Water-Soluble Polyoxometal Clusters of Molybdenum (V) with Pyrazole and Triazole: Synthesis and Study of Cytotoxicity and Antiviral Activity

Among well-studied and actively developing compounds are polyoxometalates (POMs), which show application in many fields. Extending this class of compounds, we introduce a new subclass of polyoxometal clusters (POMCs) [Mo12O28(μ-L)8]4- (L = pyrazolate (pz) or triazolate (1,2,3-trz or 1,2,4-trz)), structurally similar to POM, but containing binuclear Mo2O4 clusters linked by bridging oxo- and organic ligands. The complexes obtained by ampoule synthesis from the binuclear cluster [Mo2O4(C2O4)2(H2O)2]2- in a melt of an organic ligand are soluble and stable in aqueous solutions. In addition to the detailed characterization in solid state and in aqueous solution, the biological properties of the compounds on normal and cancer cells were investigated, and antiviral activity against influenza A virus (subtype H5N1) was demonstrated.

Development of a Purified Viral Preparation for Studies of COVID-19 (SARS-CoV-2) Biology

Different methods for producing bulk quantities of concentrated and purified SARS-CoV-2 for the use as antigens and for the research into COVID-19 biology were tested.

Low incidence of human coronavirus among hospitalized children in Novosibirsk city, Russia during pre-pandemic period (2013-2020)

We investigated the incidence of 15 respiratory viruses among 2991 children with acute respiratory infections in Novosibirsk city, Russia, prior to the COVID-19 pandemic (2013-2020). Viral infections were detected in 72.5% cases. The incidence of human coronavirus was 2% (Alphacoronaviruses, 63%; Betacoronaviruses, 37%).

Death Mechanisms of Pulmonary Alveolocytes in Mice Infected with Influenza Viruses A/H1N1/California/04/2009 and A/H5N1/Goose/Krasnoozerskoye/627/05

In CBA mice infected with influenza viruses A/H1N1/California/04/2009 and A/H5N1/Goose/Krasnoozerskoye/627/05 in a dose of 10 MLD₅₀, the mechanisms of death of pulmonary alveolocytes over 10 postinfection days were studied by light microscopy, immunohistochemistry, and morphometry. In mice infected with A/H1N1, alveolocytes died predominantly via necrosis, while apoptosis mostly employed the mitochondrial pathway. In mice infected with A/H5N1, apoptosis was the dominant mechanism of alveolocyte death proceeded via membrane receptor signaling followed by switching to FAS-mediated pathway via activation of FADD, the apoptotic signal transduction protein.

Changes in the Structure of Mouse Kidney in the Acute Period after Infection with Influenza Viruses A/H5N1 and A/H1N1

Changes in the kidney structure in outbred and inbred male BALB/c mice were analyzed in the acute period after infection with influenza viruses A/H5N1 (10 MLD₅₀; 10 days) and A/H1N1 (1 MLD₅₀; 30 days). Antibodies to influenza viruses of both strains were most often expressed by endothelial cells of the glomeruli and arterioles and were rarely expressed by mesangiocytes and tubule epithelial cells. In the kidney, destructive processes induced by viruses and by ischemia due to massive blood vessel thrombosis. Mesangiocytes expressed factors, indicating that they could be qualified as M1 and M2 macrophages. Kidney destruction was more significant after infection of mice with the A/H5N1 virus, but in both experiments cell infiltrates were actually absent, probably due to blood vessel thrombosis and limited possibility of migration of mononuclear phagocytes and lymphocytes to the kidney.

Study of Antiviral Efficiency of Oxidized Dextrans In Vitro and In Vivo

Antiviral efficiency of oxidized dextrans (OD) with different molecular weights and oxidation degree (OD40min, OD70min, OD40max, and OD70 max) was studied in vitro and in vivo. Dextrans OD40max and OD70max prevented the development of the cytopathic effect of influenza A(H1N1)pdm09 virus in more than 50% MDCK cells vs. control (no OD). Four intranasal doses of OD40min, OD40max, and OD70min and one intranasal dose of OD70max before infection of BALB/c mice with A(H1N1)pdm09 influenza virus significantly reduced mortality and prolonged life span in comparison with controls receiving saline. These and our previous data attest to clear-cut preventive effect of OD in influenza infection.

Serological Detection of Causative Agents of Infectious and Invasive Diseases in the Beluga Whale Delphinapterus leucas (Pallas, 1776) (Cetacea: Monodontidae) from Sakhalinsky Bay

Serological detection of some pathogens in the beluga whale Delphinapterus leucas population from Sakhalinsky Bay of the Sea of Okhotsk (Sakhalin-Amur beluga whale stock) was performed in 2013-2014 after the largest recorded flood of the Amur River (among observations since 1896). The percent of this population that is immune to the causative agents of clonorchosis was 25.6%; toxoplasmosis, 11.5%; brucellosis, 38.5%; tuberculosis, 30.8%; cetacean morbillivirus infection, 16.7%; and to alpha and gamma herpes viruses each, 21.8%.

