[The analysis of immunoreactivity of individual B-cell epitopes of hepatitis C virus (Flaviviridae: Hepacivirus: Hepatitis С virus) NS4a antigen].

INTRODUCTION: Chronic viral hepatitis C (CHC) is a ubiquitous infectious disease, a significant limitation of which WHO attributes to the use of a new highly effective antiviral therapy. Previously, two B-cell epitopes were identified in NS4a antigen of the hepatitis C virus (HCV). It was shown that certain titers of antibodies (ABs) to the extended C-terminal epitope (1687-1718 a.a.) can predict a high probability of achieving a sustained virological response (SVR) to standard therapy with pegylated interferon-α and ribavirin.The aim of the work was to determine immunoreactivity of two B-cell epitopes (middle and C-terminal) of NS4a antigen, and to estimate a possible association of ABs to them with the achievement of SVR after standard interferon therapy and treatment with direct antiviral drugs (DAAs) daclatasvir and sofosbuvir (velpanat). MATERIALS AND METHODS: Blood serum samples of patients with CHC (n = 113), of which 55 participants received standard interferon therapy, 50 received velpanate treatment, the remaining 8 received no therapy were examined. The middle B-cell epitope (positions 24-34 a.a.) of NS4a was synthesized by the solid-phase method, while the C-terminal epitope (34-54 a.a.) was obtained using genetically engineered techniques. Enzyme immunoassay (ELISA) testing of the sera collected before treatment was performed for the two selected epitopes according to the conventional methods. RESULTS: The antibodies to the C-terminal epitope were detected significantly more frequently than those to the middle one (p = 0.01) when analyzing the blood sera of patients (n = 113). The presence of ABs to the C-terminal epitope in the serum samples of participants who completed standard interferon therapy was associated with the achievement of SVR (p = 0.0245). In the blood sera of participants who completed therapy with velpanate, an association of the presence of ABs to the C-terminal epitope with the achievement of SVR was also established (p < 0.0001). The presence of ABs to the middle B epitope was not associated with the achievement of SVR, regardless of the therapy used. DISCUSSION: The observed difference in the immunoreactivity of the two B-cell determinants may be associated with the localization of the nearest Th-epitopes, the sensitivity of NS4a antigen to proteolytic enzymes, and the peculiarities of epitope presentation by antigen-presenting cells. However, it should be noted that the immunoreactivity of the middle B-epitope is poorly studied. Although the association of ABs to the C-terminal epitope with the achievement of SVR has been shown by several scientific teams, the detailed molecular mechanism of their influence on the effectiveness of therapy is unclear. CONCLUSION: In CHC, ABs to the C-terminal epitope of NS4a are produced more frequently than those to the median epitope. The presence of ABs to the C-terminal epitope is a predictive marker of a high probability of achieving SVR, regardless of the type of therapy and antibody titer.

Modification of the Spike Protein for Vaccines against Enveloped RNA Viruses.

Most vaccines work by inducing neutralizing antibodies that target the viral envelope. Enveloped RNA viruses have evolved mechanisms for surface glycoproteins to evade host immune responses, which exhibit substantial variability, even among different strains. Natural infection and vaccines using native forms of surface proteins may induce broadly neutralizing antibodies, yet with low and ineffective levels. Class I membrane-fusion proteins of enveloped RNA viruses, HIV-1, influenza A virus, SARS-CoV-2, yield a stable conformation (so-called "pre-fusion") in providing fusion between viral and host cell membranes. Modified viral surface proteins that are based on these features induce neutralizing antibodies with activity available against a broad spectrum of circulating strains and make it possible to overcome the difficulties associated with escape/variability of viral antigen.

[Modification of the Spike Protein for Vaccines against Enveloped RNA Viruses].

Most vaccines work by inducing neutralizing antibodies that target the viral envelope. Enveloped RNA viruses have evolved mechanisms for surface glycoproteins to evade host immune responses, which exhibit substantial variability, even among different strains. Natural infection and vaccines using native forms of surface proteins may induce broadly neutralizing antibodies, yet with low and ineffective levels. Class I membrane-fusion proteins of enveloped RNA viruses, HIV-1, influenza A virus, SARS-CoV-2, yield a stable conformation (so-called "pre-fusion") in providing fusion between viral and host cell membranes. Modified viral surface proteins that are based on these features induce neutralizing antibodies with activity available against a broad spectrum of circulating strains and make it possible to overcome the difficulties associated with escape/variability of viral antigen.

