Xin Kuan, Chen Xingdu, Zhang Zigeng, Zhang Zhiqiang, Pang Heliang, Yang Jing, Jiang Hui, Lu Jinsuo
School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China.
School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China; State Key Laboratory of Green Building in West China, Xi'an University of Architecture and Technology, Xi'an 710055, China.
J Hazard Mater. 2022 Jun 15;432:128634. doi: 10.1016/j.jhazmat.2022.128634. Epub 2022 Mar 5.
Sewer is considered a potential hotspot for antibiotic resistance, but the occurrence and proliferation of antibiotic resistance genes (ARGs) under trace antibiotics exposure have received little attention. This work evaluated the effects of tetracycline (TC) and sulfamethoxazole (SMX) individually and in combination in the sewer system and revealed the related mechanisms of ARG proliferation. The relative abundance of tetA and sul1 increased the most under TC and SMX stress, respectively, whereas sul1 increased the most under combined stress. Intl1 was abundant in both the liquid phase and the biofilm, and redundancy analysis confirmed that horizontal gene transfer was the main reason for the proliferation of ARGs. The increase in extracellular polymeric substances (EPS) secretion and the enhancement of the main hydrophobic functional groups facilitated the accumulation of biofilms, which promoted the proliferation of ARGs in biofilms. The relative abundance of most ARGs in the liquid phase was significantly correlated with EPS, protein and tryptophan-like substances. Furthermore, the microbial community structure and diversity affected the proliferation and spread of ARGs in the sewer. These findings contribute to our further understanding of the proliferation and development of ARGs in the sewer and lay the foundation for the front-end control of ARGs.
下水道被认为是抗生素耐药性的潜在热点，但在痕量抗生素暴露下抗生素耐药基因（ARGs）的发生和增殖却很少受到关注。这项工作评估了四环素（TC）和磺胺甲恶唑（SMX）单独及联合作用于下水道系统的影响，并揭示了ARGs增殖的相关机制。tetA和sul1的相对丰度分别在TC和SMX胁迫下增加最多，而sul1在联合胁迫下增加最多。整合酶1（Intl1）在液相和生物膜中均大量存在，冗余分析证实水平基因转移是ARGs增殖的主要原因。胞外聚合物（EPS）分泌的增加和主要疏水官能团的增强促进了生物膜的积累，进而促进了生物膜中ARGs的增殖。液相中大多数ARGs的相对丰度与EPS、蛋白质和类色氨酸物质显著相关。此外，微生物群落结构和多样性影响了下水道中ARGs的增殖和传播。这些发现有助于我们进一步了解下水道中ARGs的增殖和发展，并为ARGs的前端控制奠定基础。
