2 research outputs found
Wavelength-Dependent Damage to Adenoviral Proteins Across the Germicidal UV Spectrum
Adenovirus,
a waterborne pathogen responsible for causing bronchitis,
pneumonia, and gastrointestinal infections, is highly resistant to
UV disinfection and therefore drives the virus disinfection regulations
set by the U.S. Environmental Protection Agency. Polychromatic UV
irradiation has been shown to be more effective at inactivating adenovirus
and other viruses than traditional monochromatic irradiation emitted
at 254 nm; the enhanced efficacy has been attributed to UV-induced
damage to viral proteins. This research shows UV-induced damage to
adenoviral proteins across the germicidal UV spectrum at wavelength
intervals between 200 and 300 nm. A deuterium lamp with bandpass filters
and UV light-emitting diodes (UV LEDs) isolated wavelengths in approximate
10 nm intervals. Sodium dodecyl sulfate polyacrylamide gel electrophoresis
and image densitometry were used to detect signatures for the hexon,
penton, fiber, minor capsid, and core proteins. The greatest loss
of protein signature, indicating damage to viral proteins, occurred
below 240 nm. Hexon and penton proteins exposed to a dose of 28 mJ/cm<sup>2</sup> emitted at 214 nm were approximately 4 times as sensitive
and fiber proteins approximately 3 times as sensitive as those exposed
to a dose of 50 mJ/cm<sup>2</sup> emitted at 254 nm. At 220 nm, a
dose of 38 mJ/cm<sup>2</sup> reduced the hexon and penton protein
quantities to approximately 33% and 31% of the original amounts, respectively.
In contrast, a much higher dose of 400 mJ/cm<sup>2</sup> emitted at
261 and 278 nm reduced the original protein quantity to between 66–89%
and 80–93%, respectively. No significant damage was seen with
a dose of 400 mJ/cm<sup>2</sup> at 254 nm. This research directly
correlates enhanced inactivation at low wavelengths with adenoviral
protein damage at those wavelengths, adding fundamental insight into
the mechanisms of inactivation of polychromatic germicidal UV irradiation
for improving UV water disinfection
Wavelength Dependent UV Inactivation and DNA Damage of Adenovirus as Measured by Cell Culture Infectivity and Long Range Quantitative PCR
Adenovirus is regarded as the most
resistant pathogen to ultraviolet
(UV) disinfection due to its demonstrated resistance to monochromatic,
low-pressure (LP) UV irradiation at 254 nm. This resistance has resulted
in high UV dose requirements for all viruses in regulations set by
the United States Environmental Protection Agency. Polychromatic,
medium-pressure (MP) UV irradiation has been shown to be much more
effective than 254 nm, although the mechanisms of polychromatic UV
inactivation are not completely understood. This research analyzes
the wavelength-specific effects of UV light on adenovirus type 2 by
analyzing in parallel the reduction in viral infectivity and damage
to the viral genome. A tunable laser from the National Institute of
Standards and Technology was used to isolate single UV wavelengths.
Cell culture infectivity and PCR were employed to quantify the adenoviral
inactivation rates using narrow bands of irradiation (<1 nm) at
10 nm intervals between 210 and 290 nm. The inactivation rate corresponding
to adenoviral genome damage matched the inactivation rate of adenovirus
infectivity at 253.7 nm, 270 nm, 280 nm, and 290 nm, suggesting that
damage to the viral DNA was primarily responsible for loss of infectivity
at those wavelengths. At 260 nm, more damage to the nucleic acid was
observed than reduction in viral infectivity. At 240 nm and below,
the reduction of viral infectivity was significantly greater than
the reduction of DNA amplification, suggesting that UV damage to a
viral component other than DNA contributed to the loss of infectivity
at those wavelengths. Inactivation rates were used to develop a detailed
spectral sensitivity or action spectrum of adenovirus 2. This research
has significant implications for the water treatment industry with
regard to polychromatic inactivation of viruses and the development
of novel wavelength-specific UV disinfection technologies