摘要
      抗生素抗性基因（ARGs）和抗生素抗性细菌（ARB）在城市污水处理厂（UWTP）中广泛存在。本研究构建了受体（假单胞菌.HLS-6）和供体（大肠杆菌DH5α携带RP4质粒）的水平转移模型，以探讨硫化纳米级零价铁（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±0.03 log和3.50±0.17 log（初始ARB浓度≈5×107CFU/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。这项研究为减少偶联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、诱导活性氧的过量产生、抑制SOS反应、减少ARGs和相关转移基因的表达。S-nZVI可以抑制基因偶联转移，同时使ARB失活。这些发现为控制抗生素耐药性提供了一种替代方法。
Abstract
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 ×107 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.

https://www.sciencedirect.com/science/article/abs/pii/S0304389422005118