摘要

       动物粪便的土地施用作为一种重要的农艺实践，代表了将抗生素抗性基因 (ARG) 传播到土壤环境中的潜在途径。先前的研究表明，粪肥衍生的 ARGs 和病原生物在施用粪肥后随时间迅速减少，然而，长期和重复施用动物粪肥对土壤 ARGs 的多样性和丰度的影响仍然知之甚少。在这里，我们研究了长期施用奶牛和鸡粪（DM 和 CM）的温室土壤中 ARG 的多样性和丰度，以及从中国太原的粪肥土壤中分离出的抗生素抗性细菌 (ARB) 的半衰期。 DM和CM均显着提高了残留抗生素水平、ARGs、intI1的丰度以及土壤有机碳和总氮，两者之间存在密切联系。 ARB的半衰期不同，从ARB中提取的ARGs、intI1和tnpA遗传元件与培养时间的相关性不同。耐药菌数量与半衰期之间存在显着正相关。我们的发现表明，抗生素的水平和 ARGs 的稳定性将决定施肥土壤中 ARGs 的多样性和丰度。

       Land application of animal manure, as an important agronomic practice, represents a potential route to disseminate antibiotic resistance genes (ARGs) into the soil environment. Previous studies have demonstrated that manure-derived ARGs and pathogenic organisms rapidly decline over time following manure application, however, the impacts of long-term and repeated application of animal manure on the diversity and abundance of soil ARGs remain less understood. Here, we investigated the diversity and abundance of ARGs in greenhouse soils with long-term dairy cattle and chicken manure (DM and CM) application, and the half-life of antibiotic resistant bacteria (ARB) isolated from manured soils in Taiyuan, China. Both DM and CM significantly improved the levels of residual antibiotics, the abundances of ARGs, intI1 and soil organic carbon and total nitrogen that there was strong link between them. The half-life of ARB was different, and the correlations of ARGs, intI1 and tnpA genetic elements extracted from ARB with culture times were different. The significantly positive link was between the population of resistance bacteria and the half-life. Our finding suggested that both the levels of antibiotics and the stability of ARGs will determine the diversity and abundance of ARGs in manured soils.

https://www.sciencedirect.com/science/article/abs/pii/S0929139317308685