key: cord-1035014-yed3mnpa
authors: Pendyala, Brahmaiah; Patras, Ankit
title: Predicted UV-C Sensitivity of Human and Non-human Vertebrate (+) ssRNA Viruses
date: 2021-05-11
journal: bioRxiv
DOI: 10.1101/2021.05.10.443521
sha: f7d98101afb8c095ed7f54f50fdd0e5401d82c60
doc_id: 1035014
cord_uid: yed3mnpa

Epidemic and pandemic infectious diseases caused by RNA viruses constitute a significant hazard to human and animal health. Disinfection is an essential aspect of infection prevention and control measures. In this study, we estimated UV-C sensitivity of 83 human and veterinary pathogenic (+) ssRNA viruses by developed pyrimidine dinucleotide frequency-based genomic model. The data showed that the avian infectious bronchitis virus (genus: γ-coronavirus) with an estimated D90 value of 17.8 J/m2 was highly UV sensitive, whereas Salivirus NG-J1 (genus: salivirus) with a D90 value of 346.4 J/m2 was highly UV resistant. Overall, the trend of UV-C sensitivity of (+) ssRNA virus families followed as Coronaviridae < Flaviviridae < Togadoviridae < Arteriviridae, Matonaviridae, Astroviridae < Caciviridae < Picornaviridae < Nodaviridae < Herpeviridae. The results revealed that the enveloped viral families (Coronaviridae, Flaviviridae, Togadoviridae Arteriviridae, and Matonaviridae) are more UV-C sensitive than other nonenveloped families. Further validation of the model estimated UV sensitivity with literature available experimental data showed good agreement of predicted values. The estimates presented here could make it possible to reasonably predict UV-C disinfection efficiency of human and veterinary pathogenic viruses, which need specific biosafety requirements and/or difficult to cultivate in lab conditions.

Ten virus families whose members are pathogenic to humans and animals possess positivesense (+) single-stranded (ss) RNA genomes. The families Astroviridae, Caliciviridae, Picornaviridae, Nodaviridae and Hepeviridae are characterized by non-enveloped, whereas other families Coronaviridae, Flaviviridae, Togaviridae, Arteriviridae and Matonaviridae have enveloped capsids (https://viralzone.expasy.org/294). The spread and persistence of these pathogenic viruses in diverse environments, such as hospitals, residential, public areas, pet care facilities, animal sheds, animal husbandry, etc., emphasize developing efficient decontamination processes to control epidemic and pandemic outbreaks (Cozad and Jones, 2003) . Conventional chemical decontamination procedures are time-consuming, labor and resource-intensive, prone to high degrees of human error, and not applicable to air disinfection (McGinn et al., 2020) .

Alternative physical disinfection methods, such as germicidal ultraviolet light treatment, have gained importance due to their potential to disinfect air (Reed, 2010) and overwhelm the limitations mentioned above (McGinn et al., 2020) .

The germicidal ultraviolet light disinfection method uses UV-C light to disinfect microorganisms by damaging the nucleic acids, causing them to be unable to replicate and alters vital cellular functions (Patras et al., 2020) . It is well known that the disinfection level of microorganisms by UV-C light depends on their UV susceptibility, defined as D90 or D10 (dose for 90% inactivation or 10% survival) expressed as J/m2 or mJ/cm2 (Patras et al., 2020) . UV-C sensitivity of a wide range of microorganisms has been reported, including vegetative and spore forms of bacteria, yeast, fungi, protozoa, algae, and viruses (Malayeri et al., 2016; Gopisetty et al., 2019; Pendyala et al., 2019 Pendyala et al., , 2020a Pendyala et al., , 2021 . However, the UV-C sensitivity data for many (> 80 %) human and animal pathogenic viruses is not available due to the prerequisite for biosafety level (BSL)-3 containment and the need for specifically trained skilled labor and cultivation limitations in the laboratory environment (Pendyala et al., 2020b) . Acquiring the knowledge of UV susceptibility of target viruses is essential to deliver sufficient doses for efficient decontamination of the environment.

Our earlier study developed and validated a genome-sequence-based mathematical model (r 2 = 0.90) to predict the UV sensitivity and identify potential SARS-CoV-2 and human norovirus surrogates (Pendyala et al., 2020b) . This model was developed based on the pyrimidine dinucleotides frequency (PyNNF) of genome sequence, that effects the formation of pyrimidine dimers and 6-4 photoproducts and thereby UV susceptibility. The objective of the study was to estimate the UV-C sensitivity of 83 human and veterinary pathogenic viruses, belongs to all the families of (+) ssRNA viruses (Coronaviridae, Flaviviridae, Togadoviridae, Arteriviridae, Matonaviridae, Astroviridae, Caciviridae, Picornaviridae, Nodaviridae, Herpeviridae) by using developed pyrimidine dinucleotide frequency based mathematical model. Further validation of the model-predicted data by comparison with literature available experimental data.

