Far-UVC light (222 nm) efficiently inactivates clinically significant antibiotic-resistant bacteria on diverse material surfaces
Authors: Huang Jhen-Rong , Yang Tsai-Wen , Hsiao Ya-I , Fan Hui-Min , Kuo Han-Yueh , Hung Kuo-Hsiang , Chen Po-Yen , Tan Ching-Ting , Shao Pei-Lan 
Published: October 2024

ABSTRACT

In recent years, there has been a gradual increase in the prevalence of drug-resistant bacteria, primarily attributed to the widespread use of antibiotics. This has resulted in heightened mortality rates, morbidity, and exorbitant healthcare costs associated with antibiotic-resistant bacterial infections. In order to mitigate the spread of antibiotic-resistant bacteria, environmental disinfection plays a crucial role. Ultraviolet radiation C (UVC) light disinfection has emerged as a potent technique to limit the transmission of nosocomial pathogens and prevent healthcare-associated infections. Different types of high-touch surfaces were used. A serial disinfected experiment with different 222 nm UVC dosages was conducted on clinically isolated antibiotic-resistant bacteria, including methicillin-resistant
Staphylococcus aureus
(MRSA), vancomycin-resistant
Enterococcus
species (VRE), carbapenem-resistant
Escherichia coli
(CREC), carbapenem-resistant
Klebsiella pneumonia
(CRKP), carbapenem-resistant
Acinetobacter baumannii
(CRAB), and carbapenem-resistant
Pseudomonas aeruginosa
(CRPA) on different material surfaces. The bactericidal efficacy was evaluated by The Clinical & Laboratory Standards Institute (CLSI) guidelines. 222 nm UVC irradiation had a potent bactericidal efficacy on clinical antibiotic-resistant bacteria on different high-touch surfaces that are commonly found in the environment and healthcare facilities. 222 nm UVC irradiation time was tested from 10 s to 1 h. Different surfaces affect the efficiency of 222 nm UVC. The more adsorptive a material is, the higher the dosage of 222 nm UVC irradiation energy is required for effective disinfection. The use of 222 nm UVC lamps for disinfection on different materials has been shown to be a useful method. However, it is crucial to pay attention to the energy required for effective sterilization.

IMPORTANCE
This study is crucial, providing compelling evidence on Far-ultraviolet radiation C (Far-UVC) light’s efficacy against clinically significant antibiotic-resistant bacteria—a pressing issue in microbiology and infection control. Our research employs antibiotic-resistant strains from clinically isolated bacteria, emphasizing real-world relevance. Simultaneously, we assess Far-UVC light (222 nm) across diverse material surfaces commonly found in clinical settings. This dual approach ensures practical applicability and broad relevance. Our comprehensive setup and rigorous methodologies unequivocally demonstrate Far-UVC light’s potency in combating antibiotic-resistant bacteria. Since 222 nm far-UVC has a disinfection capability and is harmless to mammalian cells, this dual effectiveness positions Far-UVC as a secure tool for infection control, with potential applications in healthcare settings, mitigating antibiotic-resistant bacteria spread, and reducing healthcare-associated infections.