Pathogenicity assessment of wild-type and mouse-adapted influenza A(H1N1) pdm09 viruses in comparison with highly pathogenic influenza A(H5N1) virus

Here we compare the results of pathological and virological examinations of mice experimentally infected with either wild-type or mouse-adapted pandemic A(H1N1) pdm09 viruses and highly pathogenic avian influenza (HPAI) virus A(H5N1). Mice were sacrificed on days 1, 3, 6, and 10 post infection or whenever morbidity was severe enough to justify euthanasia. Morbidity rates were calculated on the basis of clinical signs (weight loss, poor hair coat, hunched posture and paresis); virus-induced disease was characterised by the histopathology of lung; virus dissemination was determined by virus isolation on organ samples of lung, brain, liver, kidney and spleen. All mice infected with mouse-adapted A(H1N1) pdm09 died in the course of the experiment, whereas 20% of animals survived the infection with A(H5N1). Echinocyte formation changed the rheological properties of blood in animals infected with either mouse-adapted A(H1N1) pdm09 or A(H5N1). To sum up, the adaptation of pandemic A(H1N1) pdm09 virus can confer an enhanced virulence similar to or even exceeding that of HPAI A(H5N1) virus.

Evolution of influ- 245 enza A/H5N1 virus (1996-2016)

Twenty years ago in the South Chinese province of Guangdong the epizooty of highly pathogenic avian influenza (HPAI) H5N1 virus, which has laid the foundation of the largest epizooty in the contemporary history, has flashed. Hemagglutinin of prototype A/goose/Guangdong/1/1996 (H5N1) changing many times and generating new genetic subgroups participated in various reassortations; it still exists today. The present review is devoted to the retrospective analysis of HPAI/H5N1evolution for the last twenty years in the territory of Eurasia, Africa and America. The basis for the discussion is ecological model according to which new genetic variants are formed in the migration pathways with close contacts between different bird populations and in the overwintering areas where the maximum values of the immune layer occur; amplification of virus variants occurs in nesting areas among juvenile populations. The updated system of designations of genetic groups introduced by WHO/OIE/FAO H5 Evolution Working Group in 2015 is used.

Experimental infection and pathology of clade 2.2 H5N1 virus in gulls

During 2006, H5N1 HPAI caused an epizootic in wild birds, resulting in a die-off of Laridae in the Novosibirsk region at Chany Lake. In the present study, we infected common gulls (Larus canus) with a high dose of the H5N1 HPAI virus isolated from a common gull to determine if severe disease could be induced over the 28 day experimental period. Moderate clinical signs including diarrhea, conjunctivitis, respiratory distress and neurological signs were observed in virus-inoculated birds, and 50% died. The most common microscopic lesions observed were necrosis of the pancreas, mild encephalitis, mild myocarditis, liver parenchymal hemorrhages, lymphocytic hepatitis, parabronchi lumen hemorrhages and interstitial pneumonia. High viral titers were shed from the oropharyngeal route and virus was still detected in one bird at 25 days after infection. In the cloaca, the virus was detected sporadically in lower titers. The virus was transmitted to direct contact gulls. Thus, infected gulls can pose a significant risk of H5N1 HPAIV transmission to other wild migratory waterfowl and pose a risk to more susceptible poultry species. These findings have important implications regarding the mode of transmission and potential risks of H5N1 HPAI spread by gulls.

Studies of Influenza A/H1N1 A/Tomsk/13/2010 Virus Topology during Development of Infectious Process in Mammals

Influenza A/H1N1 A/Tomsk/13/2010 virus registered in Siberia in 2010 proved to be an extremely pathogenic strain. Dynamic study of the topology of this influenza virus strain in the lungs, liver, kidneys, lymph nodes, and great vessels of infected mice was carried out. Influenza A virus was detected by immunohistochemical methods in cells of different histogenesis in all the studied organs throughout the observation period (days 1-30 postinfection), which indicated effective replication and long persistence of influenza A/H1N1 A/Tomsk/13/2010 virus in mammalian cells.

Adaptation of influenza A(H1N1)pdm09 virus in experimental mouse models

In the present study, three mouse-adapted variants of influenza A(H1N1)pdm09 virus were obtained by lung-to-lung passages of BALB/c, C57BL/6z and CD1 mice. The significantly increased virulence and pathogenicity of all of the mouse-adapted variants induced 100% mortality in the adapted mice. Genetic analysis indicated that the increased virulence of all of the mouse-adapted variants reflected the incremental acquisition of several mutations in PB2, PB1, HA, NP, NA, and NS2 proteins. Identical amino acid substitutions were also detected in all of the mouse-adapted variants of A(H1N1)pdm09 virus, including PB2 (K251R), PB1 (V652A), NP (I353V), NA (I106V, N248D) and NS1 (G159E). Apparently, influenza A(H1N1)pdm09 virus easily adapted to the host after serial passages in the lungs, inducing 100% lethality in the last experimental group. However, cross-challenge revealed that not all adapted variants are pathogenic for different laboratory mice. Such important results should be considered when using the influenza mice model.