We collected the genomic sequence of (+) ssRNA viruses belonging to families of Flaviviridae, Picornaviridae, Arteriviridae, Coronaviridae, Togaviridae, Retroviridae, Astroviridae, Calciviridae, Nodaviridae, Hepeviridae, and Matonaviridae. The size and nucleotide sequences of genomes used in this study were directly obtained from the available NCBI genome database (Table 1- Picornaviridae. Table 2 shows the predicted UV-C sensitivity of various genera of the picornaviviridae family. Bluegill picornavirus belongs to limnipivirus, was predicted to be highly UV sensitive with D90 of 33.2 J/m 2 , whereas salivirus NG-J1 was highly UV resistant (346.4 J/m 2 ).

The results revealed that the D90 values of major genus enterovirus and genera of hepatovirus, tremovirus, sapelovirus, avihepatovirus, avisvirus, and cosavirus was in the range of 47.9 -88 J/m 2 . Medium UV sensitivity (100.9 -125.7 J/m 2 ) was observed with genera teschovirus, erbovirus, rosavirus, dicipivirus, and cardiovirus. Suboptimal UV resistance with D90 171.9 to 267.7 J/m 2 was noticed with genera megrivirus, sicinivirus, kobuvirus, and sakobuvirus.

Arteriviridae and Coronaviridae. The families arteriviridae and coronaviridae are assigned to the order Nidovirales. The data show the coronaviridae family viruses were more UV sensitive (D90 17.8 -28.1 J/m 2 ) than arteriviridae viruses (D90 58.8 -81.2 J/m 2 ) ( Table 3 ). In coronaviridae, genus γ-coronavirus was noticed to be more UV sensitive (D90 17.8 J/m 2 ) and β-coronavirus (MERS coronavirus) was more UV resistant (D90 28.1 J/m 2 ). The λ-arterivirus and δ-arterivirus were identified as more UV sensitive and UV resistant genera in arteriviridae.

In this family, the genus alphavirus includes mosquito-borne human and veterinary pathogenic viruses. The model predicted UV D90 values were between 20.9 -40.9 J/m 2 , minimum with O'nyong-nyong virus and maximum with Venezuelan equine encephalitis virus (Table 4) . Rubella virus belongs to the genus rubivirus, and family matonaviridae had predicted D90 value of 65.5 J/m 2 .

Calciviridae. The estimated D90 of calciviridae family ranged from 65.7 -98.6 J/m 2 , and the genera lagovirus and nebovirus predicted with minimum and maximum D90 values (Table 5 ). The model predicted D90 values of human norovirus (HNoV) groups GI, GII and GIV were 69.1, 89.0, and 77.6 J/m 2 , respectively.

Nodaviridae. This family viruses comprised of are pathogenic to fish, comprised of two genera: α-nodavirus and β-nodavirus. The D90 data show the high resistance to UV (D90 varies from 118.4 -156.9 J/m 2 ), α-nodavirus more sensitive than β-nodavirus (Table 5) .

Astroviridae. The estimated UV sensitivity of two genera, mamastrovirus and avastrovirus were 58.5 and 59.3 J/m 2 , respectively (Table 5) .

Hepeviridae. Hepatitis E virus belongs to genus hepevirus had predicted D90 value of 247.2 J/m 2 , while other genus piscihepevirus (causes disease in fish) with lower D90 of 133.3 J/m 2 (Table 5) .

Though the developed genomic sequence-based parameter (PyNNFV) model may be sufficient to estimate UV-C susceptibility of viruses in many scenarios, the generation of more experimental data at specific regions (where the model does not have enough empirical data) is required to improve the accuracy of our predicted D90 values. In conclusion, our model predicted D90 values could be helpful to develop an efficient UV-C treatment process to achieve the target disinfection level of specific (+) ssRNA viruses where experimental UV-C sensitivity data is not available or feasible.

Note: There are no conflicts to declare effect on microbial inactivation, cytotoxicity, and sensory properties in cranberry-flavored water. Innovative Food Science & Emerging Technologies, 52, 66-74. Malayeri, A. H., Mohseni, M., Cairns, B., Bolton, J. R., Chevrefils, G., Caron, E., ... & Linden, K. G. (2016) . Fluence (UV dose) required to achieve incremental log inactivation of bacteria, protozoa, viruses and algae. IUVA News, 18 (3) 

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