College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China.
Institute of Environmental Processes and Pollution Control, and School of Environment and Civil Engineering, Jiangnan University, Wuxi 214122, China.
Environ Sci Technol. 2020 Aug 18;54(16):10012-10021. doi: 10.1021/acs.est.0c01870. Epub 2020 Jul 29.
The dissemination and propagation of antibiotic resistance genes (ARGs) via plasmid-mediated conjugation pose a major threat to global public health. The potential effects of nanomaterials on ARGs fates have drawn much attention recently. In this study, CeO nanoparticles (NPs), one of the typical nanomaterials proposed for increasing crop production, were applied at the concentration range of 1-50 mg/L to investigate their effects on ARGs transfer between . Our results revealed that the conjugative transfer of RP4 plasmid was enhanced by 118-123% at relatively high concentrations (25 and 50 mg/L) of CeO NPs, however, CeO NPs at low concentrations (1 and 5 mg/L) inhibited the transfer by 22-26%. The opposite effect at low concentrations is mainly attributed to (i) the reduced ROS level, (ii) the weakened intercellular contact via inhibiting the synthesis of polysaccharides in extracellular polymeric substances, and (iii) the down-regulated expression of plasmid transfer genes due to the shortage of ATP supply. Our findings highlight the distinct dose-dependent responses of ARGs conjugative transfer, providing evidence for selecting appropriate NPs dose to reduce the spread of ARGs while applying nanoagrotechnology.
质粒介导的接合导致抗生素耐药基因（ARGs）的传播和扩散，对全球公共健康构成了重大威胁。最近，纳米材料对 ARGs 命运的潜在影响引起了广泛关注。在这项研究中，我们采用浓度范围为 1-50mg/L 的 CeO 纳米颗粒（NPs）作为一种典型的纳米材料，用于提高作物产量，研究其对. 之间 ARGs 转移的影响。结果表明，CeO NPs 在较高浓度（25 和 50mg/L）下增强了 RP4 质粒的接合转移，增强幅度为 118-123%，而在较低浓度（1 和 5mg/L）下则抑制了转移，抑制幅度为 22-26%。低浓度下的相反效果主要归因于：（i）ROS 水平降低，（ii）通过抑制细胞外聚合物中多糖的合成，减弱细胞间接触，以及（iii）由于 ATP 供应不足，质粒转移基因的表达下调。我们的研究结果突出了 ARGs 接合转移的明显剂量依赖性反应，为在应用纳米农业技术时选择适当的 NPs 剂量以减少 ARGs 的传播提供了证据。