Biological characteristics of influenza A(H1N1)pdm09 virus circulating in West Siberia during pandemic and post-pandemic periods

We studied biological characteristics of influenza A(H1N1)pdm09 virus circulating in Siberia during the 2009 pandemic and the post-pandemic period of 2011. BALB/c mice were chosen as the experimental model. Virus titers in the lungs were evaluated on days 1, 3, 6 and blood serum titers on day 15 after infection with different strains. Blood sera of convalescents after influenza of 2010-2011 epidemic season were analyzed. Influenza A(H1N1)pdm09 virus strains isolated during the post-pandemic period of 2011 were characterized by low epidemic activity and virulence in comparison with the strains isolated during 2009 pandemic period, which indicates completion of the pandemic cycle.

Role of matrix metalloproteinases and their inhibitor in the development of early pulmonary fibrosis in mice infected with influenza A/H5N1 A/goose/Krasnoozerskoye/627/05 virus

High levels of macrophages and fibroblasts expressing MMP-2, MMP-9, and MMP-10 against the background of progressing early fibrosis of the lungs (manifesting in an increase in volume density of type I, III, IV, and VI collagens) were found in C57Bl/6 mice infected with influenza A/H5N1 A/goose/Krasnoozerskoye/627/05 virus. Progressing fibrosis of the lungs in infected mice was associated with imbalance of collagen synthesis and degradation processes conjugated with high levels of macrophages and fibroblasts expressing TIMP-2.

Structural and functional changes in pulmonary macrophages and lungs of mice infected with influenza virus A/H5N1 A/goose/Krasnoozerskoye/627/05

C57Bl/6 mice were intranasally infected with influenza virus A/H5N1 A/goose/Krasnoozerskoye/627/05. The mortality rate of animals reached 70% on day 14 of the disease. The lungs of animals were characterized by necroses, destruction of vessels, hemorrhagic and thrombotic complications, edematous syndrome, and early fibrosis of the interstitium. On days 6-10 after infection, fibrosis was found in the zones of postnecrotic inflammatory infiltration. The expression of lysozyme and myeloperoxidase by pulmonary macrophages was initially increased, but decreased on day 10 of the study. The number of cathepsin D-expressing macrophages was elevated up to the 10th day of examination.

[Genetic variants of the Crimean-Congo hemorrhagic fever virus circulating in endemic areas of the southern Tajikistan in 2009]

506 Hyalomma anatolicum ticks were collected and assayed in two Crimean-Congo hemorrhagic fever (CCHF) endemic regions of Tajikistan. Antigen and RNA of CCHF virus were detected in 3.4% of tick pools from Rudaki district using ELISA and RT-PCR tests. As of Tursunzade district, viral antigen was identified in 9.0% of samples and viral RNA was identified in 8.1% of samples. The multiple alignment of the obtained nucleotide sequences of CCHF virus genome S-segment 287-nt region (996-1282) and multiple alignment of deduced amino acid sequences of the samples, carried out to compare with CCHF virus strains from the GenBank database, as well as phylogenetic analysis, enabled us to conclude that Asia 1 and Asia 2 genotypes of CCHF virus are circulating in Tajikistan. It is important to note that the genotype Asia 1 virus was detected for the first time in Tajikistan.

[Biological properties of velogenic strains of the Newcastle disease virus isolated in the Northern Caucasian region]

The results of the biological property investigation of two Newcastle virus strains isolated in Northern Caucasian region--NDV/Adigeya/duck/8/2008 and NDV/Adigeya/duck/15/2008--were presented. The phylogenetic analysis revealed that these strains belonged to genotype 7 of clade 2. Using molecular-biological analysis of established nucleotide sequences including proteolytic site of fusion peptide it was demonstrated that the strains were velogenic. This conclusion was proved by testing the pathogenicity on the model of intracerebral infected chickens (ICPI--IntraCerebral Pathogenic Index--was found to be 2). Pathomorphological study of dead chickens made it possible to classify strains as neurotropic with low level of visceral tropism.

Surveillance of influenza A virus in wild birds in the Asian portion of Russia in 2008

Wild waterfowl undertake a variety of long-distance flights during their migration. These flights provide birds with the opportunities to both acquire and disseminate avian influenza viruses (AIVs). The Asian portion of Russia is crossed by four major migration routes and represents the major breeding area for many wild bird species in the Palearctic. The Asian territory of Russia plays an important role in distribution, persistence, and evolution of AIVs due to the ecologic relationships of bird populations from Russia and different Asian, European, African, and North American countries. Our study highlights the results of surveillance conducted in 2008 for AIVs in wild birds in the Asian portion of Russia. During this study, our team collected and tested 5678 samples from wild birds. Among them, 41 samples tested positive for AIV with an isolation rate of 0.72%. The highest AIV prevalence, 1.49%, was found in Anseriformes. In Ardeidae and Laridae, the AIV prevalence was 1.23% and 0.64%, respectively. Rallidae showed the lowest AIV prevalence of 0.61%. Phylogenetic analysis of H3 and H4 subtypes represented close relationships of AIVs isolated from the Asian portion of Russia to the AI strains from Asia, Africa, and Europe. These findings were confirmed by the wild bird migration routes that affect bird populations from Eurasian, African, Australian, and North American continents.