[Evolution of pandemic influenza virus A(H1N1)pdm09 in 2009-2016: dynamics of receptor specificity of the first hemagglutinin subunit (HA1).]

INTRODUCTION: The new reassortant of the swine flu virus A(H1N1)pdm09, which emerged in 2009, overcame the species barrier and caused the 2009-2010 pandemic. One of the key points required for the influenza virus to overcome the species barrier and adapt it to humans is its specific binding to the receptors on the epithelium of the human respiratory tract. PURPOSE: Studying the dynamics of changes in receptor specificity (RS) of the HA1 subunit of the hemagglutinin of the influenza A(H1N1)pdm09 virus strains isolated during the period 2009-2016 on the territory of the Russian Federation, and an analysis of the possible impact of these changes on the incidence rates of the population of the Russian Federation of pandemic influenza in certain epidemic seasons. MATERIAL AND METHODS: Standard methods of collecting clinical materials, isolation of influenza viruses, their typing and genome sequencing were used. For the study of RS of influenza A virus (H1N1)pdm09, the method of solid phase sialosidenzyme analysis was used. RESULTS: It is shown that the change in the parameter W3/6 , which characterizes the degree of a2-3 receptor specificity (a2-3-RS) of the influenza virus A(H1N1) pdm09 over a2-6-RS, coincides with the change in the incidence rates of the Russian Federation's pandemic flu in separate epidemic seasons. There is a tendency to increase the affinity of the virus A(H1N1)pdm09 to α2-3 analogs of the sialyl-glycan receptors of the human respiratory tract epithelium - α2-3-sialoglycopolymers (α2-3-SGP), and falls to α2-6-SGP, with the virus showing the greatest affinity for sulfated sialoglycopolymers. DISCUSSION: Screening for RS strains of influenza A (H1N1)pdm09 virus isolated on the territory of the Russian Federation in 2009-2016 revealed a decrease in the affinity of viruses for a2-6-sialosides, especially for 6'SL-SGP, which is probably due to the presence of amino acid substitutions in the 222 and 223 positions of RBS HA1 viruses. Previous studies have shown that the presence of such substitutions correlates with an increase in the virulence of the influenza A virus (H1N1)pdm09 [16, 23]. Probably, the pandemic virus has evolved towards the selection of more virulent pneumotropic variants. CONCLUSION: Monitoring of the receptor specificity of a pandemic influenza virus makes it possible to identify strains with altered RS to the epithelium of the human respiratory tract and an increased ability to transfer from person to person. Change in the period 2009-2016 the W3/6 parameter characterizing the degree of α2-3-RS excess of the influenza A(H1N1)pdm09 virus over α2-6-RS, coincides with the change in the incidence rates of the pandemic influenza population of the Russian Federation in certain epidemic seasons.

[Low-molecular-weight regulators of biogenic polyamine metabolism affect cytokine production and expression of hepatitis С virus proteins in Huh7.5 human hepatocarcinoma cells].

