National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Faculty of Environment and Life, Beijing University of Technology, Beijing 100124, China.
National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Faculty of Environment and Life, Beijing University of Technology, Beijing 100124, China.
J Hazard Mater. 2022 Jun 15;432:128722. doi: 10.1016/j.jhazmat.2022.128722. Epub 2022 Mar 16.
Antibiotic resistance genes (ARGs) and antibiotic resistant bacteria (ARB) are widespread in urban wastewater treatment plants (UWTPs). In this research, a horizontal transfer model of recipient (Pseudomonas. HLS-6) and donor (Escherichia coli DH5α carries RP4 plasmid) was constructed to explore the effect of sulfidated nanoscale zerovalent iron (S-nZVI) on the efficiency of plasmid-mediated horizontal transfer. When the S/Fe was 0.1, the inactivation efficiency of 1120 mg/L S-nZVI on the donor and recipient bacteria were 2.36 ± 0.03 log and 3.50 ± 0.17 log after 30 min, respectively (initial ARB concentration ≈ 5 ×10 CFU/mL). Effects of treatment time, S/Fe molar ratio, S-nZVI dosage and initial bacterial concentration were systemically studied. S-nZVI treatment could increase the extracellular alkaline phosphatase and malondialdehyde content of the ARB, cause oxidative stress in the bacteria, destroy the cell structure and damage the intracellular DNA. This study provided evidence and insights into possible underlying mechanisms for reducing conjugative transfer, such as hindering cell membrane repair, inducing the overproduction of reactive oxygen species, inhibiting the SOS response, reducing the expression of ARGs and related transfer genes. S-nZVI could inhibit the gene conjugative transfer while inactivating the ARB. The findings provided an alternative method for controlling antibiotic resistance.
抗生素耐药基因（ARGs）和抗生素耐药菌（ARB）广泛存在于城市污水处理厂（UWTP）中。在这项研究中，构建了受体（假单胞菌。HLS-6）和供体（携带 RP4 质粒的大肠杆菌 DH5α）的水平转移模型，以探讨硫化纳米零价铁（S-nZVI）对质粒介导的水平转移效率的影响。当 S/Fe 为 0.1 时，1120mg/L S-nZVI 对供体和受体细菌的灭活效率分别为 2.36±0.03log 和 3.50±0.17log，作用 30min 后（初始 ARB 浓度约为 5×10 CFU/mL）。系统研究了处理时间、S/Fe 摩尔比、S-nZVI 剂量和初始细菌浓度的影响。S-nZVI 处理可增加 ARB 的细胞外碱性磷酸酶和丙二醛含量，引起细菌氧化应激，破坏细胞结构，损伤细胞内 DNA。本研究为减少接合转移的可能潜在机制提供了证据和见解，如阻碍细胞膜修复、诱导活性氧过度产生、抑制 SOS 反应、降低 ARGs 和相关转移基因的表达。S-nZVI 可以在灭活 ARB 的同时抑制基因的接合转移。研究结果为控制抗生素耐药性提供了一种替代方法。
