Persister cells are difficult to eliminate because they are tolerant to antibiotic stress. In the present study, using artificially induced Escherichia coli persister cells, we found that reactive oxygen species (ROS) have greater effects on persister cells than on exponential cells. Thus, we examined which types of ROS could effectively eliminate persister cells and determined the mechanisms underlying the effects of these ROS. Ultraviolet (UV) light irradiation can kill persister cells, and bacterial viability is markedly increased under UV shielding. UV induces the production of ROS, which kill bacteria by moving toward the shielded area. Electron spin resonance-based analysis confirmed that hydroxyl radicals are produced by UV irradiation, although singlet oxygen is not produced. These results clearly revealed that ROS sterilizes persister cells more effectively compared to the sterilization of exponential cells (^**p < 0.01). These ROS do not injure the bacterial cell wall but rather invade the cell, followed by cell killing. Additionally, the sterilization effect on persister cells was increased by exposure to oxygen plasma during UV irradiation. However, vapor conditions decreased persister cell sterilization by reducing the levels of hydroxyl radicals. We also verified the effect of ROS against bacteria in biofilms that are more resistant than planktonic cells. Although UV alone could not completely sterilize the biofilm bacteria, UV with ROS achieved complete sterilization. Our results demonstrate that persister cells strongly resist the effects of antibiotics and starvation stress but are less able to withstand exposure to ROS. It was shown that ROS does not affect the cell membrane but penetrates it and acts internally to kill persister cells. In particular, it was clarified that the hydroxy radical is an effective sterilizer to kill persister cells.

持久性细胞难以消除，因为它们可以耐受抗生素的压力。在本研究中，使用人工诱导大肠杆菌对于持久性细胞，我们发现活性氧（ROS）对持久性细胞的影响大于对指数细胞的影响。因此，我们检查了哪些类型的ROS可以有效消除持久性细胞，并确定了这些ROS的潜在作用机理。紫外线（UV）可以杀死持久性细胞，并且在紫外线屏蔽下细菌活力显着提高。紫外线会诱导产生ROS，并通过向屏蔽区域移动来杀死细菌。基于电子自旋共振的分析证实，尽管不产生单重态氧，但是通过紫外线照射产生了羟基自由基。这些结果清楚地表明，与对指数细胞进行灭菌相比，ROS更有效地对持久性细胞进行了灭菌（^**p<0.01）。这些ROS不会损伤细菌细胞壁，而是侵入细胞，然后杀死细胞。另外，通过在紫外线照射期间暴露于氧等离子体，提高了对持久性细胞的灭菌效果。但是，蒸汽条件通过减少羟基自由基的含量而减少了持久性细胞的灭菌。我们还验证了ROS对比浮游细胞更具抵抗力的生物膜中细菌的作用。尽管仅靠紫外线不能完全对生物膜细菌进行灭菌，但使用ROS的紫外线可以实现完全灭菌。我们的研究结果表明，持久性细胞强烈抵抗抗生素和饥饿压力的影响，但抵御ROS的能力较弱。结果表明，ROS不会影响细胞膜，但会穿透细胞膜并在内部发挥作用，杀死持久性细胞。