High-Throughput Sequencing Reveals Three Rhabdoviruses Persisting in the IRE/CTVM19 Cell Line

Cell cultures derived from ticks have become a commonly used tool for the isolation and study of tick-borne pathogens and tick biology. The IRE/CTVM19 cell line, originating from embryos of Ixodes ricinus, is one such line. Previously, reovirus-like particles, as well as sequences with similarity to rhabdoviruses and iflaviruses, were detected in the IRE/CTVM19 cell line, suggesting the presence of multiple persisting viruses. Subsequently, the full genome of an IRE/CTVM19-associated rhabdovirus was recovered from a cell culture during the isolation of the Alongshan virus. In the current work, we used high-throughput sequencing to describe a virome of the IRE/CTVM19 cell line. In addition to the previously detected IRE/CTVM19-associated rhabdovirus, two rhabdoviruses were detected: Chimay rhabdovirus and Norway mononegavirus 1. In the follow-up experiments, we were able to detect both positive and negative RNA strands of the IRE/CTVM19-associated rhabdovirus and Norway mononegavirus 1 in the IRE/CTVM19 cells, suggesting their active replication in the cell line. Passaging attempts in cell lines of mammalian origin failed for all three discovered rhabdoviruses.

SARS-CoV-2 evolution in a patient with secondary B-cell immunodeficiency: A clinical case

The article highlights the course of long-term SARS-CoV-2 infection in a patient with a secondary immunodeficiency developed with B-cell-depleting therapy of the underlying disease. Analysis of the intrapatient virus evolution revealed an inpatient S:G75A mutation that alters the 72GTNGTKR78 motif of the S-protein, with a possible role in binding to alternative cellular receptors. Therapy with a ready-made COVID-19-globulin preparation (native human immunoglobulin G (IgG) derived from the plasma of convalescent COVID-19-patients) resulted in rapid improvement of the patient's condition, fast, and stable elimination of the virus, and passive immunization of the patient for at least 30 days. The results suggest the use of products containing neutralizing antibodies opens new prospects for treatment algorithms for patients with persistent coronavirus infection, as well as for passive immunization schemes for patients with a presumably reduced specific response to vaccination.

Microbiological Characteristics of Some Stations of Moscow Subway

Simple Summary

Public transport facilities, including subway systems, provide the most suitable conditions for the transfer of microorganisms between people and the environment, contributing to the pathogenic potential of the urban habitat. Investigation of microbiome diversity and description of its characteristic properties, e.g., antibiotic-resistance profiles, leads to understanding of these interactions. In this study, we aimed to conduct an extended analysis of the bioaerosol and surface microbiome of the Moscow subway, using 16S rRNA gene sample sequencing and classical microbiology methods. The microbiomes of two subway stations (Novokosino and Cherkizovskaya) were reconstructed which differ in terms of passenger traffic and duration of exploitation. It was shown that most bacterial genera were ubiquitous; however, the unique genera were presented in aerosol samples. The relatively older Cherkizovskaya station possessed greater diversity in antibiotic resistance among the identified microorganisms compared to Novokosino station. We also provided a comparative analysis of these results with the previously published data, which allowed us to identify the distribution of microorganisms associated with the human microbiome and the environment regardless of the seasonal fluctuations. The obtained results provide valuable information on the diversity of bacterial communities in the Moscow subway, one of the most socially important facilities in metropolitan areas.

Abstract

The subway is one of the most actively used means of transport in the traffic infrastructure of large metropolitan areas. More than seven million passengers use the Moscow subway every day, which promotes the exchange of microorganisms between people and the surrounding subway environment. In this research, a study of the bacterial communities of two Moscow subway stations was conducted and the common subway microbiome was determined. However, there were differences in microbiological and antibiotic-resistance profiles, depending on the station. The station’s operational period since opening correlated with the taxonomic diversity and resistance of the identified bacteria. Moreover, differences between aerosol and surface bacterial communities were found at the two subway stations, indicating the importance of diversified sampling during the microbiome profiling of public areas. In this study, we also compared our data with previously published results obtained for the Moscow subway. Despite sample collection at different stations and seasons, we showed the presence of 15 common genera forming the core microbiome of the Moscow subway, which represents human commensal species, as well as widespread microorganisms from the surrounding environment.

Neutralizing Activity of Sera from Sputnik V-Vaccinated People against Variants of Concern (VOC: B.1.1.7, B.1.351, P.1, B.1.617.2, B.1.617.3) and Moscow Endemic SARS-CoV-2 Variants

Since the beginning of the 2021 year, all the main six vaccines against COVID-19 have been used in mass vaccination companies around the world. Virus neutralization and epidemiological efficacy drop obtained for several vaccines against the B.1.1.7, B.1.351 P.1, and B.1.617 genotypes are of concern. There is a growing number of reports on mutations in receptor-binding domain (RBD) increasing the transmissibility of the virus and escaping the neutralizing effect of antibodies. The Sputnik V vaccine is currently approved for use in more than 66 countries but its activity against variants of concern (VOC) is not extensively studied yet. Virus-neutralizing activity (VNA) of sera obtained from people vaccinated with Sputnik V in relation to internationally relevant genetic lineages B.1.1.7, B.1.351, P.1, B.1.617.2, B.1.617.3 and Moscow endemic variants B.1.1.141 (T385I) and B.1.1.317 (S477N, A522S) with mutations in the RBD domain has been assessed. The data obtained indicate no significant differences in VNA against B.1.1.7, B.1.617.3 and local genetic lineages B.1.1.141 (T385I), B.1.1.317 (S477N, A522S) with RBD mutations. For the B.1.351, P.1, and B.1.617.2 statistically significant 3.1-, 2.8-, and 2.5-fold, respectively, VNA reduction was observed. Notably, this decrease is lower than that reported in publications for other vaccines. However, a direct comparative study is necessary for a conclusion. Thus, sera from "Sputnik V"-vaccinated retain neutralizing activity against VOC B.1.1.7, B.1.351, P.1, B.1.617.2, B.1.617.3 as well as local genetic lineages B.1.1.141 and B.1.1.317 circulating in Moscow.