[Experimental infection caused by influenza A (H5N1) virus in common gull (Larus canus)]

The influenza A/common gull/Chany/P/2006 (HSN1) virus strain Isolated from a clinically healthy common gull (Larus canus) caused no death of Its natural host (a common gull). The virus was shown to be capable for effective replication in the tissues of the lung, spleen, and upper respiratory tract and in the intestinal mucosal cells of the common gull with further environmental virus liberation elimination along with mucinous discharges from the cloaca and fauces for 2 weeks. The potential role of this bird species in the circulation of influenza virus is discussed.

Ecology of influenza virus in wild bird populations in Central Asia

The study provides the results of avian influenza virus surveillance in Central Asia during 2003-2009. We have analyzed 2604 samples from wild birds. These samples were collected in Kazakhstan (279), Mongolia (650), and Russia (1675). Isolated viruses from samples collected in Mongolia (13 isolates) and in Russia (4 isolates) were described. Virological analysis has shown that six isolates belong to the H3N6 subtype and five isolates belong to the H4N6 subtype. Two H1N1 influenza viruses, one H10N7 virus, two H3N8 viruses, and an H13N8 virus that is new for Central Asia have been also isolated. Samples were taken from birds of six orders, including several species preferring water and semiaquatic biotopes, one species preferring dry plain regions, and one more species that can inhabit both dry and water biotopes.

[Molecular-biological and antigenic features of H5N1 subtype highly pathogenic influenza virus strains isolated in southern Siberia in 2005-2009]

AIM

Study of molecular-biological and antigenic features of H5N1 subtype virus strains isolated in southern Siberia in 2005-2009.

MATERIALS AND METHODS

Study was performed by using standard procedures according to WHO recommendations.

RESULTS

Hemagglutinin gene of H5N1 subtype virus strain isolated in Siberia belongs to 2 genetical lineages: 2.2 and 2.3.2. Strains of these 2 lineages have antigenic differences. All of the strains are highly pathogenic for chicken and white mice.

CONCLUSION

H5N1 subtype highly pathogenic influenza virus variants of 2 different antigenic lineages that have antigenic differences circulated in Siberia in 2005-2009. A possible role of antigenic drift in evolution of H5N1 subtype influenza virus is discussed.

[Genetical features of influenza virus A (H1N1) strain that caused the 2009 pandemic]

Genetical features of the A(H1N1) influenza virus strain that caused the 2009 pandemic are analyzed in the review. Mutations typical for this strain, unique and similar to influenza viruses of swine, avian and seasonal types, and phenotypic (pathologic) features associated with them, that are experimentally confirmed, are described. A possibility of reassortation of avian and swine influenza viruses and possible epidemiologic consequences are discussed.

[Studies of properties of pandemic influenza virus A/H1N1 circulated in Russian Federation in 2009 - 2010]

AIM

Studies of cultural, virologic, antigenic properties of 89 samples of pandemic influenza A(H1N1) 2009 virus isolated in Russian Federation from May 2009 to March 2010.

MATERIALS AND METHODS

Properties of isolated samples were compared with those of the reference strain A/ California/04/2009 (H1N1).

RESULTS

Studies of biological properties and analysis of genome nucleotide sequences of the isolated samples showed that those strains are closely related to the reference strain.

CONCLUSION

Monitoring of genetic, virologic and antigenic properties of pandemic influenza A(H1N1) 2009 virus isolates carried out from May 2009 to March 2010 did not reveal significant changes in the abovementioned properties of the virus or emergence of mutations that can lead to such changes.

[Characterization of the H5N1 influenza virus isolated during an outbreak among wild birds in Russia (Tuva Republic) in 2010]

The study of basic biological properties of H5N1 subtype strain isolated during an outbreak among wild birds in Russia in 2010 was presented. The study was carried out using conventional methods according to the WHO recommendations. H5N1 influenza virus isolated in Siberia belonged to clade 2.3.2 of the hemagglutinin gene; the phylogenetic analysis was performed. The antigenic characteristics and the basic genetic markers of biological properties were studied. It was shown that all strains were highly pathogenic for chickens and white mice. Thus, it was shown that in Russia in the 2010 H5N1 virus phylogenetically closely related to Asian variants caused epizootic among wild birds. The potential danger of this variant of the virus for humans was confirmed by different methods. We discussed the possibility of formation of H5N1 influenza natural focus.

[Pandemic influenza virus A (H1N1) in Amur region in autumn 2009]

AIM

Isolation and study of molecular genetic characteristics of pandemic influenza virus A (H1N1) circulated in Amur region in autumn 2009 as well as testing of serum samples taken from citizens of this region during November- December 2009 in order to measure levels of antibodies to socially significant serotypes of influenza A virus.

MATERIALS AND METHODS

Strain of pandemic influenza virus A/Blagoveschensk/01/2009 (H1N1) was isolated on MDCK cell culture and nucleotide sequences of all eight segments of viral genome were determined. Five hundred seventy-six serum samples taken in Amur region in autumn 2009 were tested by hemagglutination inhibition assay.

