乎所有主要类别的抗生素。非度量多维尺度分析表明，距水库的距离和土地利用类型都对流域尺度上滨岸土壤中 ARG 谱的形成起着重要作用。与上游和中游土壤相比，下游土壤中的 ARG 丰度高出三倍。距离衰减分析表明，ARG 谱和细菌群落组成的相似性随着地理距离的增加而显著降低（p<0.001）。考虑到土地利用类型，果园和农田土壤中 ARG 和 MGE 的相对丰度和多样性明显高于荒地土壤。这表明人为活动也会影响滨岸土壤中的 ARG 模式。MGE 丰度是 ARG 谱的主要驱动因素。此外，在所检查的所有土壤特性中，土壤 pH 值对 ARG 谱的形成比养分和有机碳更为重要。我们的研究结果为水库流域滨岸土壤中 ARG 分布提供了有价值的数据，并强调了下游土壤对于确保水源安全至关重要。
