质粒介导的接合转移促进抗生素抗性的传播,然而,管理这一进程的全面监管机制仍然遥不可及。在这里,我们建立了纯细菌和活性污泥结合系统来研究结合转移的调节机制,利用二甲双胍作为外源性制剂。转录组学分析揭示了与双组分系统相关的基因的大幅上调(例如,AcrB/AcrA,EnvZ/Omp,和CpxA/CpxR)暴露于二甲双胍后。此外,双组分系统的下游调节器,包括活性氧(ROS),细胞质膜通透性,和三磷酸腺苷(ATP)的生产,分别提高了1.7、1.4和1.1倍,分别,与对照组相比,在0.1mg/L二甲双胍暴露下。此外,流分选和高通量测序表明,活性污泥系统中跨结合体之间的微生物群落多样性增加。值得注意的是,人类致病菌的抗菌潜力(例如,拟杆菌,大肠杆菌志贺氏菌,和乳酸杆菌)被增强,对人类健康构成潜在威胁。我们的发现揭示了抗生素抗性细菌的传播,并评估了与废水处理系统中质粒介导的接合转移相关的生态风险。
Plasmid-mediated conjugative transfer facilitates the dissemination of antibiotic resistance, yet the comprehensive regulatory mechanisms governing this process remain elusive. Herein, we established pure bacteria and activated sludge conjugation system to investigate the regulatory mechanisms of conjugative transfer, leveraging metformin as an exogenous agent. Transcriptomic analysis unveiled that substantial upregulation of genes associated with the two-component system (e.g., AcrB/AcrA, EnvZ/Omp, and CpxA/CpxR) upon exposure to metformin. Furthermore, downstream regulators of the two-component system, including reactive oxygen species (ROS), cytoplasmic membrane permeability, and adenosine triphosphate (ATP) production, were enhanced by 1.7, 1.4 and 1.1 times, respectively, compared to the control group under 0.1 mg/L metformin exposure. Moreover, flow sorting and high-throughput sequencing revealed increased microbial community diversity among transconjugants in activated sludge systems. Notably, the antibacterial potential of human pathogenic bacteria (e.g., Bacteroides, Escherichia-Shigella, and Lactobacillus) was augmented, posing a potential threat to human health. Our findings shed light on the spread of antibiotic resistance bacteria and assess the ecological risks associated with plasmid-mediated conjugative transfer in wastewater treatment systems.