RESULTS

Nucleotide sequence of A/Blagovechensk/01/2009 (H1N1) strain was 99.7% identical to reference influenza virus strain A/California/04/2009. Diagnostically significant titers of antibodies to pandemic influenza virus were observed in 46.3% of persons younger 30 years old and in 20.1% older persons. Antibodies to seasonal influenza virus H1N1 and H3N2 were detected in 39.5 and 29.8% of persons respectively.

CONCLUSION

Final seroepidemiological picture of distribution of pandemic virus in Amur region matches with the one for seasonal influenza virus A (H1N1): > 60% of seropositive persons were registered in age group < 18 years old, and this proportion increases with increasing age.

[Monitoring for influenza in population of Western Siberia in 2007-2009]

AIM

To analyze influenza viruses isolated in the 2008-2009 autumn-winter season, and to test sera collected in the south of Western Siberia during the beginning and the end of the epidemic seasons from 2007 until the A/H1N1 pandemic.

MATERIALS AND METHODS

Total 149 clinical samples were analyzed and 2190 blood sera were tested. During the 2008-2009 season 17 influenza viruses were isolated. 9 of these were A/H1N1, 5-were A/H3N2, and 3 were influenza B viruses. The nucleotide sequences and amino acid composition of influenza A virus hemagglutinin (HA) were compared with reference strains.

RESULTS

Among A/H1N1 viruses circulating in Novosibirsk region three viruses contained four amino acid replacements in antigen sites Ca, Cb and Sb. In A/ H3N2 viruses from Novosibirsk, 2 amino acid substitutions were detected in antigen sites B and E.

CONCLUSION

Based on genotyping influenzae epidemic on February to April of 2009 in the south of western Siberia was associated with influenza viruses A/H1N1, A/H3N2, and B. All A/H3N2 influenza virus isolates were variants of reference A/Brisbane/10/2007(H3N2) and A/ H1N1 influenza viruses isolates were similar to reference A/Brisbane/59/2007(H1N1).

[Isolation of influenza A virus from wild birds in western part of Mongolia]

AIM

To study circulation of influenza A viruses in western part of Mongolia.

MATERIALS AND METHODS

Isolation and characterization of influenza viruses was performed according to recommendations of WHO.

RESULTS

Circulation of influenza A viruses subtypes H3N6, H4N6, H1N1, H13N8 in different wild bird species in western part of Mongolia was documented.

CONCLUSION

Taxonomic and ecologic heterogeneity of bird species involved in continuous circulation of influenza A viruses was revealed. Subtype H13N8 was isolated for a first time from herring gull on territory of western Mongolia.

[Study of the antiviral activity of Russian anti-influenza agents in cell culture and animal models]

The study of the antiviral activity of Russian anti-influenza agents in the cultured MDCK cells demonstrated that arbidol and ribavirin inhibited the reproduction of various influenza A virus strains, including rimantadine- and ozeltamivir-resistant variants, as well as influenza B viruses (IC50 2-8.5 microg/ml). Rimantadine at concentrations of 1-5 microg/ml completely inhibited the reproduction of reference and ozeltamivir-resistant influenza A virus strains, and it had no effect on the reproduction of influenza B viruses and rimantadine-resistant influenza A viruses. Arbidol and ribavirin also inhibited the reproduction of pandemic influenza A/California/04/2009(H1N1), A/California/07/2009(H1N1), and A/Moscow/01/2009(H1N1)swl viruses in the cultured MDCK cells (IC50 = 1.5-4.0 microg/ml) while rimantadine had no effect on their reproduction. The cultured cells showed no significant antiviral activity of ingavirin at nontoxic concentrations (up to 200 microg/ml) against all study strains of influenza A and B viruses, including pandemic A(H1N1) influenza virus strains. The activity of rimantadine, arbidol, and ingavirin was found on a model of Influenza pneumonia in mice infected with their adopted influenza A/Aichi/2/69(H3N2) virus. The preventive efficacy of the three test agents was similar and most pronounced when they were used 96 hours before infection, by preventing 40-50% death in the animals and their body weight loss and by increasing their survival by 1.3-1.5 times. Arbidol and rimantadine were more effective when used for treatment and prophylaxis in doses of 30 and 10 mg/kg/day, respectively, by protecting the infected animals from 60-80% death, increasing their survival by 1.7-2 times, and preventing their body weight loss as compared with the control. The same experiments with ingavirin showed that this agent was less effective than arbidol and rimantadine. Thus, arbidol and rimantadine have a pronounced antiviral infection in both cell culture and a model of influenza pneumonia. The found efficacy of ingavirin on an integral model of murine influenza pneumonia without its activity in the cultured cells is likely to be due to other pharmacological properties of the drug rather than its direct virus-specific action.

[Detection of antibodies to A/H5N1 influenza virus in citizens of Russian Federation]

AIM

To determine levels of antibodies to influenza virus A/H5N1 in serum samples of people living in different regions of Russia in order to assess the risk of infection with avian influenza H5N1.

