摘要

      尽管全世界普遍关注抗生素耐药热点，但对不同潜在来源对全球风险的贡献却知之甚少。本文对分布在巴塞罗那（西班牙东北部）附近四个地理区的9个商业区种植的番茄、莴苣和蚕豆作物（共165个样品）的土壤、根际土壤、根、叶和豆类中抗生素抗性基因（ARGs）的分布进行了定量分析。我们还分析了附近森林的五个土壤样本，没有农业活动的记录。用qPCR方法分析DNA样本中ARGs sul1、tetM、qnrS1、blaCTX-M-32、blaOXA-58、mecA和blaTEM以及integron intI1的含量。此外，通过扩增子靶向16s rRNA基因测序对不同样地的土壤微生物进行了分析。我们的数据显示，从土壤到水果和豆类的ARG负荷梯度下降，后者仅显示土壤丰度值的0.1%到0.01%。作物类型是决定不同地块间ARG分布和微生物组分的主要因素，地理位置和灌溉水源的贡献较小。我们认为，土壤改良和/或施肥比灌溉水更能驱动作物可食用部分的ARG负荷，因此应特别加以控制。

       Despite the social concern about the generalization of antibiotic resistance hotspots worldwide, very little is known about the contribution of different potential sources to the global risk. Here we present a quantitative analysis of the distribution of Antibiotic Resistance Genes (ARGs) in soil, rhizospheric soil, roots, leaves and beans in tomato, lettuce and broad beans crops (165 samples in total), grown in nine commercial plots distributed in four geographical zones in the vicinity of Barcelona (North East Spain). We also analyzed five soil samples from a nearby forest, with no record of agricultural activities. DNA samples were analyzed for their content in the ARGs sul1, tetM, qnrS1, bla_CTX-M-32, bla_OXA-58, mecA, and bla_TEM, plus the integron intI1, using qPCR methods. In addition, soil microbiomes from the different plots were analyzed by amplicon-targeted 16S rRNA gene sequencing. Our data show a decreasing gradient of ARG loads from soil to fruits and beans, the latter showing only from 0.1 to 0.01% of the abundance values in soil. The type of crop was the main determinant for both ARG distribution and microbiome composition among the different plots, with minor contributions of geographic location and irrigation water source. We propose that soil amendment and/or fertilization, more than irrigation water, are the main drivers of ARG loads on the edible parts of the crop, and that they should therefore be specifically controlled.

       https://www.sciencedirect.com/science/article/abs/pii/S0013935119304050?via%3Dihub