Geographical and Tick-Dependent Distribution of Flavi-Like Alongshan and Yanggou Tick Viruses in Russia

The genus Flavivirus includes related, unclassified segmented flavi-like viruses, two segments of which have homology with flavivirus RNA-dependent RNA polymerase NS5 and RNA helicase-protease NS3. This group includes such viruses as Jingmen tick virus, Alongshan virus, Yanggou tick virus and others. We detected the Yanggou tick virus in Dermacentor nuttalli and Dermacentor marginatus ticks in two neighbouring regions of Russia. The virus prevalence ranged from 0.5% to 8.0%. We detected RNA of the Alongshan virus in 44 individuals or pools of various tick species in eight regions of Russia. The virus prevalence ranged from 0.6% to 7.8%. We demonstrated the successful replication of the Yanggou tick virus and Alongshan virus in IRE/CTVM19 and HAE/CTVM8 tick cell lines without a cytopathic effect. According to the phylogenetic analysis, we divided the Alongshan virus into two groups: an Ixodes persulcatus group and an Ixodes ricinus group. In addition, the I. persulcatus group can be divided into European and Asian subgroups. We found amino acid signatures specific to the I. ricinus and I. persulcatus groups and also distinguished between the European and Asian subgroups of the I. persulcatus group.

A Case of Moderately Severe COVID-19 in a Healthcare Worker in Russia: Virus Isolation and Full Genome Sequencing

The coronavirus disease 2019 (COVID-19) pandemic is probably the most studied one in history from both clinical and molecular-epidemiological perspectives. Nonetheless, data on the correlation between severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral genotypes and COVID-19 symptoms caused by them are still scarce. In this report, we present a moderately severe COVID-19 case in a healthcare worker in Moscow, Russia, supplemented with the data on its causative agent's phenotype regarding in vitro and full-genome characterization. The 44-year-old male healthcare worker who had frequent professional contacts with COVID-19 patients was hospitalized with a viral pneumonia diagnosis and soon started to exhibit fever, dry paroxysmal cough, loss of smell, and typical ground-glass opacities found in both lungs on chest CT scans. The COVID-19 diagnosis was verified by real-time quantitative polymerase chain reaction (qRT-PCR), immunochromatography, and immunochemiluminescent assays. The patient was treated with hydroxychloroquine, azithromycin, paracetamol, and enoxaparin, leading to his recovery after two weeks from the disease onset. The virus was successfully isolated from the nasopharyngeal swab sample taken on the fifth day of the disease onset using the Vero E6 cell line and exhibited a pronounced cytopathic effect (CPE) with a viral titer reaching 10⁶ TCID₅₀/ml in the cell culture medium. The full genome sequence of the viral isolate was obtained and 8 nucleotide and 5 amino acid mutations compared to the Wuhan-Hu-1 reference genome were identified. Viral isolate belonged to GR / 20B / B.1.1 genetic lineage (GISAID, Nextstrain, Pangolin nomenclatures, respectively) - the most prevalent genotype found in Russia to date.

Full-genome analysis and pathogenicity of a genetically distinct Russian PRRSV-1 Tyu16 strain

Porcine reproductive and respiratory syndrome virus-1 (PRRSV-1) strains from Eastern Europe have a high diversity. All three known subtypes (1, 2, 3) of PRRSV-1 have been detected in Russia. There are two different groups of viruses belonging to the subtype 1: pan-European subtype 1 strains, and insufficiently studied Russian strains. The main objective of this study was to characterize the full genomic structure of the atypical Tyu16 strain of the Russian group subtype 1 PRRSV-1 and to assess its pathogenicity. Complete sequencing of the Tyu16 strain revealed that it did not belong to any existing subtype. Comparison of the whole genome sequence of the Tyu16 strain with that of PRRSV-1 prototype strains revealed 78.1 % (subtype 1 Lelystad), 78.1 % (subtype 2 WestSib13) and 77.7 % (subtype 3 Lena) nucleotide identity level, respectively. The coding sequence of different parts of the Tyu16 strain genome demonstrated a varying percentage identity to the different reference PRRSV-1 strains, which may indicate recombination events in its evolutionary history. We assume that among PRRSV-1 isolates, the Tyu16 is the closest relative to the common ancestor of PRRSV-1 and PRRSV-2. Low pathogenicity of the Tyu16 was demonstrated by experimental infection of 70-day-old piglets. Infected animals showed fever not exceeding 7 days, dyspnea in two out of five pigs and reduced weight gain. The virus shedding was undetectable and viremia was at low level.

Isolation and Characterisation of Alongshan Virus in Russia

In recent decades, many new flavi-like viruses have been discovered predominantly in different invertebrates and, as was recently shown, some of them may cause disease in humans. The Jingmenvirus (JMV) group holds a special place among flaviviruses and flavi-like viruses because they have a segmented ssRNA(+) genome. We detected Alongshan virus (ALSV), which is a representative of the JMV group, in ten pools of adult Ixodes persulcatus ticks collected in two geographically-separated Russian regions. Three of the ten strains were isolated in the tick cell line IRE/CTVM19. One of the strains persisted in the IRE/CTVM19 cells without cytopathic effect for three years. Most ALSV virions purified from tick cells were spherical with a diameter of approximately 40.5 nm. In addition, we found smaller particles of approximately 13.1 nm in diameter. We obtained full genome sequences of all four segments of two of the isolated ALSV strains, and partial sequences of one segment from the third strain. Phylogenetic analysis on genome segment 2 of the JMV group clustered our novel strains with other ALSV strains. We found evidence for the existence of a novel upstream open reading frame in the glycoprotein-coding segment of ALSV and other members of the JMV group.

Isolation and genetic characterization of encephalomyocarditis virus 1 from a deceased captive hamadryas baboon

In 2007, numerous hamadryas baboons (Papio hamadryas) died suddenly in an aviary of a primate institute in Sochi, Russia, in the absence of prior clinical signs. Necropsies were suggestive of encephalomyocarditis virus infection, but RT-PCR assays with commonly used primers were negative. Here we report the histopathological results obtained during necropsies and the isolation and genomic characterization of a divergent strain of encephalomyocarditis virus 1 (EMCV-1) from heart tissue of one of the succumbed hamadryas baboons. Phylogenetic analysis indicates that the isolated virus belongs to the newly proposed EMCV-1 lineage G, which clusters alongside lineage C ("Mengo virus"). This study is the first report describing a lineage G strain of EMCV-1 as the etiological agent of a lethal disease outbreak among captive nonhuman primates in Europe.

