Validation of Phage T7 Biological Dosimeter by Quantitative Polymerase Chain Reaction Using Short and Long Segments of Phage T7 DNA¶

Hegedüs, M.; Módos, Károly; Rontó, Gy.; Fekete, Andrea

doi:10.1562/0031-8655(2003)078<0213:voptbd>2.0.co;2

Cited by 31 publications

(30 citation statements)

References 61 publications

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“…Alternatively, damage sustained by the proteins could be extended to the RNA in close proximity, causing RNA-protein cross-links or single-strand breaks. A previous study of the protein association of DNA showed that protein-associated DNA is more susceptible to UV damage than isolated DNA (35). UV-induced RNA-protein crosslinking has been described in the scientific literature (22).…”

Section: Resultsmentioning

confidence: 99%

Comparison of UV-Induced Inactivation and RNA Damage in MS2 Phage across the Germicidal UV Spectrum

Beck

Rodríguez

Hawkins

et al. 2016

Appl Environ Microbiol

149

123

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c 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. UV irradiation is a common method of disinfection in the water treatment industry. UV light induces damage to the genomes of bacteria, protozoa, and viruses, breaking bonds and forming photodimeric lesions in nucleic acids, DNA, and RNA (1, 2). These lesions prevent both transcription and replication and ultimately lead to inactivation of the microorganisms (3, 4). Direct UV damage to nucleic acids occurs at the wavelengths absorbed by DNA and RNA, in the germicidal UV region between 200 and 300 nm (5, 6). In this wavelength range, however, UV light also damages other cellular and viral components, causing, for example, photochemical reactions in proteins and enzymes (7,8). For this reason, UV sources that emit polychromatic light, across the germicidal UV spectrum, are considered more effective at inactivating certain pathogens than sources that emit monochromatic light at 253.7 nm (9-12). As polychromatic sources become more common, more research is being undertaken to understand the mechanisms of inactivation occurring in pathogens exposed to polychromatic UV irradiation.Male-specific (MS2) coliphage is a single-stranded RNA virus. It infects strains of Escherichia coli that produce F ϩ pili, which serve as viral receptors. The virion consists of a short singlestranded RNA genome (3,569 bases) surrounded by an icosahedral protein capsid, 27 nm in diameter (13). MS2 is commonly used in the water treatment industry as a surrogate for enteroviruses because of its similar size, shape, and genome composition (9,14). It serves as a biodosimeter for UV disinfection studies (15) and for UV reactor validation in North America (14, 16). For reactor validation, MS2 is also used as a surrogate for Cryptosporidium and adenovirus, despite the differences in UV sensitivity and spectral sensitivity between these microorganisms. Recent interest has grown regarding microbial ...

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Section: Resultsmentioning

confidence: 99%

Comparison of UV-Induced Inactivation and RNA Damage in MS2 Phage across the Germicidal UV Spectrum

Beck

Rodríguez

Hawkins

et al. 2016

Appl Environ Microbiol

149

123

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“…Similarly, a 437-base fragment has even been detected up to 350 mJ · cmϪ 2 (24). Several studies have attempted to correlate the degradation of the viral genome to the size of the detected fragment (8,11,23,27,28,29). All published reports on encapsidated poliovirus 1 RNA show that longer fragments (Ͼ800 bases) are at least equal to or more sensitive to UV or oxidation treatment (i.e., ozone, chlorine, chloramines, and chlorine dioxide) than are shorter fragments (Ͻ145 bases) (23,27,28,29).…”

Section: Discussionmentioning

confidence: 99%

Inactivation of Poliovirus 1 and F-Specific RNA Phages and Degradation of Their Genomes by UV Irradiation at 254 Nanometers

