[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.

[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.

[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.

[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.

[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.

[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.

[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.

[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.

[Cultivation of Mycobacterium tuberculosis in cell culture]. / Metod kul'tivirovaniia mikobakterii tuberkuleza na osnove perevivaemoi kul'tury kletok.

The method of the cultivation of M .tuberculosis in cell subcultures was tested. Five consecutive passages of 2 M. tuberculosis strains were carried out with similar inoculation and cultivation conditions. Mycobacterial cells preserved their morphological characteristics in the course of all passages. The method of M. tuberculosis cultivation in subcultured cells made it possible to study of the physiology of M. tuberculosis under conditions, most approximated to the natural tuberculosis infection in humans.

[The role of the actin cytoskeleton in cell transition through the middle of the G1 phase of the mitotic cycle]. / Rol' aktinovogo tsitoskeleta v prokhozhdenii kletkami serediny fazy G1 mitoticheskogo tsikla.

The influence of dihydrocylochalasin B (H2CB), which selectively disrupts the actin cytoskeleton structure, on G1 phase progression after stimulation of quiescent Swiss 3T3 cells by epidermal growth factor (EGF) was investigated. H2CB was added to the culture medium (10 mg/ml) for different periods of time after cell cycle induction by EGF (10 ng/ml). Efficiency of mitogenic stimulation was estimated by 14C-thymidine uptake 21-23 h after EGF addition. It is shown that the main actin-mediated step is in the middle of G1, from 8 to 12 h after stimulation. Disorganization of actin cytoskeleton structure only during this time led to complete and irreversible block of cell entry into the S phase. On the contrary, the same effect of H2CB during the early period of G1 (first 6 h) led to the increase in 14C-thymidine incorporation in DNA. The specificity of actin-dependent period was proven in experiments with another inhibitor of cell proliferation--dancylcadaverine, whose effect was revealed at the earlier time--4-6 h after cell stimulation. Inhibition of protein synthesis during actin-dependent period (8-12 h) led to the same block of cell progression through G1 as it was seen after actin structure disruption. These data suggest that actin-dependent block is associated with the appearance and functioning of such specific regulators of G1 as cyclins (D, E) and their complexes with Cdk's (G1 kinases) which phosphorylate Rb protein (p1 10) associated with transcription factors E2F.