MATERIALS AND METHODS

Two thousand one hundred sixty-eight serum samples were tested by hemagglutination inhibition assay for the presence of antibodies to influenza virus A/H5N1.

RESULTS

Twenty-six serum samples obtained from residents of Khanty-Mansiysk Autonomous Area and 2 samples from residents of Novosibirsk region were positive for antibodies to serotype A/H5. There were no clinical cases of avain influenza A/H5N1 infection in medical history of studied persons.

CONCLUSION

Since cases of asymptomatic carriage of A/H5N1 influenza virus in water birds are described and ability of the virus to survive in water environment for a long time is shown, it seems logical to detect antibodies to influenza virus A/H5 in sera of subjects living in Russian Federation taking into account that influenza virus A/H5N1 is isolated from wild fowl and poultry since 2005.

[Characteristic of high pathogenic avian influenza virus subtype H5N1 isolated from common gull (Larus canus)]

AIM

To study biological characteristics of H5N1 influenza virus isolated from common gull on south of West Siberia in 2006.

MATERIALS AND METHODS

Isolation and characterization of biological characteristics performed according to recommendations of World Health Organization.

RESULTS

Influenza virus A (H5N1) was first isolated from common gull (Larus canus) in Russia. Antigen of isolated virus had significant affinity to polyclonal sera obtained against high pathogenic avian influenza viruses H5N1 circulating in South-East Asia. Phylogenetic analysis of isolated strain revealed its belonging to group of Qinghai-related variants of H5N1 influenza virus. Aminoacid structure of hemagglutinin proteolytic cleavage site is characteristic for type A high pathogenicity avian influenza viruses. Experimental infection of chickens demonstrated high pathogenicity of the isolated virus.

CONCLUSION

Involvement of common gulls in circulation of subtype H5N1 influenza virus is demonstrated for the first time. Important role of species from Laridae family in unprecedented spreading of H5N1 influenza virus started in 2005 is discussed.

[Hemagglutination inhibition test for retrospective diagnosis of avian influenza in mammals]

AIM

To compare usage of native and formalinized erythrocytes from different animal species in hemagglutination inhibition (HI) test for detection of level of specific antibodies to H5N1 influenza virus in sera of mammals.

MATERIALS AND METHODS

Level of anti-H5 antibodies to influenza H5 control antigen and to influenza viruses A/Common gull/Chany/2006 (H5N1), A/duck/Tuva/01/06 (H5N1), A/Anas platyrhynchos/Chany Lake/9/03 (H5N3) was determined by hemagglutination inhibition test in two influenza A (H5) reference antisera as well as in ferret antisera to native strains of avian influenza virus. Equine, rhesus macaque, sheep, guinea pig, goose, and chicken erythrocytes were used.

RESULTS

Using reference antisera, H5 hemagglutinin was detected in all tested antigens with all used erythrocytes. While testing ferret antisera in HI test with reference antigen, anti-H5 antibodies were not detected or detected in extremely low titre (1/80) and only with equine erythrocytes. In most cases, titers of anti-H5 antibodies in HI test with formalinized erythrocytes were higher than with native ones.

CONCLUSION

During monitoring for antibodies to H5N1 avian influenza virus in human population it is necessary to use native strains of A/H5N1 along with reference antigen. It is possible to use formalinized equine, rhesus macaque, goose, and chicken erythrocytes.

Pathogenesis of infectious disease of mice caused by H5N1 avian influenza virus

The pathogenesis of a disease caused by Qinghai-like H5N1 influenza virus in BALB/c mice was studied. Clinical, morphological, and immunological characteristics of the experimental infection caused by highly pathogenic A/duck/Tuva/01/06/ (H5N1) virus are described.

[Monitoring of antibodies to influenza A virus in populations of different regions of West Siberia]

AIM

To study levels of antibodies to influenza virus in sera of subjects residing in different regions of West Siberia in order to assess the risk of infection with avian influenza virus H5N1.

MATERIALS AND METHODS

Two hundred and sixty-five serum samples were tested for the presence of antibodies to influenza virus A/New Caledonia/99 (H1N1), A/New York/55/2005 (H3N2), A/Whooper swan/ Mongolia/244/2005 (H5N1) by hemagglutination inhibition assay (HAI) and reaction of microneutralization.

RESULTS

All tested sera were negative for antibodies to H5N1. 14.2% and 44.1% of sera were positive for antibodies to H1N1 in HAI and reaction of microneutralization respectively. In respect of antibodies to H3N2 virus, the proportion of positive sera was higher--40.3% and 76.2%, respectively.

CONCLUSION

Results of such studies are very actual, especially during pandemic threat. Furthermore, such information allows to better predict consequences of seasonal influenza epidemics caused by serotypes circulating at the present time.

