Vol 95, No 1 (2018)

Aim. Aim of the research is the identification of functional groups of human gut bifidoflora based on analysis of the spectrum of metabolites features, proteome, bioprofile, immunoregulatory properties and the ability to differentiate «self/non-self» among the associative microbiota. Materials and methods. The materials are 260 strains ofbifidobacteria isolated from 122 intestinal microsymbiocenoses. Experimental studies were carried out using bacteriological, chromatographic and immunological methods. Statistical processing of material is carried out by means of the package Statistica 10.0 using of k-cluster analysis and discriminant method. Results. As a result ofthe work, 3 clusters containing strains of various types of bifidobacteria were identified. The first cluster was represented by B. bifidum and was characterized by the antipeptide activity of the strains with respect to FNO-a and INF-y, IL-10. In the second cluster of the B. longum culture predominated, where the parameters of the backbone factor of microsymbiocenosis, the ability to microbial recognition, antagonistic activity and production of acetic acid were significant. In the third cluster the species composition of bifidobacteria was diverse and products of butyric, caproic acids and their isoforms were the informative tests. Conclusion. The key function of bifido-flora in the regulation of the homeostasis of the intestinal biotope is realized by the formation of functional clusters, among which the first group participates in the formation of the cytokine balance, the second group is responsible for the discrimination of associative microbiota and direct protection of the biotope from pathogens, and the third is necessary to maintain the barrier metabolic function of enterocytes in the human large intestine.

Aim. The study of the prognosis of epidemiological and economic effects of pneumococcal vaccination in laboring males with various chronic diseases. Materials and methods. Within the predictive (Markov) model, based on the published data, assessment of 5-year horizon pneumococcal vaccination of laboring males perceived effectiveness in reducing mortality, avoiding morbidity and economic loss in the country had been processed. According to the official statistics in the Russian Federation 21 575 887 laboring males are within the high risk group for contracting pneumonia. Data source for the cost of the healthcare for disease had been the compulsory health insurance system 2016 state tariffs, for the vaccination cost results of the PCV13 procurement bidding had been used. Results. Data extrapolation from national and international studies to the cohort of individuals with chronic respiratory diseases, cardiovascular diseases and diabetes mel-litus vaccinated against pneumococcal infection showed a significant decrease in the risk of underlying diseases complications (OP=0,58, p<0,05), hospitalizations number (OP=0,02, p<0,05) and expected mortality. The cost of vaccination in the evaluated group of patients was 25 869.5 min RUB. According to the modeling results PCV13 use will allow to statistically significantly decrease the number of relapses and hospitalizations that will permit to save up to 14 359.9 min rubles annually. Thus, in the two-year horizon, the total fiscal savings will amount to 2 850.30 million RUB and at least 61 702 of the patients' lives retained in a 5-year term with a single dose PCV13 administration. Conclusion. The study results indicate potential high epidemiological and clinical effectiveness of pneumococcal vaccination of the laboring males suffering from chronic diseases. Vaccination as a cost-effective investment in healthcare creates the opportunity of reductions in morbidity, number of exacerbations, hospitalization rate and mortality in the vaccinated cohort.

Aim. Evaluation of seroprevalence of antibodies to influenza A and В viruses and analysis of specimens from severe or fatal influenza cases in Russia in 2015 - 2016 and 2016 - 2017 flu seasons. Materials and methods. Determination of antibody titer in human serum samples in hemagglutination inhibition assay with reference antigens. Isolation of influenza viruses from nasopharyngeal swabs and autopsy material in cell culture. Characterization ofisolated strains. Results. In 2016, compared to 2015, the proportion of serum samples, containing antibodies to influenza viruses A(H 1N1 pdm09) and A(H3N2), increased. During the 2015-2016 season, elevated number of severe and fatal cases of influenza were registered. The majority of circulated strains belonged to the new clade 6B.1 of A(HlNippdm09 viruses. 1% of analyzed isolates carried H275Y amino acid substitution in neuraminidase and were resistant to oseltamivir. In the 2016 - 2017 season, there were less severe cases of influenza. The most prevalent were influenza viruses A(H3N2) and B/Victoria. Isolated H3N2 viruses belonged to the 3C.2a subclade and B/Victoria isolates were from the 1A genetic group. All tested strains were susceptible to neuraminidase inhibitors. Conclusions. Flu seasons 2015 - 2016 and 2016 - 2017 differed in intensity of influenza activity and in the dominant influenza A virus subtype. Immunization with vaccine, comprising new HlNlpdm09-component, is crucial for prophylaxis of influenza infection with viruses from 6B. 1 subclade in the next season. Neuraminidase inhibitors are recommended for influenza treatment.

