Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
J Environ Sci (China). 2022 May;115:363-373. doi: 10.1016/j.jes.2021.08.006. Epub 2021 Aug 24.
The global dissemination of antibiotic resistance genes (ARGs), especially via plasmid-mediated horizontal transfer, is becoming a pervasive health threat. While our previous study found that herbicides can accelerate the horizontal gene transfer (HGT) of ARGs in soil bacteria, the underlying mechanisms by which herbicides promote the HGT of ARGs across and within bacterial genera are still unclear. Here, the underlying mechanism associated with herbicide-promoted HGT was analyzed by detecting intracellular reactive oxygen species (ROS) production, extracellular polymeric substance composition, cell membrane integrity and proton motive force combined with genome-wide RNA sequencing. Exposure to herbicides induced a series of the above bacterial responses to promote HGT except for the ROS response, including compact cell-to-cell contact by enhancing pilus-encoded gene expression and decreasing cell surface charge, increasing cell membrane permeability, and enhancing the proton motive force, providing additional power for DNA uptake. This study provides a mechanistic understanding of the risk of bacterial resistance spread promoted by herbicides, which elucidates a new perspective on nonantibiotic agrochemical acceleration of the HGT of ARGs.
抗生素耐药基因（ARGs）在全球范围内的传播，特别是通过质粒介导的水平转移，正成为一种普遍的健康威胁。虽然我们之前的研究发现，除草剂可以加速土壤细菌中 ARGs 的水平基因转移（HGT），但除草剂促进 ARGs 在细菌属间和属内转移的潜在机制仍不清楚。本研究通过检测细胞内活性氧（ROS）的产生、细胞外聚合物成分、细胞膜完整性和质子动力势，并结合全基因组 RNA 测序，分析了与除草剂促进 HGT 相关的潜在机制。暴露于除草剂会诱导一系列上述细菌反应来促进 HGT，除了 ROS 反应外，还包括通过增强菌毛编码基因的表达和降低细胞表面电荷来增强细胞间的紧密接触，增加细胞膜通透性，并增强质子动力势，为 DNA 摄取提供额外的动力。这项研究提供了对抗生素耐药性传播风险的机制理解，阐明了农用化学品非抗生素加速 ARGs 的 HGT 的新视角。