[Investigation of susceptibility of influenza viruses A (H1N1), the cause of infection in humans in April-May 2009, to antivirals in MDCK cell culture]

Biological properties of influenza viruses A (H1N1), that were the cause of the infection in humans in April - May 2009, and the action of the Russian antivirals on their reproduction were studied in vitro. The nucleotide sequence in the viruses was determined and followed by detection of the mutations responsible for resistance to the antiinfluenza drugs. The experiments showned that arbidol and ribavirin had a selective inhibitory action on reproduction of the viruses in the MDCK cell culture while rimantadine had no affect on their reproduction. The data were confirmed by the results of the genome analysis in influenza viruses A/California/04/2009(H1N1), A/California/07/2009(H1N1) and A/Moscow/01/2009(H1N1)swl, that revealed no replacements defining the resistance to arbidol while the viruses contained a mutation in position 31 of M2 protein, responsible for the resistance to adamantans.

[Isolation and molecular characterization of the influenza virus A/H5N1 strains isolated during outbreak of avian influenza among birds in the European part of Russia in 2005: strain with ozeltamivir-resistance mutation was found]

Isolation and characterization of the influenza virus A/H5N1 strains, isolated from chicken in the Yandovka village (Tula Region) and from wild swan near the orifice of the Volga River that died during an outbreak of avian flu in autumn 2005, were carried out. Genetic and phylogenetic analyses were performed. The goals of the analysis were to determine possible geographical origin of the strain, genetic similarity of isolated strains to earlier sequenced isolates, epidemic potential, existence of pathogenicity markers, and resistance to antiviral drugs. It was shown that the isolated influenza virus belonged to highly pathogenic variants of China origin by a reassortment of viruses genotypes Z and V circulated in poultry and wild birds. A number of molecular markers of pathogenicity to gallinaceous birds and mammals were found out. Mutations in the hemagglutinin gene promoting potentially high rate of replication in humans as well as mutations causing the resistance to amantadine/rimantadine were not found. The strain isolated from wild swan had the mutation causing resistance to tamiflu/ozeltamivir.

[Detection of specific antibodies to morbilliviruses, Toxoplasma, and Brucella species in eared seals in North-West of Pacific Ocean]

Presence of antibodies to morbilliviruses, Toxoplasma, and Brucella species in eared seals in North-West of Pacific Ocean was studied. Sera from 189 cubs of eared seals from different rookeries and regions. It has been shown that 10-22% of cubs living on Russian coast have antibodies to such dangerous diseases as morbillivirus infection, brucellosis, and toxoplasmosis. Antibodies to the two pathogens were detected in several animals, and brucellosis was more frequently detected associated infection. These results confirm hypothesis that all 3 pathogens are enzootic in eared seals population.

[Species composition of mosquitoes (Diptera, Culicidae) and possibility of the West Nile virus natural foci formation in the South of Western Siberia]

In 2004 June-July collections of mosquito adults and small mammals were carried out in two areas of Novosibirsk Region (forest-steppe and steppe zones), where the West Nile virus (WNV) was for the first time recorded in birds with different migration status in 2002-2004. Seventeen species of mosquitoes were found; significant changes in their species composition and abundance, as compared with latest faunistic studies made in the sixties-seventies of the last century, are revealed. WNV markers (antigen, RNA) are found in small mammals; highly sensitive to the WNV replication mosquito species are also found. These facts allow supposing a possibility of the formation of stable West Nile virus natural foci in the South of Western Siberia, under conditions of forest-steppe and steppe zones.

[Molecular-biologic analysis of avian influenza virus isolates which caused epizootics on the south of West Siberia and in Crimea]

The objective of the study was to determine reasons of poultry deaths in Crimea Republic in December 2005 as well as isolation, identification, and comparative analysis of pathogens, which caused epizootics in Siberia and Crimea. During epizootic in poultry in North-East Crimea highly pathogenic avian influenza virus H5N1 was isolated. Phylogenetic analysis of RNA sequences revealed that they belong to one big cluster. Isolated strain was close to viruses, which caused epizootic in July-August 2005 in the south of West Siberia. Conclusion about the high importance of the south of West Siberia in spreading of highly pathogenic influenza viruses H5N1 in Eurasia was made.

[Surveillance for avian influenza virus in synanthropic birds during epizootic and postepizootic periods on the south of west Siberia]

Results of virologic examination of synanthropic birds procured on the south part of West Siberia during epizootic in autumn 2005 and during postepizootic period (winter 2005-2006) are presented. During epizootic period one strain belonging to H4 subtype of hemagglutinin, which was not highly pathogenic, was isolated from a magpie. During postepizootic period influenza A viruses in synanthropic species were not found.

[Cases of West Nile fever in Novosibirsk region in 2004, and the genotyping of its viral pathogen]

Three cases of West Nile fever were registered for the first time in Novosibirsk region in 2004. The diagnosis was confirmed by revealing IgG against West Nile virus (three cases) and viral RNA (two cases). Sequence analysis of fragments of E protein gene showed that the virus belonged to Ia genotype.

