摘要

       肥料改良土壤中抗药性的增加可能进入食物链，是抗药性基因（ARGs）进入人体微生物群的重要载体。然而，ARGs从土壤到植物的传播途径仍然不清楚。本文研究了畜禽粪和牛粪对土壤和莴苣根际、根际、叶际和叶际等微生物的抗性模式的影响，以确定ARGs在土壤-植物系统中的潜在传播途径。培养90 天后，用高通量定量PCR方法检测了所有样品中144个精氨酸。与莴苣的其他成分相比，根际土壤中含有最多的ARGs。施用牛粪增加了根内生菌中ARGs的含量，而施用鸡粪增加了根际、根内生菌和叶面层中ARGs的含量，说明施用鸡粪对莴苣抗性有较强的影响。ARG谱与细菌群落呈显著相关，土壤和植物抗性的富集受细菌类群的强烈影响，如网络分析所示，细菌类群包括溶杆菌、绿曲菌、酸杆菌、Gemm-1和金霉素单胞菌。此外，还发现了莴苣组织与土壤中ARGs的重叠，表明植物和环境抗性是相互联系的。我们的发现揭示了ARGs从肥沃土壤到蔬菜的传播途径，并强调了植物抵抗迁移到人类食物链的潜在风险。

       The increasing antimicrobial resistance in manure-amended soil can potentially enter food chain, representing an important vehicle for antibiotic resistance genes (ARGs) transmission into human microbiome. However, the pathways for transmission of ARGs from soil to plant remain unclear. Here, we explored the impacts of poultry and cattle manure application on the patterns of resistome in soil and lettuce microbiome including rhizosphere, root endosphere, leaf endosphere and phyllosphere, to identify the potential transmission routes of ARGs in the soil-plant system. After 90 days of cultivation, a total of 144 ARGs were detected in all samples using high-throughput quantitative PCR. Rhizosphere soil samples harbored the most diverse ARGs compared with other components of lettuce. Cattle manure application increased the abundance of ARGs in root endophyte, while poultry manure application increased ARGs in rhizosphere, root endophyte and phyllosphere, suggesting that poultry manure may have a stronger impact on lettuce resistomes. The ARG profiles were significantly correlated with the bacterial community, and the enrichment of soil and plant resistomes was strongly affected by the bacterial taxa including Solibacteres, Chloroflexi, Acidobacteria, Gemm-1 and Gemmatimonadetes, as revealed by the network analyses. Moreover, the overlaps of ARGs between lettuce tissues and soil were identified, which indicated that plant and environmental resistomes are interconnected. Our findings provide insights into the transmission routes of ARGs from manured soil to vegetables, and highlight the potential risks of plant resistome migration to the human food chain.

       https://www.sciencedirect.com/science/article/pii/S0160412019312735?via%3Dihub