Narita Kouji, Fukushi Risako, Yamane Kyosuke, Okumura Yoshihiko, Koi Toru, Asano Krisana, Nakane Akio
Department of Microbiology and Immunology, Hirosaki University Graduate School of Medicine, Hirosaki, Japan.
Institution for Animal Experimentation, Hirosaki University Graduate School of Medicine, Hirosaki, Japan.
Appl Environ Microbiol. 2025 Feb 19;91(2):e0188624. doi: 10.1128/aem.01886-24. Epub 2025 Jan 31.
Ultraviolet (UV) C light emitted by a krypton chloride (KrCl) lamp consists of mainly less harmful 222-nm Far-UVC (unfiltered 222-mm Far-UVC) compared with conventionally used 254-nm UVC. It also contains wavelengths that are harmful to mammalian cells. By contrast, UVC from a KrCl lamp with optical filter (filtered 222-nm Far-UVC) consists of much less harmful 222-nm Far-UVC and is available for sterilization of dwelling spaces. The germicidal mechanisms of the 254-nm UVC and unfiltered 222-nm Far-UVC have been partially elucidated; however, the mechanism of action of filtered 222-nm Far-UVC remains unknown. It is known that 254 nm UVC induces cyclobutene pyrimidine dimers (CPDs), which are DNA lesions in (); however, the CPDs are repaired by photoreactivation. In the present study, it was demonstrated that filtered 222-nm Far-UVC also generated CPDs, which were not repaired by photoreactivation. Therefore, a germicidal mechanism of filtered 222-nm Far-UVC may be different from a 254-nm UVC. It was reported that unfiltered 222-nm Far-UVC induced reactive oxygen species (ROS) in . In the present study, filtered 222-nm Far-UVC also induced ROS production. In accordance with increased ROS production, the levels of carbonylated proteins were increased, and morphological alteration was observed in . From these results, it was suggested that ROS generated by filtered 222-nm Far-UVC inactivated ROS scavenger enzymes and the enzyme photolyase that is involved in photoreactivation. The increased ROS levels and unrepaired CPDs impaired photoreactivation in and may be involved in the germicidal mechanism of action of the filtered 222-nm Far-UVC.IMPORTANCEThe 222 nm Far-ultraviolet (UV) C light (UVC) emitted from a krypton chloride lamp with an optical filter is currently available for the sterilization of dwelling spaces. To use the filtered 222-nm Far-UVC more effectively and safely for sterilization, it is necessary to understand its germicidal mechanism. The present study suggests that the germicidal effect of filtered 222-nm Far-UVC on may not only involve CPD but also ROS. These results could be useful in establishing more effective preventive methods in dwelling spaces for infectious diseases by UVC irradiation.
与传统使用的254纳米紫外线相比，氪氯（KrCl）灯发出的紫外线C（UV）主要由危害较小的222纳米远紫外线C（未过滤的222毫米远紫外线C）组成。它还包含对哺乳动物细胞有害的波长。相比之下，带有光学滤光片的KrCl灯发出的紫外线C（过滤后的222纳米远紫外线C）由危害小得多的222纳米远紫外线C组成，可用于居住空间的杀菌。254纳米紫外线C和未过滤的222纳米远紫外线C的杀菌机制已得到部分阐明；然而，过滤后的222纳米远紫外线C的作用机制仍然未知。已知254纳米紫外线C会诱导环丁烷嘧啶二聚体（CPD），这是一种DNA损伤；然而，CPD可通过光复活修复。在本研究中，已证明过滤后的222纳米远紫外线C也会产生CPD，且不能通过光复活修复。因此，过滤后的222纳米远紫外线C的杀菌机制可能与254纳米紫外线C不同。据报道，未过滤的222纳米远紫外线C会在细胞中诱导活性氧（ROS）产生。在本研究中，过滤后的222纳米远紫外线C也会诱导ROS产生。随着ROS产生的增加，羰基化蛋白质水平升高，并在细胞中观察到形态改变。从这些结果表明，过滤后的222纳米远紫外线C产生的ROS使ROS清除酶和参与光复活的光解酶失活。ROS水平的升高和未修复的CPD损害了细胞中的光复活，可能参与了过滤后的222纳米远紫外线C的杀菌作用机制。
带有光学滤光片的氪氯灯发出的222纳米远紫外线C（UVC）目前可用于居住空间的杀菌。为了更有效、安全地使用过滤后的222纳米远紫外线C进行杀菌，有必要了解其杀菌机制。本研究表明，过滤后的222纳米远紫外线C对细胞的杀菌作用可能不仅涉及CPD，还涉及ROS。这些结果有助于通过紫外线照射在居住空间建立更有效的传染病预防方法。