Genetic diversity of viruses of Chenuda virus species (Orbivirus, Reoviridae) circulating in Central Asia

Chenuda virus (CNUV) (Orbivirus, Reoviridae) is the only known orbivirus associated with argas (Argasidae) ticks. Scientific study of this group is necessary for understanding of Orbivirus genus evolution patterns. We conducted a comparative analysis of full genomes of five different viruses of Chenuda virus species, including Baku virus strains (BAKV) circulating in a rather limited area in the Central Asia and Transcaucasia. It was shown that VP4(OC1) and VP6(Hel) proteins variability greatly exceeds the variability of other proteins. The divergence between CNUV and BAKV in this proteins is about 50%. Even in closely related strains isolated from the same geographical region, the conservative genes of which are 90-95% identical, the VP4(OC1) and VP6(Hel) divergence reaches values that would usually be indicative of different serotypes (74.1-82.2%).

Reorganization and expansion of the nidoviral family Arteriviridae

The family Arteriviridae presently includes a single genus Arterivirus. This genus includes four species as the taxonomic homes for equine arteritis virus (EAV), lactate dehydrogenase-elevating virus (LDV), porcine respiratory and reproductive syndrome virus (PRRSV), and simian hemorrhagic fever virus (SHFV), respectively. A revision of this classification is urgently needed to accommodate the recent description of eleven highly divergent simian arteriviruses in diverse African nonhuman primates, one novel arterivirus in an African forest giant pouched rat, and a novel arterivirus in common brushtails in New Zealand. In addition, the current arterivirus nomenclature is not in accordance with the most recent version of the International Code of Virus Classification and Nomenclature. Here we outline an updated, amended, and improved arterivirus taxonomy based on current data. Taxon-specific sequence cut-offs are established relying on a newly established open reading frame 1b phylogeny and pairwise sequence comparison (PASC) of coding-complete arterivirus genomes. As a result, the current genus Arterivirus is replaced by five genera: Equartevirus (for EAV), Rodartevirus (LDV + PRRSV), Simartevirus (SHFV + simian arteriviruses), Nesartevirus (for the arterivirus from forest giant pouched rats), and Dipartevirus (common brushtail arterivirus). The current species Porcine reproductive and respiratory syndrome virus is divided into two species to accommodate the clear divergence of the European and American "types" of PRRSV, both of which now receive virus status. The current species Simian hemorrhagic fever virus is divided into nine species to accommodate the twelve known simian arteriviruses. Non-Latinized binomial species names are introduced to replace all current species names to clearly differentiate them from virus names, which remain largely unchanged.

Genetic and Phylogenetic Characterization of Tataguine and Witwatersrand Viruses and Other Orthobunyaviruses of the Anopheles A, Capim, Guamá, Koongol, Mapputta, Tete, and Turlock Serogroups

The family Bunyaviridae has more than 530 members that are distributed among five genera or remain to be classified. The genus Orthobunyavirus is the most diverse bunyaviral genus with more than 220 viruses that have been assigned to more than 18 serogroups based on serological cross-reactions and limited molecular-biological characterization. Sequence information for all three orthobunyaviral genome segments is only available for viruses belonging to the Bunyamwera, Bwamba/Pongola, California encephalitis, Gamboa, Group C, Mapputta, Nyando, and Simbu serogroups. Here we present coding-complete sequences for all three genome segments of 15 orthobunyaviruses belonging to the Anopheles A, Capim, Guamá, Kongool, Tete, and Turlock serogroups, and of two unclassified bunyaviruses previously not known to be orthobunyaviruses (Tataguine and Witwatersrand viruses). Using those sequence data, we established the most comprehensive phylogeny of the Orthobunyavirus genus to date, now covering 15 serogroups. Our results emphasize the high genetic diversity of orthobunyaviruses and reveal that the presence of the small nonstructural protein (NSs)-encoding open reading frame is not as common in orthobunyavirus genomes as previously thought.

[Taxonomic status of the Burana virus (BURV) (Bunyaviridae, Nairovirus, Tamdy group) isolated from the ticks Haemaphysalis punctata Canestrini et Fanzago, 1877 and Haem. concinna Koch, 1844 (Ixodidae, Haemaphysalinae) in Kyrgyzstan]

Complete genome sequence of the Burana virus (BURV) was determined using the next-generation sequencing approach (ID GenBank KF801651). The prototype strain of BURV LEIV-Krg760 was originally isolated from the ticks Haemaphysalis punctata Canestrini et Fanzago, 1877 (Ixodidae, Haemaphysalinae), collected from cows in Tokmak wildlife sanctuary, eastern part of the Chu valley (43 degrees 10' N, 74 degrees 40' E) near Burana village, Kirgizia, in April 1971. Molecular genetics and phylogenetic analyses showed that the BURV belonged to the Nairovirus genus, Bunyaviridae and is related to Tamdy virus (TAMV) that is also associated with the ixodidae ticks of pasture biocenosis in Central Asia. Previous studies showed that TAMV is the prototypic virus of new phylogenetic Tamdy group in the Nairovirus genus. Thus, BURV was classified as a new virus of the Tamdy group, Nairovirus, Bunyaviridae.

[Genetic characterization of the Wad Medani virus (WMV) (Reoviridae, Orbivirus), isolated from the ticks Hyalomma asiaticum Schulze et Schlottke, 1930 (Ixodidae: Hyalomminae) in Turkmenistan, Kazakhstan, and Armenia and from the ticks H. anatolicum Koch, 1844 in Tajikistan]

Near full-genome sequence of the Wad Medani Virus (WMV) (strain LEIV-8066Tur) (Orbivirus, Reoviridae) isolated from the ticks Hyalomma asiaticum Schulze et Schlottke, 1929, collected from sheep in Baharly district in Turkmenistan, was determined using next generation sequencing approach. The similarity of the RNA-dependent RNA-polymerase (Pol, VP1) amino acid sequence between WMV and the Kemerovo group orbiviruses (KEMV), as well as of the Baku virus (BAKV), was 64%. The similarity of the conserved structural protein VP3 (T2) of WMV with mosquito-borne and tick-borne orbiviruses reaches 46% and 67%, respectively. For the surface proteins VP2, VP5, and VP7 (T13), which have major antigenic determinants of orbiviruses, the similarity of WMV with tickborne orbiviruses (KEMV and BAKV) is 26-30%, 45% and, 57%, respectively (ID GenBank: KJ425426-35).

