College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; School of Life Science, Jinggangshan University, Ji'an 343009, China.
School of Life Science, Jinggangshan University, Ji'an 343009, China.
J Environ Sci (China). 2024 Jan;135:161-173. doi: 10.1016/j.jes.2022.11.014. Epub 2022 Dec 2.
Antibiotic resistance genes (ARGs) can be easily promoted by antibiotics, however, the structural effects of antibiotics on the proliferation of ARGs dynamic and the associated mechanisms remain obscure in, especially, activated sludge sequencing batch reactors. In the present study, the effects of 9 sulfonamides (SAs) with different structures on the proliferation dynamic of sulfonamide resistance genes (Suls) in the activated sludge sequencing batch reactors and the corresponding mechanisms were determined (30 days), and the results showed that the largest proliferation value (∆A) of Suls dynamic for SAs (sulfachloropyridazine) was approximately 2.9 times than that of the smallest one (sulfadiazine). The proliferation of Suls was significantly related to the structural features (minHBint6, SssNH, SHBd and SpMax2_Bhm) that represent the biological activity of SAs. To interpret the phenomenon, a mechanistic model was developed and the results indicated that the biodegradation of SAs (T) rather than conjugative transfer frequency or mutation frequency tends to be the key process for affecting Suls proliferation. T was proved to be dependent on the interactions between SAs and receptors (E), the cleavage mode (bond dissociation energy), and the site of nucleophilic assault. Besides, the metagenomic analysis showed that SAs posed significant effect on antibiotic resistome and Tnp31 played a vital role in the proliferation of Suls. Overall, our findings provide important insight into a theoretical basis for understanding the structural effects of SAs on the proliferation of ARGs in SBR systems.
抗生素抗性基因 (ARGs) 很容易被抗生素促进，然而，抗生素对 ARGs 动态增殖的结构影响及其相关机制在，特别是，活性污泥序批式反应器中仍然不清楚。在本研究中，确定了 9 种结构不同的磺胺类抗生素 (SAs) 对活性污泥序批式反应器中磺胺类抗性基因 (Suls) 增殖动态的影响及其相应机制 (30 天)，结果表明，Suls 动态的最大增殖值 (∆A) 对于 SAs (磺胺氯哒嗪) 大约是最小的一个 (磺胺嘧啶) 的 2.9 倍。Suls 的增殖与结构特征 (minHBint6、SssNH、SHBd 和 SpMax2_Bhm) 显著相关，这些特征代表了 SAs 的生物活性。为了解释这一现象，建立了一个机制模型，结果表明，SAs 的生物降解 (T) 而不是共轭转移频率或突变频率往往是影响 Suls 增殖的关键过程。T 被证明依赖于 SAs 和受体 (E) 之间的相互作用、裂解模式 (键离解能) 和亲核攻击的位置。此外，宏基因组分析表明，SAs 对抗生素抗性组有显著影响，Tnp31 在 Suls 的增殖中起着至关重要的作用。总的来说，我们的研究结果为理解 SAs 对 SBR 系统中 ARGs 增殖的结构影响提供了重要的理论基础。