Simonet

Gantzer

2006

Appl Environ Microbiol

117

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Several models (animal caliciviruses, poliovirus 1 [PV1], and F-specific RNA bacteriophages) are usually used to predict inactivation of nonculturable viruses. For the same UV fluence, viral inactivation observed in the literature varies from 0 to 5 logs according to the models and the methods (infectivity versus molecular biology). The lack of knowledge concerning the mechanisms of inactivation due to UV prevents us from selecting the best model. In this context, determining if viral genome degradation may explain the loss of infectivity under UV radiation becomes essential. Thus, four virus models (PV1 and three F-specific RNA phages: MS2, GA, and Q␤) were exposed to UV radiation from 0 to 150 mJ · cm ؊2 . PV1 is the least-resistant virus, while MS2 and GA phages are the most resistant, with phage Q␤ having an intermediate sensitivity; respectively, 6-log, 2.3-log, 2.5-log, and 4-log decreases for 50 mJ · cm ؊2 . In parallel, analysis of RNA degradation demonstrated that this phenomenon depends on the fragment size for PV1 as well as for MS2. Long fragments (above 2,000 bases) for PV1 and MS2 fell rapidly to the background level (>1.3-log decrease) for 20 mJ · cm ؊2 and 60 mJ · cm ؊ 2 , respectively. Nevertheless, the size of the viral RNA is not the only factor affecting UV-induced RNA degradation, since viral RNA was more rapidly degraded in PV1 than in the MS2 phage with a similar size. Finally, extrapolation of inactivation and UV-induced RNA degradation kinetics highlights that genome degradation could fully explain UV-induced viral inactivation.Noroviruses, including the RNA genome, are nonculturable viruses of major concern for the safety of drinking water because they are an important cause of waterborne disease (14). Therefore, viral models should be used to estimate their loss of infectivity due to UV radiation. Depending upon the model virus (animal caliciviruses, enteric viruses such as poliovirus 1 [PV1], or RNA phages such as the MS2 phage) and the methods (infectivity versus molecular biology), the UV inactivation of human noroviruses can be estimated between 0 and 5 logs for a 20-mJ · cmϪ 2 fluence (1,5,6,12,21,25,34,35). Moreover, if only one model, such as animal caliciviruses, is considered, UV inactivation studies describe a 1.5-to 5-log unit decline for 20 mJ · cmϪ 2 for both feline and canine caliciviruses (5,6,25,34). Data obtained from these studies show a high variability for the UV susceptibility of viruses. The diversity of the proposed methods also highlights the lack of knowledge concerning the effect of UV on viral particles. Clear data will have to come forward defining the main parameter (i.e., genome size or capsid structure) responsible for viral inactivation before one or another approach can be favored.Although UV inactivates viruses by altering their genome or capsid, most inactivation studies have focused attention on the influence of radiation on DNA rather than on RNA genomes. Specific targets of UV have been demonstrated among the bases constituting the viral genome. In...

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“…The photoreversion can be added to the protective effect of water ice and various minerals surrounding the microorganisms [39,40] participating in their interplanetary transport. For the protective effect of short UV a further argument is [27]: found in the inactivation action spectrum of B. subtilis HA 101 spores (in the wavelength range 210 nm-290 nm) a decrease of the killing efficiency of the UV radiation at about 230 nm. This effect coincides with our results concerning the photoreversion.…”

Section: Discussionmentioning

confidence: 99%

“…The effects caused by the selected space parameters in the bacteriophage T7 and uracil thin film respectively, have been investigated with several methods: counting the survivor phage particles on infected Escherichia coli B host cells, determination of the UV absorption spectrum and the quantitative characteristics of the spectra [26], quantitative PCR (QPCR), enzymatic digestion, electrophoretic pattern [27,28], in addition, thin layer chromatography (TCL), mass spectroscopy of the photoproducts.…”

Section: Methodsmentioning

confidence: 99%

Biological ultraviolet Dosimetry in Low Earth’s Orbit

Egyeki¹

2013

Astrobiol Outreach

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The biological dosimetry of the solar UV radiation functioned correctly on the Earth's surface. The aim of the present studies was to extend the dosimetry to the extraterrestrial solar radiation in LEO. Similar to the Earth's surface bacteriophage T7 and polycrystalline uracil thin layers were used as detectors and exposed to the simulated and to the real space environmental parameters aiming to perform the in situ biological UV dosimetry in the space, more exactly on the external pallet of the ISS. The UV detectors have been used in specific cases in thin layer form. In contrast to the Earth's surface the extraterrestrial solar UV radiations contains wavelength components (λ ~ 190-200 nm), which cause photolesions (photoproducts) in the nucleic acids/their components similar to the UV-B photons. However, these wavelengths cause not only photolesions but with a wavelength-dependent efficiency the reversion of some photolesion, too. Our biological detectors measured either in simulation or in situ conditions the resultant of both reactions induced by the extraterrestrial UV radiation. From this aspect the role of the photoreversion in the extension of the biological UV dosimetry and in the survival of the living systems in the space are discussed.

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Validation of Phage T7 Biological Dosimeter by Quantitative Polymerase Chain Reaction Using Short and Long Segments of Phage T7 DNA¶

Cited by 31 publications

References 61 publications

Comparison of UV-Induced Inactivation and RNA Damage in MS2 Phage across the Germicidal UV Spectrum

Comparison of UV-Induced Inactivation and RNA Damage in MS2 Phage across the Germicidal UV Spectrum

Inactivation of Poliovirus 1 and F-Specific RNA Phages and Degradation of Their Genomes by UV Irradiation at 254 Nanometers

Biological ultraviolet Dosimetry in Low Earth’s Orbit

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