title: Comparison of UV-Induced Inactivation and RNA Damage in MS2 Phage across the Germicidal UV Spectrum.
abstract: Polychromatic UV irradiation is a common method of pathogen inactivation in the water treatment industry. To improve its disinfection efficacy, more information on the mechanisms of UV inactivation on microorganisms at wavelengths throughout the germicidal UV spectrum, particularly at below 240 nm, is necessary. This work examined UV inactivation of bacteriophage MS2, a common surrogate for enteric pathogens, as a function of wavelength. The bacteriophage was exposed to monochromatic UV irradiation from a tunable laser at wavelengths of between 210 nm and 290 nm. To evaluate the mechanisms of UV inactivation throughout this wavelength range, RT-qPCR (reverse transcription-quantitative PCR) was performed to measure genomic damage for comparison with genomic damage at 253.7 nm. The results indicate that the rates of RNA damage closely mirror the loss of viral infectivity across the germicidal UV spectrum. This demonstrates that genomic damage is the dominant cause of MS2 inactivation from exposure to germicidal UV irradiation. These findings contrast those for adenovirus, for which MS2 is used as a viral surrogate for validating polychromatic UV reactors.
authors.affiliation: Department of Civil, Environmental, and Architectural Engineering, University of Colorado, Boulder, Colorado, USA.
authors.forename: Sara E
authors.initials: SE
authors.lastname: Beck
authors.affiliation: Department of Civil, Environmental, and Architectural Engineering, University of Colorado, Boulder, Colorado, USA.
authors.forename: Roberto A
authors.initials: RA
authors.lastname: Rodriguez
authors.affiliation: Department of Civil, Environmental, and Architectural Engineering, University of Colorado, Boulder, Colorado, USA.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Hawkins
authors.affiliation: Tetra Tech, Saint Albans, Vermont, USA.
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Hargy
authors.affiliation: National Institute of Standards and Technology, Gaithersburg, Maryland, USA.
authors.forename: Thomas C
authors.initials: TC
authors.lastname: Larason
authors.affiliation: Department of Civil, Environmental, and Architectural Engineering, University of Colorado, Boulder, Colorado, USA karl.linden@colorado.edu.
authors.forename: Karl G
authors.initials: KG
authors.lastname: Linden
mesh_terms: D004203:Disinfection / Q000379:methods; D017909:Levivirus / Q000502:physiology* / Q000528:radiation effects*; D050296:Microbial Viability / Q000528:radiation effects*; D012367:RNA, Viral / Q000528:radiation effects*; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014466:Ultraviolet Rays; D014871:Water Microbiology; D018508:Water Purification / Q000379:methods
chemical_list: D012367:RNA, Viral