[Circulation of type A influenza viruses in poultry during the pre-epizootic period of 2005 in Novosibirsk region]

Work is devoted to studying of circulation of avian flu influenza A (H5N1) virus at poultry in territory of Novosibirsk region in preepizootic period. 1901 sample from clinically healthy poultry is collected and investigated. On chicken embryos it has been isolated 28 virions, including from poultry of the industrial maintenance--16, from the poultry contained in private farmsteads--12. At the analysis of isolates it has been shown, that among poultry in preepizootic period circulated various serovars of influenza viruses namely, HI, H4 and H3 serogroups. The percent of isolates from geese of the industrial maintenance increased to 0.6% depending on area. The percent of isolates from a bird contained in private farmsteads, increased to 7.5%. The greatest percent of isolates was observed from the samples taken from hens--77. Thus, it is shown, that among poultry circulation of not pathogenic influenza viruses of type A is the usual phenomenon, and asymptomatic carriers 7.5% of a livestock. Also it has been established, that in preepizootic period 2005 (January-June) at poultry it is not revealed influenza viruses of H5 serotype, caused epizootia at Summer of 2005 in territory of Western Siberia.

[Results of two-year-old inspection of the presence of infuenza virus in wild birds in Western Mongolia]

The results of virology inspection of the wild birds living in territory of the Western Mongolia, carried out in 2003-2004 are presented. For the specified period influenza viruses H3 and H4 subtype hemagglutinins are isolated from birds. It is revealed taxonomic and ecological heterogeneity of the birds involved in maintenance of circulation of influenza viruses in the given territory. Influenza viruses are isolated from birds of 5 special groups; among them there are preferring water and nearwater biotops, a species preferring dry plain region, and also a species which habitat does not depend from water's territories.

[Study of highly pathogenic H5N1 influenza virus isolated from sick and dead birds in Western Siberia]

The mass destruction of domestic birds has been registered in July, 2005 in Novosibirsk region. Influenza virus H5N1 have been isolated from bodies of the lost birds on developing chicken embryos and identified by serological and molecular biological methods. M-gene and genes coding hemagglutinin and neurominidase were in part sequening. The phylogenetic analysis of hemagglutinin gene has shown, that the isolated viruses are forming a claster with strains, isolated from birds during outbreak of the bird's flu on lake Tsinghai (Qinghai) in China in 2005, in Japan in 2004, and also with H5N1 strains, isolated from the person and birds in the countries of Southeast Asia during ipizootia in 2003-2004. The site of the restriction which associated with pathogenicity of isolated avian influenza viruses H5 serogroup, corresponds to sequence of high pathogenic strains, circulating in the countries of Southeast Asia. The test for pathogenicity with use of chickens has confirmed, that researched strains were high pathogenic for birds.

[West Nile virus genotyping among wild birds belonging to ground and tree-brush bird populations on the territories of the Baraba forest-steppe and Kulunda steppe (2003-2004)]

The paper gives the results of the 2003-2004 examinations of 104 wild birds belonging to land tree-brush complexes from the Baraba forest-steppe and Kulunda steppe for the detection and genotyping West Nile virus (WNV). ELISA and RT-PCR were used to show that in the forest-steppe and steppe zones of the south of Western Siberia, WNV circulates among both migrating and settled birds. An analysis of the nucleotide sequence of a protein E gene fragment showed the circulation of WNV genotype Ia in the study birds. A number of revealed amino acid substitutions in surface glycoprotein E are unique for the 2003-2004 Western-Siberian WNV variants and absent in the 2002 Western-Siberian variants, which suggests that there are regional features of the evolution of WNV genotype Ia.

[The 2003 results of monitoring of influenza A virus in the populations of wild birds in the south of Western Siberia]

The paper presents the results of isolation of influenza A virus from 97 cloacal swabs of 11 species of aquatic and semiaquatic wild birds collected on the Chany Lake (the south of Western Siberia, Ob-Irtysh interarea). Six strains with subtypes H2 (2 strains), H3 (3 strains), and H5 (1 strain) were isolated from mallard ducks (Anas platyrhynchos). The total infection rate in the examined birds was 6.2% and that in the ducks was 9.7%. The paper deals with the phylogenetic analysis of hemagglutinin of genes of isolates and with the comparison of the obtained results with the 2002 data in the same region. Analysis of H5 strain hemagglutinin proteolytic site permits one to regard this strain as non-pathogenic.

[The genotyping of the West Nile virus in birds in the far eastern region of Russia in 2002-2004]

Samples from 20 species of trapped and dead birds were collected in the Far Eastern Region in 2002-2004 and were analyzed by the anti-WNV MAb-modified immunoenzyme assay for antigen detection and RT-PCR for viral RNA detection. Five positive samples from cinereous vultures (Aegypius monachus) and two positive samples from cattle egret (Bubulcus ibis) were found in both tests. The sequencing of the 322 bp fragments of protein E gene showed 99-99.67% homology with the strain WNV/LEIV-VlgOO-27924 of the WNV isolated in Volgograd, Russia, 2000. Additionally, five positive samples from birds (Pica pica, Corvus macrorhynchos, Larus crossirostris, Parus minor, Emberiza spodocephala) collected in autumn 2004 were found during screening with anti-WNV MAb-modified ELISA. These results confirm that the WNV is circulating in the Far Eastern Region of Russia and outbreaks of WN fever in humans may be possible. This demonstrates that the genotype 1a of the West Nile virus could spread in the southern regions of the Far East by migrating birds and introduction of the WNV into other southern regions of the Asian part of Russia are probably.