摘要
      水环境中抗生素耐药性的扩散可能导致抗生素治疗失败，已引起全世界的关注。然而，基于紫外线的高级氧化过程对抗生素抗性细菌（ARB）失活和抗生素抗性基因（ARGs）降解的影响尚未得到很好的研究。本研究旨在比较研究紫外线和紫外线/H2O2对耐万古霉素粪肠球菌（VRE）的灭活作用及其对含vanB基因的降解效果。结果表明，VRE在UV和UV/H2O2过程中都很容易失活。尽管UV/H2O2在VRE灭活方面仅略优于单独的UV，但它显著抑制了细菌的光活化和再生。UV/H2O2确实实现了细胞内vanB的协同降解（0.1–0.8 log），这可以通过增加紫外线强度、降低pH和分批添加H2O2来进一步增强。自由基dotOH的诱导增强导致细胞膜损伤，促进过量自由基dotOH-的进入，并更有效地氧化释放的细胞内ARGs。总体而言，腐殖酸的存在抑制了VRE的失活和vanB的降解，而较低浓度的腐殖酸（2.5–5 mg/L）可以作为自由基引发剂，并略微促进UV/H2O2过程中vanB的分解。我们的研究结果表明，与单独使用紫外线相比，UV/H2O2在控制ARB和细胞内ARG方面具有更多优势。
Abstract
The proliferation of antibiotic resistance in water environment which may cause antibiotic therapy failure has attracted worldwide attention. However, the effects of UV-based advanced oxidation processes on inactivation of antibiotic resistant bacteria (ARB) and degradation of antibiotic resistance genes (ARGs) have not been well studied. This study aimed to comparatively investigate the removal efficacy in inactivating the vancomycin-resistant Enterococcus faecalis (VRE) and degrading its containing vanB gene under exposure to UV and UV/H2O2. The results showed that VRE was readily inactivated in both UV and UV/H2O2 processes. Although UV/H2O2 was only slightly superior to UV alone in VRE inactivation, it significantly inhibited the bacterial photoactivation and regrowth. UV/H2O2 indeed achieved synergistic degradation of intracellular vanB (0.1–0.8 log), which could be further enhanced by increasing the UV intensity, lowering pH and adding H2O2 in batches. The enhanced induction of radical dotOH resulted in the cell membrane damage, facilitating the entrance of excess radical dotOH and more efficiently oxidizing the released intracellular ARGs. Overall, the presence of humic acid inhibited the inactivation of VRE and degradation of vanB, while lower concentrations of humic acid (2.5–5 mg/L) could act as free radical initiator and slightly promoted vanB degradation in UV/H2O2 process. Our findings suggested that UV/H2O2 has more advantages on the control of ARB and intracellular ARGs compared to UV alone.

https://www.sciencedirect.com/science/article/abs/pii/S2214714422004482