[Molecular genetic characterization of the Gissar virus (GSRV) (Bunyaviridae, Phlebovirus, Uukuniemi group) isolated from the ticks Argas reflexus Fabricius, 1794 (Argasidae) collected in dovecote in Tajikistan]

The Gissar virus (GSRV) was originally isolated from the ticks Argas reflexus, Fabricius, 1794 collected in a dovecote of Gissar village in Tajikistan (38 degrees 40' N, 68 degrees 40' E). Using electron microscopy, GSRV was classified to Bunyaviridae without referring to genus due to the absence of the antigenic relation with known bunyaviruses. In the present paper genome of GSRV was sequenced (MiSeq, Illumina). Molecular genetics and phylogenetic analysis showed. GSRV has a high level of homology with the Grand Arbaud Virus (GAV) (94% for nucleocapsid protein, 87.5% for RdRp, and 82% for the envelope proteins GnGc) isolated from the ticks A. Reflexus in a dovecote in France. GSRV and GAV have a narrow ecological niche associated with the icks A. Reflexus and birds (predominantly Columbidae). According to the conducted study, GSRV is classified as the topotypic for Central Asia variant of GAV, Uukuniemi group, genuses of the Phlebovirus (Bunyaviridae) (ID GenBank KJ425423, KJ425424, KJ425425).

[Genetic characterization of the Syr-Darya valley fever virus (SDVFV) (Picornaviridae, Cardiovirus) isolated from the blood of the patients and ticks Hyalomma as. asiaticum (Hyalomminae), Dermacentor daghestanicus (Rhipicephalinae) (Ixodidae) and Ornithodoros coniceps (Argasidae) in Kazakhstan and Turkmenistan]

The Syr-Darya valley fever virus (SDVFV) was originally isolated from the blood of the patient with fever in the Kyzylorda province, Kazakhstan, in July 1973 and was classified to the Cardiovirus genus (fam. Picornaviridae). Later, SDVFV was isolated from the ticks Hyalomma as. asiaticum Schulze et Schlottke, 1929 (Hyalomminae) (1 strain) and Dermacentor daghestanicus Olenev, 1929 (Rhipicephalinae) (7 strains), collected in the floodplains of the Syr-Darya river and the Ili river. In this paper, complet genome of the SDVFV (strain LEIV-Tur2833) was sequenced using the next-generation sequencing approach (GenBank ID: KJ191558). It was demonstrated that, phylogenetically, the SDVFV is closely related closest to the Theiler's murine encephalomyelitis virus (TMEV) and Vilyuisk human encephalomyelitis virus (VMEV). The similarity of the SDVFV with VHEV and TMEV based on P1 region of the polyprotein-precursor (structural proteins VP1-VP4), reaches 75% and 91% for nucleotide sequences and 80% and 93% for putative amino acid sequences, respectively. For nonstructural proteins regions P2 (2A-2C) and P3 (3A-3D) similarity of SDVFV with TMEV and VHEV is 96%-98%.

[Taxonomic status of the Chim virus (CHIMV) (Bunyaviridae, Nairovirus, Qalyub group) isolated from the Ixodidae and Argasidae ticks collected in the great gerbil (Rhombomys opimus Lichtenstein, 1823) (Muridae, Gerbillinae) burrows in Uzbekistan and Kazakhstan]

Full-length genome of the Chim virus (CHIMV) (strain LEIV-858Uz) was sequenced using the next-generation sequencing approach (ID GenBank: KF801656). The CHIMV/LEIV-858Uz was isolated from the Ornithodoros tartakovskyi Olenev, 1931 ticks collected in the great gerbil (Rhombomys opimus Lichtenstein, 1823) burrow in Uzbekistan near Chim town (Kashkadarinsky region) in July of 1971. Later, four more CHIMV strains were isolated from the O. tartakovskyi, O. papillipes Birula, 1895, Rhipicephalus turanicus Pomerantsev, 1936 collected in the great gerbil burrows in Kashkadarinsky, Bukhara, and Syrdarya regions of Uzbekistan, and three strains--from the Hyalomma asiaticum Schulze et Schlottke, 1930 from the great gerbil burrows in Dzheskazgan region of Kazakhstan. The virus is a potential pathogen of humans and camels. The phylogenetic analysis revealed that the CHIMV is a novel member of the Nairovirus genus (Bunyaviridae) and closely related to the Qalyub virus (QYBV), which is prototype for the group of the same name. The amino acid homology between the CHIMV and QYBV is 87% for the RdRp catalytic center (L-segment) that is coincident with both QYBV and CHIMV associated with the Ornithodoros ticks and burrow of rodents as well. The CHIMV homologies with other nairoviruses are 30-40% for the amino acid sequences of precursor polyprotein GnGc (M-segment), whereas 50%--for the nucleocapsid N (S-segment). The data obtained permit to classify the CHIMV as a member of the QYBV group in the genus of Nairovirus (Bunyaviridae).

[Taxonomic status of the Artashat virus (ARTSV) (Bunyaviridae, Nairovirus) isolated from the ticks Ornithodoros alactagalis Issaakjan, 1936 and O. verrucosus Olenev, Sassuchin et Fenuk, 1934 (Argasidae Koch, 1844) collected in Transcaucasia]

The Artashat virus (ARTSV) was originally isolated fom the Ornithodoros alactagalis Issaakjan, 1936 (Argasidae Koch, 1844), which were collected in the burrow of small five-toed jerboa (Allactaga elater Lichtenstein, 1825) in Armenia in 1972. Later, the ARTSV was isolated from the O. verrucosus Olenev, Sassuchin et Fenuk, 1934 collected in the burrows of Persian gerbil (Meriones persicus Blanford, 1875) in Azerbaijan. Based on the virion morphology, the ARTSV was assigned to the Bunyaviridae viruses. In this work, the ARTSV genome was partially sequenced (GenBank ID: KF801650) and it was shown that the ARTSV is a new member of the Nairovirus genus. ARTSV has from 42% (Issyk-Kul virus) to 58% (Raza virus, Hughes group) similarity with the nairoviruses for nucleotide sequence of part of RNA-dependent RNA-polymerase (RdRp). The similarity on the amino acid level is 65-70%. Low level of homology and the equidistant position of the ARTSV on phylogenetic tree indicate that the ARTSV is a new prototype species of the Nairovirus genus (Bunyaviridae) forming a separate phylogenetic branch.

