Background

Ultraviolet C (UVC) light has been used to inactivate several pathogens. Unlike conventional 254-nm UVC, 222-nm UVC is harmless to mammalian cells.

Aim

To investigate the disinfection efficacy of 222-nm UVC against human pathogens which are commonly found in the environment and healthcare facilities.

Methodology

Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Salmonella enterica subsp. serovar Typhimurium, Campylobacter jejuni, Bacillus cereus (vegetative cells and endospores), Clostridium sporogenes (vegetative cells and endospores), Clostoridioides difficile (endospores), Candida albicans (yeast), Aspergillus niger (hyphae and spores), Trichophyton rubrum (hyphae and spores), feline calicivirus and influenza A virus were irradiated with 222-nm UVC at various doses. The remaining live bacterial and fungal cells, and viral infectivity were evaluated. The germicidal effect of 222-nm UVC was compared with that of 254-nm UVC.

Results

UVC with a wavelength of 222 nm had a potent germicidal effect on vegetative bacterial cells, yeast and viruses, and was as efficient as 245-nm UVC. In addition, 222-nm UVC had a more potent germicidal effect on bacterial endospores compared with 254-nm UVC. The fungicidal effect of 222-nm UVC against fungal spores and hyphae was weaker than that of 254-nm UVC.

Conclusions

UVC with a wavelength of 222 nm was able to inactivate a wide spectrum of microbial pathogens. In comparison with 254-nm UVC, the germicidal effect of 222-nm UVC for fungal hyphae and spores was low, but 222-nm UVC had a strong germicidal effect on bacterial endospores.

中文翻译：

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波长 222 nm 的紫外线 C 光可灭活多种微生物病原体

 背景

紫外线 C (UVC) 光已被用来灭活多种病原体。与传统的 254 nm UVC 不同，222 nm UVC 对哺乳动物细胞无害。

 目的

研究 222 nm UVC 对环境和医疗机构中常见的人类病原体的消毒效果。

 方法

金黄色葡萄球菌、铜绿假单胞菌、大肠杆菌、肠沙门氏菌亚种。鼠伤寒血清型、空肠弯曲杆菌、蜡状芽孢杆菌（营养细胞和内生孢子）、产孢梭菌（营养细胞和内生孢子）、艰难梭菌（内生孢子）、白色念珠菌（酵母）、黑曲霉（菌丝和孢子）、红色毛癣菌（菌丝和孢子） ）、猫杯状病毒和甲型流感病毒用不同剂量的 222 nm UVC 进行照射。评估剩余的活细菌和真菌细胞以及病毒感染性。将 222 nm UVC 与 254 nm UVC 的杀菌效果进行比较。

 结果

波长为222 nm的UVC对细菌营养细胞、酵母菌和病毒具有强效杀菌作用，其杀菌效果与245 nm UVC相同。此外，与254 nm UVC相比，222 nm UVC对细菌内生孢子具有更有效的杀菌作用。 222 nm UVC 对真菌孢子和菌丝的杀菌作用弱于 254 nm UVC。

 结论

波长为 222 nm 的 UVC 能够灭活多种微生物病原体。与254 nm UVC相比，222 nm UVC对真菌菌丝和孢子的杀菌效果较低，但222 nm UVC对细菌内生孢子有较强的杀菌效果。