Hepatitis C virus (HCV) induces the expression of the genes of proinflammatory cytokines, the excessive production of which may cause cell death, and contribute to development of liver fibrosis and hepatocarcinoma. The relationship between cytokine production and metabolic disorders in HCV-infected cells remains obscure. The levels of biogenic polyamines, spermine, spermidine, and their precursor putrescine, may be a potential regulator of these processes. The purpose of the present work was to study the effects of the compounds which modulate biogenic polyamines metabolism on cytokine production and HCV proteins expression. Human hepatocarcinoma Huh7.5 cells have been transfected with the plasmids that encode HCV proteins and further incubated with the following low-molecular compounds that affect different stages of polyamine metabolism: (1) difluoromethylornithine (DFMO), the inhibitor of ornithine decarboxylase, the enzyme that catalyzes the biosynthesis of polyamines; (2) N,N'-bis(2,3-butane dienyl)-1,4-diaminobutane (MDL72.527), the inhibitor of proteins involved in polyamine degradation; and (3) synthetic polyamine analog N^(I),N^(II)-diethylnorspermine (DENSpm), an inducer of polyamine degradation enzyme. The intracellular accumulation and secretion of cytokines (IL-6, IL-1ß, TNF-α, and TGF-ß) was assessed by immunocytochemistry and in the immunoenzyme assay, while the cytokine gene expression was studied using reverse transcription and PCR. The effects of the compounds under analysis on the expression of HCV proteins were analyzed using the indirect immunofluorescence with anti-HCV monoclonal antibodies. It has been demonstrated that, in cells transfected with HCV genes, DFMO reduces the production of three out of four tested cytokines, namely, TNF-α and TGF-ß in cells that express HCV core, Е1Е2, NS3, NS5A, and NS5B proteins, and IL-1ß in the cells that express HCV core, Е1Е2, and NS3 proteins. MDL72527 and DENSpm decreased cytokine production to a lesser extent. Incubation with DFMO led to a 28-32% decrease in the number of cells expressing NS5B or NS5A, both of which are key components of the HCV replication complex. The results obtained in the work indicate that a further detailed study of the antiviral activity of DFMO is required in order to assess its potential as an anti-hepatitis C therapeutic agent.

[Effect of Hepatitis C virus proteins on the production of proinflammatory and profibrotic cytokines in Huh7.5 human hepatoma cells].

Hepatitis C virus (HCV) is a widespread dangerous human pathogen. Up to 80% of HCV-infected individuals develop chronic infection, which is often accompanied by liver inflammation and fibrosis and, at terminal stages, liver cirrhosis and cancer. Treatment of patients with end-stage liver disease is often ineffective, and even patients with suppressed HCV replication have higher risk of death as compared with noninfected subjects. Therefore, investigating the mechanisms that underlie HCV pathogenesis and developing treatments for virus-associated liver dysfunction remain an important goal. The effect of individual HCV proteins on the production of proinflammatory and profibrotic cytokines in hepatocellular carcinoma Huh7.5 cells was analyzed in a systematic manner. Cells were transfected with plasmids encoding HCV proteins. Cytokine production and secretion was accessed by immunocytochemistry and ELISA of the culture medium, and transcription of the cytokine genes was assessed using reverse transcription and PCR. HCV proteins proved to differ in effect on cytokine production. Downregulation of interleukin 6 (IL-6) production was observed in cells expressing the HCV core, NS3, and NS5A proteins. Production of transforming growth factor ß1 (TGF-ß1) was lower in cells expressing the core proteins, NS3, or E1/E2 glycoproteins. A pronounced increase in production and secretion of tumor necrosis factor α (TNF-α) was observed in response to expression of the HCV E1/E2 glycoproteins. A higher biosynthesis, but a lower level in the cell culture medium, was detected for interleukin 1ß (IL-1ß) in cells harboring NS4 and IL-6 in cells expressing NS5В. The finding was possibly explained by protein-specific retention and consequent accumulation of the respective cytokines in the cell.

[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).

[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 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.

[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).

[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.

[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.

[The peculiarities of the influenza epidemics in some areas of Russia during 2012-2013 season. The influenza A (H1N1) pdm09 virus domination in European countries].

The peculiarities of the influenza viruses circulation in 2012-2013 are discussed. The results were obtained in 10 cities of Russia, where basic laboratories of the Influenza Ecology and Epidemics Center of on the basis of Ivanovsky Institute of Virology, Ministry of Health of the Russian Federation, are situated. The increasing rate of the ARD morbidity caused by influenza viruses was observed in January-March 2013. The highest indices of the morbidity were detected during 6-7 weeks with the following decreasing rate till threshold levels to week 14. The influenza A (H1N1) pdm09, A (H3N2), and B viruses were the cause of the epidemic, but their activity differed over areas of Russia. The results of study of the antigenic and genetic properties of the influenza strains demonstrated closed relatives with respect to vaccine strains. In addition, some heterogeneity of the circulating strains and their drift variants were found as well. All tested strains were sensitive to oseltamivir (excluding one A (H1N1) pdm09 strain), zanamivir, arbidol, and remained resistant to rimantadine. The ratio of the ARD viruses was comparable with the last epidemic seasons.

[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).

[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 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.

[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.

[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.

[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.