[Genetic characterization of the Sakhalin virus (SAKV), Paramushir virus (PMRV) (Sakhalin group, Nairovirus, Bunyaviridae), and Rukutama virus (RUKV) (Uukuniemi group, Phlebovirus, Bunyaviridae) isolated from the obligate parasites of the colonial sea-birds ticks Ixodes (Ceratixodes) uriae, White 1852 and I. signatus Birulya, 1895 in the water area of sea of the Okhotsk and Bering sea]

Full-length genomes of the Sakhalin virus (SAKH) and Paramushir virus (PRMV) (Sakhalin group, Nairovirus, Bunyaviridae) isolated from the ticks Ixodes uriae White 1852 were sequenced using the next-generation sequencing (Genbank ID: KF801659, KF801656). SAKV and PRMV have 81% identity for the part of RNA-dependent RNA-polymerase (RdRp) on the nucleotide level and 98.5% on the amino acid level. Full-length genome comparison shows that SAKV have, in average, from 25% (N-protein, S-segment) to 50% (RdRp, L-segment) similarity with the nairoviruses. The maximum value of the amino acid similarity (50.3% for RdRp) SAKV have with the Crimean-Congo hemorrhagic fever virus (CCHFV) and Dugbe virus (DUGV), which are also associated with the Ixodidae ticks. Another virus studied is Rukutama virus (RUKV) (isolated from ticks I. signatus Birulya, 1895) that recently was classified (based on morphology and antigenic reaction) to the Nairovirus genus, presumably to the Sakhalin group. In this work the genome of the RUKV was sequenced (KF892052-KF892054) and RUKV was classified as a member of the Uukuniemi group (Phlebovirus, Bunyaviridae). RUKV is closely related (93.0-95.5% similarity) with our previously described Komandory virus (KOMV). RUKV and KOMV form separate phylogenetic line neighbor of Manawa virus (MWAV) isolated from the ticks Argas abdussalami Hoogstraal et McCarthy, 1965 in Pakistan. The value of the similarity between RUCV and MWAV is 65-74% on the amino acid level.

[Isolation of the Chikungunya virus in Moscow from the Indonesian visitor (September, 2013)]

The results of the virological identification of the Chikungunya fever case in Moscow (September, 2013) in an Indonesian visitor are presented. The clinic, electron microscopy, and molecular genetic data are discussed. The Ghikungunya virus (CHIKV) strain CHIKVILEIV-Moscow/1/2013 belonging to the Asian genotype (ID GenBank KF872195) was deposited into the Russian State Collection of viruses (GKV 1239; 18.11.2013).

[Molecular-genetic characterization of the Okhotskiy virus (OKHV) and Aniva virus (ANIV) (Orbivirus, Reoviridae) isolated from the ticks Ixodes (Ceratixodes) uriae White, 1852 in high latitudes of the Northern Eurasia]

Molecular-genetic characteristics of the Okhotskiy virus (OKHV) and Aniva virus (ANIV) were studied (ID GenBank KF981623-32). These viruses are distributed over the shelf and Island areas in the high latitudes in the Okhotsk, Bering, and Barents seas and linked with nesting colonies of Alcidae seabirds and their obligatory parasites, the Ixodes uriae (Ixodidae) ticks. OKHV and ANIV are observed to be independent species within the limits of the Great Island virus (GIV) group of the Orbivirus genus of the Reoviridae family. The majority of the genes of OKHV and ANIV have high homology (VP1 - 96%, T2 - 99%, VP7 (T13) - 98%, NS1 - 94%, NS2 - 98%, NS3 - 72%, VP6 - 93%). Nevertheless, the envelope proteins containing the main specific antigenic determinants (VP2 and VP5) of OKHV and ANIV are sufficiently different (62% and 68% homology for amino acid sequences, respectively).

[Taxonomy of previously unclassified Tamdy virus (TAMV) (Bunyaviridae, Nairovirus) isolated from the Hyalomma asiaticum asiaticum Schülce et Schlottke, 1929 (Ixodidae, Hyalomminae) in the Middle East and transcaucasia]

Complete genome sequencing of three Tamdy (TAMV) virus strains was carried out. The prototype strain TAMV/LEIV-1308Uz was isolated for the very first time from the Hyalomma asiaticum asiaticum Schülce et Schlottke, 1929 (Ixodidae, Hyalomminae) collected in the August 1971 from sheep in the arid area near Namdybulak town (41 degrees 36' N, 64 degrees 39' E) in the Tamdinsky district of the Bukhara region (Uzbekistan). TAMV was revealed to be a prototype member of the new phylogenetic group within the limits of the Nairovirus. The TAMV homology for RdRp (L-segment) amino acid sequence is not less than 40% with Crimea-Congo hemorrhagic fever virus (CCHFV), Hazara virus (HAZV), and Dugbe virus (DUGV), which are also linked with Ixodidae ticks. The TAMV homologies with the Issyk-Kul virus (ISKV) and Caspiy virus (CASV) for RdRp are 37.6% and 37.7%, respectively. These data conformed to the low values of GnGc (M-segment) and nucleocapsid protein N (S-segment) homology. The TAMV homologies with the nairoviruses for GnGc is in average 25%; with the nairoviruses linked with Ixodidae ticks (CCHFV, DUGV, HAZV) - 33%; with Argasidae ticks (ISKV, CASV) - 28%. The TAMV/LEIV-1308Uz, LEIV-6158Ar, and LEIV-10226Az have high level of identity. The TAMV/LEIV-10226Az from Azerbaijan has 99% homology for both nucleotide and amino acid sequences of the prototype TAMV/LEIV-1308Uz RdRp. The TAMV/LEIV-6158Ar from Armenia is more divergent and has 94.2% and 96.3% homologies with the TAMV/LEIV-1308Uz, respectively. The homology between the TAMV/LEIV-1308Uz and TAMV/LEIV-10226Az for GnGc is 93%. The TAMV/LEIV-6158Ar has 90% homology for this protein with the TAMV/LEIV-1308Uz and 93% with the TAMV/LEIV-10226Az, respectively. Differences in nucleocapsid protein between three TAMV strains are 5-7%.

