摘要

虽然已经确定农业土壤和产品中存在抗生素抗性基因（ARGs），但它们在不同植物部分之间的分布以及农业实践的贡献，包括用再生水灌溉，尚未得到充分解决。为此，我们分析了来自两个土壤，根，叶和果实的七种ARG（sul1，blaTEM，blaCTX-M-32，mecA，qnrS1，tetM，blaOXA-58）和整合酶基因intl1的水平。使用不依赖于培养的定量实时PCR方法，用未受污染的地下水或受处理废水影响的通道灌溉商业番茄田。在叶和果实中发现ARG和intl1序列的水平占根或土壤中发现的1至10％。 intl1序列的相对丰度与tetM，blaTEM和sul1水平相关，表明这些ARG具有高水平迁移潜力。高通量16S rDNA测序揭示了样品类型（土壤加根与叶加水果）和采样区之间的微生物组差异，以及假单胞菌的流行与不同ARG水平之间的相关性，特别是在果实和叶片中。我们得出结论，植物部分（包括果实）中的微生物组成和ARG水平可能都受到农业实践的影响。

While the presence of antibiotic resistance genes (ARGs) in agricultural soils and products has been firmly established, their distribution among the different plant parts and the contribution of agricultural practices, including irrigation with reclaimed water, have not been adequately addressed yet. To this end, we analyzed the levels of seven ARGs (sul1, blaTEM, blaCTX-M-32, mecA, qnrS1, tetM, blaOXA-58), plus the integrase gene intl1, in soils, roots, leaves, and fruits from two commercial tomato fields irrigated with either unpolluted groundwater or from a channel impacted by treated wastewater, using culture-independent, quantitative real-time PCR methods. ARGs and intl1 sequences were found in leaves and fruits at levels representing from 1 to 10% of those found in roots or soil. The relative abundance of intl1 sequences correlated with tetM, blaTEM, and sul1 levels, suggesting a high horizontal mobility potential for these ARGs. High-throughput 16S rDNA sequencing revealed microbiome differences both between sample types (soil plus roots versus leaves plus fruits) and sampling zones, and a correlation between the prevalence of Pseudomonadaceae and the levels of different ARGs, particularly in fruits and leaves. We concluded that both microbiome composition and ARGs levels in plants parts, including fruits, were likely influenced by agricultural practices.

https://www.sciencedirect.com/science/article/pii/S0048969718341640