Inactivation kinetics of 280 nm UV-LEDs against Mycobacterium abscessus in water

• Published in: Scientific reports Vol. 13; no. 1; p. 2186
• Main Authors: Song, Jack Jia Xin, Oguma, Kumiko, Takizawa, Satoshi
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 07-02-2023; Nature Publishing Group; Nature Portfolio
• Subjects: 631/326/171/1878; 631/326/421; 639/166/986; Biofilms; Disease resistance; Disinfectants; Disinfection; Disinfection & disinfectants; Disinfection - methods; Drinking water; Drinking Water - microbiology; Humanities and Social Sciences; Inactivation; Irradiation; Kinetics; Legionella pneumophila; Light emitting diodes; multidisciplinary; Mycobacterium abscessus; Nontuberculous Mycobacteria; Opportunist infection; Regrowth; Respiratory diseases; Science; Science (multidisciplinary); Ultraviolet radiation; Ultraviolet Rays; Water distribution; Water distribution systems; Water Microbiology; Water Purification - methods
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-023-29338-w

Nontuberculous mycobacteria (NTM) are opportunistic premise plumbing pathogens (OPPPs) that cause a burdensome waterborne respiratory disease. Due to their resistance to chemical disinfectants and regrowth in biofilms in drinking water distribution systems, treatment can be better performed using small ultraviolet disinfection units at the point-of-use (POU), such as at a tap or showerhead. Ultraviolet light-emitting diodes (UV-LEDs) are well suited for such applications, but fluence-response data are not available for one of the most important NTM,
Mycobacterium abscessus
. In this study, a bench-scale 280 nm UV-LED apparatus was used to irradiate
M. abscessus
in a water matrix. The fluence-response profile was sigmoidal, exhibiting both shoulder and tailing phenomena. Simple linear regression and the Geeraerd’s inactivation kinetics model yielded
k
values of 0.36 and 0.37 cm
2
/mJ, respectively, revealing that
M. abscessus
is more resistant to UV than
Pseudomonas aeruginosa
and
Legionella pneumophila
, which suggests that NTM are among the most UV-resistant OPPPs. Results of this study suggest that 280 nm UV-LED irradiation can be an effective and practical option to inactivate
M. abscessus
at the POU. Disinfection units that can deliver a fluence of 10 mJ/cm
2
are expected to achieve nearly 2 log (99%) inactivation of
M. abscessus
.