[Genetic characterization of the Batken virus (BKNV) (Orthomyxoviridae, Thogotovirus) isolated from the Ixodidae ticks Hyalomma marginatum Koch, 1844 and the mosquitoes Aedes caspius Pallas, 1771, as well as the Culex hortensis Ficalbi, 1889 in the Central Asia]

The prototype strain LEIV-K306 of the Batken virus (BKNV) was isolated from the Ixodidae ticks Hyalomma marginatum Koch, 1844 collected from sheep near town Batken (Kirgizstan) in the April 1970. Later, the BKNV was isolated in Kirgizstan from the mixed pool of the Aedes caspius Pallas, 1771 and Culex hortensis Ficalbi, 1889 mosquitoes. From the very beginning, the BKNV was discussed to be very close to the Dhori virus (DHOV) (Orthomyxoviridae, Thogotovirus) isolated from the Ixodidae ticks Hyalomma dromedarii Koch, 1844 in India. In this work, virtually complete genome sequence (MiSeq, Illumina) of the BKNV was determined (ID GenBank KJ396672-4). Structural and non-structural proteins of the BKNV have a high level of homology with DHOV - 98% (PB1) and 96% (PB2, PA, NP, M). Homology of HA protein between the BKNV and DHOV is 90%, which accounts for antigenic difference between these close relative viruses. Since the differences in the other structural and non-structural proteins are about 96-98%, the BKNV could be suggested as the topotypic DHOV strain for Central Asia, Transcaucasia, and Northern Caspian region. The evolution divergence of the BKNV and DHOV for HA could be explained by local ecologic peculiarities of the BKNV areal.

[Taxonomic status of the Tyulek virus (TLKV) (Orthomyxoviridae, Quaranjavirus, Quaranfil group) isolated from the ticks Argas vulgaris Filippova, 1961 (Argasidae) from the birds burrow nest biotopes in the Kyrgyzstan]

The Tyulek virus (TLKV) was isolated from the ticks Argas vulgaris Filippova, 1961 (Argasidae), collected from the burrow biotopes in multispecies birds colony in the Aksu river floodplain near Tyulek village (northern part of Chu Valley, Kyrgyzstan). Recently, the TLKV was assigned to the Quaranfil group (including the Quaranfil virus (QRFV), Johnston Atoll virus (JAV), Lake Chad virus) that is a novel genus of the Quaranjavirus in the Orthomyxoviridae family. In his work, the complete genome (ID GenBank KJ438647-8) sequence of the TLKV was determined using next-generation sequencing (Illumina platform). Comparison of deduced amino acid sequences shows closed relationship of the TLKV with QRFV and JAV (86% and 84% identity for PB1 and about 70% for PB2 and PA, respectively). The identity level of the TLKV and QRFV in outer glycoprotein GP is 72% and 80% for nucleotide and amino acid sequences, respectively. The phylogenetic analysis showed that the TLKV belongs to the genus of the Quaranjavirus in the family Orthomyxoviridae.

[Genetic characterization of viruses from the antigenic complex Tyuleniy (Flaviviridae, Flavivirus): Tyuleniy virus (TYUV) (ID GenBank KF815939) isolated from ectoparasites of colonial seabirds--Ixodes (Ceratixodes) uriae White, 1852, ticks collected in the high latitudes of Northern Eurasia--and Kama virus (KAMV) isolated from the Ixodes lividus Roch, 1844, collected in the digging colonies of the middle part of Russian plane]

Genetic research into the Tyuleniy virus (TYUV) (ID GenBank KF815939) isolated in high latitudes from the Ixodes uriae White, 1852, ticks collected in the nesting colonies of the Alcidae (Leach, 1820) birds and Kama virus (KAMV) (ID GenBank KF815940) isolated from the I. lividus ticks collected in the nesting bird colonies in the middle part of the Russian Plane was carried out. Full-genome comparative analysis revealed 70% homology between KAMV and TYUV on the nucleotide level and 74% on the amino acid level. Thus, KAMV is a new member of the TYUV complex belonging to the seabird tick-borne virus group (STBVG) of Flavivirus (Flaviviridae). KAMV is a separate virus and forms separate phylogenetic line together with the TYUV, Meaban virus (MEAV), and Saumarez Reef virus (SREV).

[Taxonomy of the Sokuluk virus (SOKV) (Flaviviridae, Flavivirus, Entebbe bat virus group) isolated from bats (Vespertilio pipistrellus Schreber, 1774), ticks (Argasidae Koch, 1844), and birds in Kyrgyzstan]

Complete genome sequencing of the Sokuluk virus (SOKV) isolated in Kyrgyzstan from bats Vespertilio pipistrellus and their obligatory parasites--Argasidae Koch, 1844, ticks was carried out. SOKV was classified as attributed to the Flaviviridae family, Flavivirus genus. The maximum homology (71% for nucleotide and 79% for amino acid sequences) was detected with respect to the Entebbe bat virus (ENTV). ENTV and SOKV form a group joining to the yellow fever virus (YFV) within the limits of the mosquito flavivirus branch. Close relation of SOKV with bat covers and human housings permits to assume SOKV potentially patogenic to human health.

[Genetic characterization of the Uzun-Agach virus (UZAV, Bunyaviridae, Nairovirus), isolated from bat Myotis blythii oxygnathus Monticelli, 1885 (Chiroptera; Vespertilionidae) in Kazakhstan]

The complete genome of Uzun-Agach virus (UZAV), isolated from the liver of Myotis blythii oxygnathus (Monticelli, 1885 (Chiroptera; Vespertilionidae)) bats in Alma-Ata district (Kazakhstan) in 1977 have been sequenced. Based on full-length genome comparison it is shown that UZAV is a new member of the Nairovirus genus (family Bunyaviridae). L-segment and M-segments of UZAV have 69,3% and 64,1% identity with Issyk-Kul virus (ISKV) that also was isolated from bats. S-segment of UZAV have 99,6% identity with the same of ISKV. This allow us to claim that UZAV is a reassortant virus that have S-segment derived from ISKV, and L- and M-segments from another virus that is phylogenetically related to ISKV, but divergent from it. The obtained data that the reassortment between ISKV and UZAV exists in nature suggest that they cocirculated in one ecological niche (bats of the Vespertilionidae family) and the areal of UZAV may coincide with the areal of ISKV.

[Genetic characterization of the Caspiy virus (CASV) (Bunyaviridae, Nairovirus) isolated from the Laridae (Vigors, 1825) and Sternidae (Bonaparte, 1838) birds and the Argasidae (Koch, 1844) ticks Ornithodoros capensis Neumann, 1901, in Western and Eastern coasts of the Caspian Sea]

Full-genome sequencing of the Caspiy virus (CASV - Caspiy virus) (ID GenBank KF801658) revealed its attribution to the Nairovirus genus of the Bunyaviridae family as a separate species. CASV forms separate line, which is the most close to the Hughes virus (HUGV) and Sakhalin virus (SAKV) groups containing viruses linked with seabirds and ticks parasitizing on them and distributed over the shelf and island ecosystems in the Northern Eurasia, as well as the North and South America.

