摘要
      全球病原微生物抗生素耐药性水平的上升对人类健康构成了重大威胁。新鲜蔬菜已被认为是从环境到人类的抗生素抗性基因（ARGs）的重要载体。叶际ARGs已被表明会随着植物种类的变化而变化，但植物品种对叶际抗性的影响尚不清楚。在这里，我们分别使用高通量定量PCR技术和基于细菌16S rRNA基因的高通量测序检测了两个香菜品种及其相应土壤的叶层中的ARGs和细菌群落。我们进一步鉴定了潜在的细菌病原体，并分析了植物品种对ARGs、移动遗传元件（MGE）、微生物组和潜在细菌病原体的影响。结果表明，品种对ARG的丰度和组成没有影响，但显著影响了MGE的丰度和叶层细菌的组成结构。潜在细菌病原体在叶层中的相对丰度显著高于在土壤中的相对丰富度。Mantel检验表明，ARG模式与潜在细菌病原体的模式显著相关。我们的研究结果表明，两个香菜品种在叶层中ARGs的水平基因转移可能不同，并强调了与土壤中相比，叶层微生物的风险更高。这些发现扩展了我们对蔬菜微生物群、ARGs和潜在病原体的了解，表明需要更多的农业和卫生协议来控制食源性ARGs的风险。
Abstract
The global increased antibiotic resistance level in pathogenic microbes has posed a significant threat to human health. Fresh vegetables have been recognized to be an important vehicle of antibiotic resistance genes (ARGs) from environments to human beings. Phyllosphere ARGs have been indicated to be changed with plant species, yet the influence of plant cultivar on the phyllospheric resistome is still unclear. Here, we detected the ARGs and bacterial communities in the phyllosphere of two cultivars of cilantros and their corresponding soils using high-throughput quantitative PCR technique and bacterial 16S rRNA gene-based high-throughput sequencing, respectively. We further identified the potential bacterial pathogens and analyzed the effects of plant cultivar on ARGs, mobile genetic elements (MGEs), microbiome and potential bacterial pathogens. The results showed that the cultivars did not affect the ARG abundance and composition, but significantly shaped the abundance of MGEs and the composition structure of bacteria in the phyllosphere. The relative abundance of potential bacterial pathogens was significantly higher in the phyllosphere than that in soils. Mantel test showed that the ARG patterns were significantly correlated to the patterns of potential bacterial pathogens. Our results suggested that the horizontal gene transfer of ARGs in the phyllosphere might be different between the two cultivars of cilantro and highlighted the higher risk of phyllospheric microorganisms compared with those in soils. These findings extend our knowledge on the vegetable microbiomes, ARGs, and potential pathogens, suggesting more agricultural and hygiene protocols are needed to control the risk of foodborne ARGs.

https://www.sciencedirect.com/science/article/abs/pii/S1001074222003187