[Astroviral infection in Russian Federation].

The astroviral infections are considered among the most common pathogens of gastroenteritis in children. The incidence, molecular epidemiology and clinical manifestations of the astrovirus infection in children hospitalized with acute gastroenteritis, in various areas of the Russian Federation from 2004 to 2010 was determined.

[Molecular characterization of pandemic influenza viruses A/H1N1(sw2009) isolated in Russia in 2009-2010].

AIM: Assessment of genetic diversity of influenza virus A/H1N1 (sw2009) variants circulated in Russia, study of virus' pathogenicity in humans and potential resistance to antiviral drugs. MATERIALS AND METHODS: Sequencing of PCR-fragments of genome of influenza viruses isolated from clinical and autopsy samples of 436 patients. Four full genome sequences of influenza viruses A/H1N1 (sw2009) were obtained. Phylogenetic analysis was performed. RESULTS: High degree of homology (98.9-100%) was found among influenza A/H1N1(sw2009) viruses in HA and NA genes as well as in their aminoacid sequences (1.3 and 1.4% respectively). Differences in other proteins did not exceed 1.1%. Diversity was found in position 222 of receptor-binding locus of HA and single amino acid polymorphism--in several internal proteins. Known mutations determining resistance to Tamiflu and Arbidol were not detected. All viruses were resistant to remantadine. Molecular markers of high pathogenicity were not found. CONCLUSION: High homology of influenza viruses determines low level of antigenic differences although in populations of viruses there are variants with different levels of adaptation to human organism and different affinity to receptors of upper and lower respiratory tract that can determine their different transmissibility.

[Monitoring for Neisseria meningitidis species using sequencing of variable fragments of surface proteins FetA and PorA genes].

AIM: To perform advanced antigenic characterization of meningococci belonging to serogroups A and B and circulating in Moscow according to modern nomenclature of Neisseria meningitidis strains. MATERIALS AND METHODS: Method of typing of "VR" fragment of FetA protein together with methods of genetic subtyping and multilocus sequence typing was used. RESULTS: Detailed information about studied strains was inputed in Internet database--http://pubmlst.org/neisseria/. Typing of serogroup B strains did not allow to define dominating variant of "VR, fragment of FetA protein which is in accordance with subtyping data obtained previously. Serogroup A strains were notable for less variability of "VR" fragment variants: 6 variants were detected. For the majority of serogroup A strains, it was possible to trace connection between belonging of the strain to particular genetic subgroup and its revealed antigenic profile. For strains from genetic subgroup VI, antigenic profile P1.5-2, 10; F1-5 detected in 14(18%) strains was typical, whereas antigenic profile P1.5-2, 10; F3-5 was typical for genetic subgroup X and was detected in 50 (63%) strains. Antigenic profile P1.5-2, 10-67; F3-5 was detected in 5 (6%) strains, and other 10 antigenic profiles were revealed in one strain each. CONCLUSION: Prevalence of strains with antigenic profile P1.5-2, 10; F3-5 is explained by change of predominant genetic subgroup from subgroup VI to subgroup X in Moscow population serogroup A meningococci observed after 2003.

[Design of an immunochip for separate detection of hepatitis C virus antibodies].

A test kit as an immunochip designed for the diagnosis of hepatic C virus (HCV) has a high sensitivity and specificity. Recombinant HCV antigens were separately immobilized on the activated slides together with internal controls. Serum test results were red by ScanArray Express. K-factor and corresponding value of cut-off were calculated for each antigen and internal controls. Comparative evaluation of the sensitivity and specificity of the immunochip was carried out by commercial ELISA test kits and linear blotting analyses on 448 blood samples containing and free from NCV antibodies.

[Application of molecular genetic methods during Legionnaires' disease outbreak in town Verkhnyaya Pyshma].

The aim of the study was to perform molecular genetic analysis based on multi-locus sequence typing in order to identify source of Legionnaires' disease outbreak in town Verkhnyaya Pyshma in July 2007 and genetic profile of the causative agent. Sequence-based typing protocol recommended by European Working Group on Legionella infection (EWGLI) was used. It was not possible to obtain satisfactory results of Fla gene sequencing for all samples. Obtained allelic profiles of other genes were typical for L. pneumophila. Allelic profiles of L. pneumophila isolated from patients were identical and matched with L. pneumophila DNA detected in water from hot water supply of domestic building, but differed from cooling tower's isolates and isolates from showerhead in apartment of one patient. Identity of 5 genes of L. pneumophila isolated from autopsy samples and from hot water of central hot water supply of domestic building confirms aspiration route of infection through hot water contaminated by the microorganism. L. pneumophila detected in water from cooling tower, showerhead in apartment of one patient, and from drainage canal of hot water supply station belonged to other allelic variants and, therefore, are not related with the outbreak.

[Genetic subgroups of Neisseria meningitidis serogroup A isolated from patients with disseminated forms of meningococcal infection in Moscow, 1969-2006].

Results of microbiological monitoring for serogroup A Neisseria meningitidis circulated in Moscow from 2002 to 2006 are presented. Using multilocus sequence-typing, molecular and epidemiologic characteristics of 32 cultures isolated from cerebro-spinal fluid of patients with generalized forms of meningococcal infection. Typed isolates belonged to 4 sequence types: CT-3349 (detected in 24 cultures), CT-2 (detected in 5 cultures), CT-75 (detected in 2 cultures), and CT-5803 (detected in 1 culture). All sequence types (except CT-5803) were detected in Moscow in previous years. Using Internet database (http://pubmlst.org/neisseria) they were genetically characterized and compared with data on serogroup A meningococci circulated in Moscow before 2002., meningococci belonging to epidemically dangerous genetic subgroup III were not detected between characterized strains. Typed isolates were distributed between subgroups VI and X, which are typical for the area under surveillance. Genetic changes in Moscow population of Neisseria meningitidis serogroup A, which manifested by shift of dominating genetic subgroup after 2002-2003, were analyzed.

[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.

[Development of amplification technology-based methods for tick-borne encephalitis virus detection and genotyping].

The development of methods for tick-borne encephalitis (TBE) virus genotyping, such as determination of nucleotide sequences, analysis of restriction fragment length polymorphism, polymerase chain reaction using genotype-specific probes with hybridization-fluorescence detection, is under consideration. The capacities and application area of varions typing techniques, such as TBE detection and genotyping in the field, autoptic, and cultural materials; study of circulating genotypes in different natural foci and in various viral vectors and carriers, are described. Each technique was tested using a large number of strains isolated from ill humans and ticks in different regions of the country and employed to investigate abundant materials.

[Detection of sapoviruses in children with acute gastroenteritis in Moscow in 2002-2003].

Sapoviruses were found, for the first time, to be circulating in children with acute gastroenteritis in the city of Moscow. On the basis of a genetic analysis, they were classified as belonging to genotypes 1 and 2. Two groups of sapoviruses that are essentially different from the strains presented now at the GenBank NCBI were described within the case study.