[Genetic characterization of the Geran virus (GERV, Bunyaviridae, Nairovirus, Qalyub group) isolated from the ticks Ornithodoros verrucosus Olenev, Zasukhin and Fenyuk, 1934 (Argasidae) collected in the burrow of Meriones erythrourus Grey, 1842 in Azerbaijan]

The full-length genome of the unclassified Geran virus (GERV, strain LEIV-10899Az) isolated from the ticks (Ornithodoros verrucosus Olenev, Zasukhin and Fenyuk, 1934 (Argasidae, Ornithodorinae)) collected in the burrow of the red-tailed gerbils (Meriones (Cricedidae) erythrourus Grey, 1842) near the Geran station (Azerbaijan) was sequenced using the next-generation approach (GenBank ID: KF801649). It was shown that the GERV is a new representative of the Nairovirus genus (family Bunyaviridae). The comparative analysis of the full-length genome sequences of the GERV with other nairoviruses showed that the highest level of homology (55.6% for N protein (S-segment) of 54.2% for the polyprotein Gn/Gc (M-segment) and 74.8% for the RNA-dependent RNA polymerase (L-segment)) GERV had with the Chim virus (CHIMV) that is also associated with the shelters biocenoses (rodent burrows) in Central Asia and was previously assigned to the Qalyub virus group (QYBV). Comparing the GERV with the QYBV sequences (partial sequence 413 n.o. of RdRp gene) revealed a high level of homology: 74.3 and 97.4% for the nucleotide and amino acid sequences, respectively. The data obtained in this work provided an opportunity to classify the GERV to the QYBV group; the Nairovirus genus, to the family Bunyaviridae.

[Complete genome characterization of the Kyzylagach virus (KYZV) (Togaviridae, Alphavirus, Sindbis serogroup) isolated from mosquitoes Culex modestus Ficalbi, 1889 (Culicinae) collected in a colony of herons (Ardeidae Leach, 1820) in Azerbaijan]

Complete genome sequencing of the Kyzylagach virus (KYZV) LEIV-65A strain isolated from the Culex modestus Ficalbi, 1889 (Culicinae), which was collected in the colony of the Ardeidae Leach, 1820 birds on the coast of Caspian sea, Kyzyl-Agach bay, in the southern part of Azerbaijan, was carried out. KYZV has high homology (about 99%) with the Chinese XJ-160 strain of the Sindbis virus (SINV) isolated from Anopheles sp. in Xinjiang Uyghur autonomic region (north-eastern China). Homologies of KYZV and XJ-160 with European SINV strains are 82% and 93% for the nucleotide and amino acid sequences, respectively (GenBank ID: KF981618). The difference between the nucleotide sequences of KYZV and Australian SINV/SW6562 strain is 19%; amino acid sequences, 12%. Since XJ-160 strain is extremely similar to KYZV, the first could be considered as the KYZV strain. The geography of the KYZV and XJ-160 isolation points and their genetic distance from the European viruses allow the KYZV to be suggested as a SINV (genotype IV) topotypic variant typical of Transcaucasia and Central Asia.

[Genetic characterization of the Zaliv Terpeniya virus (ZTV, Bunyaviridae, Phlebovirus, Uukuniemi serogroup) strains isolated from the ticks Ixodes (Ceratixodes) uriae White, 1852, obligate parasites of the Alcidae birds, in high latitudes of Northern Eurasia and the mosquitoes Culex modestus Ficalbi, 1889, in subtropics Transcaucasus]

Complete genome sequences were obtained for the LEIV-13841Ka (ID GenBank KF767463-65) and LEIV-279Az (ID GenBank KF767460-62) virus strains, which were classified as different strains of the Zaliv Terpeniya virus (ZTV). LEIV-13841Ka was isolated from the ticks Ixodes (Ceratixodes) uriae White, 1852 collected on Ariy Kamen (Commander Islands) in 1986. LEIV-279Az was isolated from the mosquitoes Culex modestus Ficalbi, 1889, collected in heron colony (Ardea Linnaeus, 1758) in Azerbaijan (1969) and was initially identified as Uukuniemi virus (UUKV). According to the results obtained LEIV-279Az is ZTV strain as well. LEIV-13841Ka and LEIV-279Az RdRp sequences have high level of homology (99%) with previously sequenced ZTV/LEIV-271Ka. The L-segment nucleotide sequences are homological with ZTV/LEIV-271Ka on the level of 94% and 98% for LEIV-13841Ka and LEIV-279Az, respectively; M-segment--89% and 88%, respectively. Such homologies for the amino acid sequences of Gn/Gc polyprotein are 98.3% and 97.7%. NP proteins of ZTV/LEIV-13841Ka and LEIV-279Az have 88.7% and 84.6% homologies with ZTV/LEIV-271Ka both for amino acid and nucleotide sequences, respectively. Thus, for the very first time we demonstrated ZTV strain isolated from mosquitoes in subtropical Transcaucasia zone. Obtained results permit to expand suggested areal of ZTV and to fill up data upon the ecology of the Uukuniemi virus group.

[Complete genome analysis of the Batai virus (BATV) and the new Anadyr virus (ANADV) of the Bunyamwera group (Bunyaviridae, Orthobunyavirus) isolated in Russia]

Almost complete nucleotide sequences for the S, M, and L segments were obtained for three strains of the Batai virus (Bunyamwera serogroup, genus Orthobunyavirus, Bunyaviridae family). Based on the results of the phylogenetic analysis conducted forthe three genomic segments LEIV Ast507 and LEIV-Ast528 strains were grouped with other European BATV isolates and were found to be almost identical to the strain 42 isolated from Volgograd Region, Russia, 2003. Surprisingly, LEIV-13395 strain isolated from the Aedes sp. mosquitos in Magadan Oblast, 1987, turned out to be a novel genotype inside Bunyamwera serogroup. The highest nucleotide identity levels of LEIV-13395 genomicsegments (86.9%, 80.8%, 79.7% for S, M and L segments respectively) were observed with corresponding segments of the Batai virus.

