摘要
      环境中的抗生素抗性基因( ARGs )及其随后被临床上重要的微生物获得是一个严重的问题。然而，环境 ARG的传播情况基本上无法得知。我们首次报道了土壤真菌通过土壤微环境参与细菌与精氨酸的分布。qPCR检测在不同真菌的真菌病圈中特异性发现的独特ARGs。有趣的是，分类和生态上不同的真菌对同一来源的ARGs产生不同的选择压力。测试真菌支持不同的抗生素抗性细菌，这些细菌富集在真菌病圈中，甚至转移到远处。粪便中tnpA基因的相对丰度沿着所有真菌的菌丝网络下降。相比两种来源的接种点，真菌菌株NFC - 5对int1基因的富集程度较高，与迁移前沿的两种其他真菌相反。这些数据表明不同真菌在真菌选择压力下促进水平基因转移潜力的差异效应。我们的研究提供了真菌能够促进ARGs、宿主细菌多样性和丰富性的证据，并且这种相互作用的微生物群落有可能将抗性决定因素从一个地方传播到另一个地方，从而增加ARGs暴露于人类的风险。

      Antibiotic resistance genes (ARGs) in the environment and their subsequent acquisition by clinically important microorganisms are a serious concern. However, the spread of environmental ARGs remain largely unknown. We report, for the first time, the involvement of soil fungi in the distribution of bacteria with ARGs via soil microcosms. qPCR assay detected unique ARGs specifically found in the mycosphere of different fungi. Interestingly, the taxonomically and ecologically different fungi exerted different selection pressures on ARGs originating from the same source. Test fungi supported different antibiotic resistance bacteria enriched in the mycosphere and even transported to distant places. The relative abundance of the tnpA gene decreased, for manure, along mycelial networks of all fungi. While the fungal strain NFC-5 enriched the intI1 gene more, opposite to two other fungi at the migration front compared with the inoculation point for both sources. Such data indicate the differential effect of different fungi to facilitate horizontal gene transfer potential under fungal selection pressure. Our study provides the evidence that fungi can contribute ARGs, host bacterial diversity and abundance, and such interactive microbial consortia have the potential to disseminate the resistance determinants from one place to another, thus increasing the ARGs exposure risk to humans.

https://www.nature.com/articles/s41598-017-15660-7