Xu Yinuo, Du Hao, Wang Chuanxi, Yue Le, Chen Feiran, Wang Zhenyu
Institute of Environmental Processes and Pollution Control, and School of Environmental and Civil Engineering, Jiangnan University, Wuxi 214122, China.
Jiangsu Engineering Laboratory for Biomass Energy and Carbon Reduction Technology, Jiangnan University, Wuxi 214122, China.
Nanomaterials (Basel). 2023 Mar 8;13(6):969. doi: 10.3390/nano13060969.
The direct uptake of extracellular DNA (eDNA) via transformation facilitates the dissemination of antibiotic resistance genes (ARGs) in the environment. CeO nanoparticles (NPs) have potential in the regulation of conjugation-dominated ARGs propagation, whereas their effects on ARGs transformation remain largely unknown. Here, CeO NPs at concentrations lower than 50 mg L have been applied to regulate the transformation of plasmid-borne ARGs to competent () cells. Three types of exposure systems were established to optimize the regulation efficiency. Pre-incubation of competent cells with CeO NPs at 0.5 mg L inhibited the transformation (35.4%) by reducing the ROS content (0.9-fold) and cell membrane permeability (0.9-fold), thereby down-regulating the expression of genes related to DNA uptake and processing (, , and , 0.7-0.8 folds). Importantly, CeO NPs exhibited an excellent binding capacity with the plasmids, decreasing the amounts of plasmids available for cellular uptake and down-regulating the gene expression of DNA uptake (, , and , 0.6-0.7 folds). Altogether, pre-exposure of plasmids with CeO NPs (10 and 25 mg L) suppressed the transformation with an efficiency of 44.5-51.6%. This study provides a nano-strategy for controlling the transformation of ARGs, improving our understanding on the mechanisms of nanomaterial-mediated ARGs propagation.
通过转化直接摄取细胞外DNA（eDNA）促进了抗生素抗性基因（ARGs）在环境中的传播。二氧化铈纳米颗粒（NPs）在调节以接合为主的ARGs传播方面具有潜力，而它们对ARGs转化的影响在很大程度上仍不清楚。在此，已应用浓度低于50 mg/L的二氧化铈纳米颗粒来调节质粒携带的ARGs向感受态（）细胞的转化。建立了三种类型的暴露系统以优化调节效率。用0.5 mg/L的二氧化铈纳米颗粒对感受态细胞进行预孵育，通过降低活性氧含量（0.9倍）和细胞膜通透性（0.9倍）抑制了转化（35.4%），从而下调了与DNA摄取和加工相关基因（、和，0.7 - 0.8倍）的表达。重要的是，二氧化铈纳米颗粒与质粒表现出优异的结合能力，减少了可用于细胞摄取的质粒数量，并下调了DNA摄取的基因表达（、和，0.6 - 0.7倍）。总之，用二氧化铈纳米颗粒（10和25 mg/L）对质粒进行预暴露以44.5 - 51.6%的效率抑制了转化。本研究提供了一种控制ARGs转化的纳米策略，增进了我们对纳米材料介导的ARGs传播机制的理解。