[The taxonomy of the Baku virus (BAKV; Reoviridae, Orbivirus) isolated from the birds obligate parasites Argasidae ticks in Azerbaijan, Turkmenistan, and Uzbekistan]

The Baku virus (BAKV) was originally isolated from the ticks Ornithodoros capensis Neumann, 1901 (Acari: Argasidae) collected from the seagull (Larus argentatus) seating nests on the islands of the Baku archipelago, the Caspian sea. BAKV was assigned to Kemerovo group (KEMV) (Orbivirus, Reoviridae). The BAKV was frequently isolated from the ticks O. coniceps Canestrini, 1980, collected from L. argentatus and tern (Sterna hirundo) nests in Turkmenia and pigeon (Columba livia neglecta) nests in Uzbekistan. In this work, the genome of the BAKV was sequenced using the next-generation sequencing technology. The BAKV Pol protein has 48.6% identity level with the viruses of the Great Island Virus group and at average 41% with non-tick orbiviruses. The BAKV T2 protein level identity with the orbiviruses ranges from 23.7% to 64.8%. The maximum identity level of the T2 protein (64.8%) is observed for the tick-borne viruses of the GIV (KEMV) group. According to the conducted molecular-genetic and phylogenetic analysis, the BAKV is a novel species of the genus Orbivirus. It forms a phylogenetic group distinctly related to the GIV group.

[Genetic characterization of new Komandory virus (KOMV; Bunyaviridae, Phlebovirus) isolated from the ticks Ixodes uriae, collected in guillemot (Uria aalge) nesting sites on Komandorski islands, the Bering sea]

Unclassified virus named Komandory virus (KOMV) isolated in Komandorski islands from the ticks Ixodes uriae in 1986 was partially sequenced. The KOMV nucleocapsid (N) protein sequence shows 30-40% identity level with the mosquito-borne phleboviruses and 43% with the Uukuniemi virus (UUKV) group (Phlebovirus, Bunyaviridae). The maximum identity (65%) for the KOMV N protein is observed for the Manawa virus. The KOMV glycoprotein identity with the UUKV group viruses ranges from 45% to 59%. The KOMV RdRp identity with the Manawa virus reaches 74%, while showing 63% level at average with the other UUKV group viruses. According to the results of molecular-genetic and phylogenetic analysis, the KOMV is a new member of the UUKV group (Phlebovirus, Bunyaviridae).

[The taxonomy of the Khasan virus (KHAV), a new representative of phlebovirus genera (Bunyaviridae), isolated from the ticks haemaphysalis longicornis (Neumann, 1901) in the Maritime Territory (Russia)]

The Khasan virus (KHAV) was originally isolated in Khasansky District and Maritime Territory in 1971 from the ticks Haemophysalis longicornis (Neumann, 1901) collected from the deers Cervus nippon (Temmink, 1838). Based on the biological properties and virion morphology, KHAV was identified as an unclassified member of the Bunyaviridae family. In order to elucidate the KHAV taxonomy in more detail, viral genome was partially sequenced using the next-generation sequencing technology. According to the phylogenetic analysis conducted for partial sequences of the three genome segments, KHAV was attributed to the genus Phlebovirus. KHAV is phylogenetically mostly related to the viruses of the Uukuniemi group and has up to 62% identity with them. The maximum identity level is observed for sequences of the RNA-dependent-RNA-polymerase (RdRp) gene. The KHAV homology level with the tick-borne Uukuniemi group viruses is 50 to 62%; however, for the mosquito-borne phleboviruses it does not exceed 30%.

[The taxonomy of the Issyk-Kul virus (ISKV, Bunyaviridae, Nairovirus), the etiologic agent of the Issyk-Kul fever isolated from bats (Vespertilionidae) and ticks Argas (Carios) vespertilionis (Latreille, 1796)]

The Issyk-Kul virus (etiological agent of the Issyk-Kul fever) was originally isolated from bats (Nyctalus noctula Schreber, 1774 (Chiroptera: Vespertilionidae)) and their parasites ticks (Argas (Carios) vespertilionis Latreille, 1796 (Parasitiformes: Argasidae)) in Kirghizia. Sporadic cases and epidemics of the Issyk-Kul fever are observed in Central Asia since 1979. The ISKV genome was de novo sequenced using the next-generation sequencing technology. According to the molecular-genetic and phylogenetic analysis, the ISKV is a member of a novel group in the genus Nairovirus (Bunyaviridae). Based on the data obtained, molecular-genetic methods can be used for ISKV detection (PCR) for the Issyk-Kul fever monitoring and diagnosis in the endemic areas.

[The Khurdun virus (KHURV): a new representative of the orthobunyavirus (Bunyaviridae)]

Unidentified Khurdun virus (KHURV) was isolated in 2001 from coot (Fulica atra, Linnaeus, 1758) in the Volga River delta (Astrakhan Region, Russian Federation). Here we report that the KHUV genome was de novo sequenced (on Illumina platform) and the KHURV was classified as a novel prototypic bunyavirus. The KHURV genome comprises three negative-sense RNA segments (L, M, and S); its terminal nucleotide sequences are canonical for the Orthobunyavirus genus. Based on the results of the molecular-genetic and phylogenetic analysis we suggest that the KHURV belongs to the genus Orthobunyavirus (Bunyaviridae).

[Molecular-genetic characterization of the Bhanja virus (BHAV) and the Razdan virus (RAZV) (Bunyaviridae, Phlebovirus) isolated from the Ixodes ticks Rhipicephalus bursa (Canestrini and Fanzago, 1878) and Dermacentor marginatus (Sulzer, 1776) in transcaucasus]

Two bunyaviruses, Bhanja (BHAV, LEIV-Az1818) isolated from the Ixodes ticks Rhipecephalus bursa (Canestrini and Fanzago, 1878) in Azerbaijan (1973) and Razdan (RAZV; strain LEIV-Arm2741) isolated from the Dermacentor marginatus (Sulzer, 1776) ticks in Armenia (1972), were de novo sequenced (on the Illumina platform). The amino acid identity between these viruses proteins were 95.8% (RdRp, L-segment), 90.3% (GnGc, M-segment), and 92.5% (N, S-segment). Thus, RAZV was classified to BHAV group. GnGc protein identity of RAZV withEuropean BHAV strains is more than 90%. With the African Forécariah virus (FORV) RAZV has 85% identity. BHAV LEIV-Az1818 is most closely related to the Indian strain BHAV IG690 (99%), while showing 90% identity with the European BHAV isolates. The genome structure of BHAV and RAZV is typical of the tick-transmitted phleboviruses. Based onthe result of the molecular-genetic and phylogenetic analysis RAZV has been classified as belonging to BHAVgroup in the genus Phlebovirus (Bunyaviridae).