Wang Yuwei, Gao Jingfeng, Duan Wanjun, Zhang Wenzhi, Zhao Yifan, Liu Jie
National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Beijing University of Technology, Beijing 100124, China.
National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Beijing University of Technology, Beijing 100124, China.
J Hazard Mater. 2020 Dec 5;400:123226. doi: 10.1016/j.jhazmat.2020.123226. Epub 2020 Jun 17.
The inactivation of a gram-negative sulfonamide antibiotic resistant bacteria (ARB) HLS.6 and removal of intracellular antibiotic resistance gene (ARG, sul1) and class I integrase gene (intI1) by nanoscale zero-valent iron (nZVI) and sulfide-modified nZVI (S-nZVI) with different S/Fe molar ratios were investigated in this study. The S-nZVI with high sulfur content (S/Fe = 0.05, 0.1, 0.2) was superior to nZVI and the treatment effect was best when S/Fe was 0.1. The ARB (2 × 10 CFU/mL) could be completely inactivated by 1.12 g/L of S-nZVI (S/Fe = 0.1) within 15 min, and the removal rates of intracellular sul1 and intI1 reached up to 4.39 log and 4.67 log at 60 min, respectively. Quenching experiments and flow cytometry proved that reactive oxygen species and adsorption were involved in the ARB inactivation and target genes removal. Bacterial death and live staining experiments and transmission electron microscopy showed that the ARB cell structure and intracellular DNA were severely damaged after S-nZVI treatment. This study provided a potential alternative method for controlling the antibiotic resistance in aquatic environment.
本研究考察了纳米零价铁（nZVI）和不同S/Fe摩尔比的硫化物改性纳米零价铁（S-nZVI）对革兰氏阴性磺胺类抗生素抗性细菌（ARB）HLS.6的灭活作用以及细胞内抗生素抗性基因（ARG，sul1）和I类整合酶基因（intI1）的去除情况。高硫含量的S-nZVI（S/Fe = 0.05、0.1、0.2）优于nZVI，且当S/Fe为0.1时处理效果最佳。1.12 g/L的S-nZVI（S/Fe = 0.1）可在15分钟内将ARB（2×10 CFU/mL）完全灭活，60分钟时细胞内sul1和intI1的去除率分别高达4.39 log和4.67 log。淬灭实验和流式细胞术证明，活性氧和吸附作用参与了ARB的灭活及靶基因的去除。细菌死亡和活染色实验以及透射电子显微镜显示，S-nZVI处理后ARB的细胞结构和细胞内DNA受到严重破坏。本研究为控制水环境中的抗生素抗性提供了一种潜在的替代方法。
