摘要
      草地占全球农业用地的很大一部分，用于喂养食草动物和反刍动物，并通过动物和人类将环境与食物链联系起来。然而，大多数关于环境-动物关系中抗微生物耐药性和微生物组的科学研究都集中在土壤或蔬菜上，而不是草地上。基于之前的微生物组叶际土壤研究，我们假设土壤和草地上的微生物组和抗性体将具有共享分类群和抗微生物抗性基因（ARGs）的核心，但除此之外，每种微生物组和耐药性基因也将具有少数独特的特征。我们的数据表明，与添加或不添加浆料改良剂的土壤相比，草含有更广泛的ARGs和可移动遗传元素（MGE），相对丰度更高。土壤和草地的微生物组含量相似，但组成比例不同。虽然土壤和草地上存在的许多ARG具有共性，但它们与MGE和细菌的相关性不同，这表明土壤以外的来源也与草地的抗性有关。土壤和草地上ARGs相对丰度的变化也表明，MGE或携带ARGs的细菌在草地上的相对丰度高于土壤。我们得出的结论是，虽然土壤可能是其中一些基因的来源，但它不可能是所有ARGs和MGE的来源。我们的数据表明，与土壤相比，草地是环境中ARGs和MGE更多样、更丰富的宿主，从放牧食物动物的角度来看，这对人类和动物的健康具有重要意义。
Abstract
Grasslands cover a large proportion of global agricultural landmass used to feed herbivores and ruminants and link the environment to the food chain via animals onto humans. However, most scientific studies of antimicrobial resistance and microbiomes at the environmental – animal nexus have focused on soil or vegetables rather than grasslands. Based on previous microbiome phyllosphere-soil studies we hypothesised that the microbiome and resistomes across soil and grass would have a core of shared taxa and antimicrobial resistance genes (ARGs), but that in addition each would also have a minority of unique signatures. Our data indicated grass contained a wider variety and higher relative abundance of ARGs and mobile genetic elements (MGEs) than soil with or without slurry amendments. The microbiomes of soil and grass were similar in content but varied in the composition proportionality. While there were commonalities across many of the ARGs present in soil and on grass their correlations with MGEs and bacteria differed, suggesting a source other than soil is also relevant for the resistome of grass. The variations in the relative abundances of ARGs in soil and on grass also indicated that either the MGEs or the bacteria carrying the ARGs comprised a higher relative abundance on grass than in soil. We conclude that while soil may be a source of some of these genes it cannot be the source for all ARGs and MGEs. Our data identifies grass as a more diverse and abundant reservoir of ARGs and MGEs in the environment than soil, which is significant to human and animal health when viewed in the context of grazing food animals.

https://www.sciencedirect.com/science/article/pii/S0048969722062787