To scientifically prove the nomenclature of the priority pathogenic biological agents (PBA) and the infectious diseases caused by them for laboratory diagnostics when ensuring biological safety of public events. PBA assessment (viruses, bacteria, biological toxins I - IV of groups of pathogenicity) was carried out, using the criteria allowing to predict their potential negative impact at the qualitative level. The evidence-based nomenclature of PBA posing the greatest threat of biological safety regardless oftheir confmedness to the territory of risk and time of risk is developed. The list included the bacterial (plague, anthrax, cholera) and viral agents (orthopoxviruses, filoviruses, arenaviruses, coronaviruses, orthomyxoviruses) of the I - II groups of the pathogenicity. The nomenclature of the widespread natural and focal (tularemia, leptospirosis, the Q fever, hemorrhagic fever with a renal syndrome, ornithosis) and the ubiquitous (brucellosis, hemorrhagic colibacillosis, a hemolytic-uremic syndrome, intestinal yersiniosis, pseudotuberculosis, Legionnaires' disease) infections capable to cause the serious complication of the sanitary and epidemiologic situation is prepared. On the basis of the carried-out assessment of dangerous biological factors the universal list of PBA for priority ensuring readiness for laboratory diagnostics during public events was created.

Aim. Our aim was to study the bactericidal effect of human serum on Borrelia miyamotoi in vitro. Materials and methods. B. miyamotoi spirochetes (strains HT31 and LB-2001) were incubated in non-immune serum of healthy donors (SHD) and in heat inactivated complement-depleted SHD, as well as in serum samples of the patients recovered from ITBB-BM. The viability, that is motility, of borrelia after incubation was investigated by dark-field microscopy. The levels ofserum antibody to B.miyamofoi-specificproteins (GlpQ enzyme and four variable major proteins Vlpl5/16, Vlpl8, Vspl, and Vlp5) were measured by specially designed plane protein microarray. Results. Borrelia fully retain their viability in non-immune SHD, but their motility is partially or completely suppressed by the addition of serum from ITBB-BM convalescents or rabbit antibodies to Д. miyamotoi. The immobilizing effect of the immune serum is substantially inhibited by its heat-inactivation, which indicates that immobilizing effect is mediated by the complement system. Conclusion. Antibody-dependent complement-mediated bactericidal action ofhuman blood serum is probably not the only and 100% effective mechanism for human defense against B. miyamotoi infection, but requires support from cellular immunity.

Aim. Study of molecular-genetic properties of Shigella sonnei-2013 strain isolated during the outbreak in dysentery in the republic Abkhazia in 2013. Materials and methods. Genetic typing of the tested strains using multilocus sequence typing (MLST). Analyzed of nucleotide sequence fragments 7 of conservative «housekeeping» genes adk, fumC, icd, mdh, purA, recA, gyrB. Sequenced of DNA fragments compared with reference sequences from database of Escherichia coli MLST. Phylogenetic analysis was performed using UPGMA method and computer program START 2. Whole-genome sequencing performed on a genetic analyzer Ion Torrent Personal Genome Machine (PGM™) using fragment libraries (shot-gun). Aligning reads have been carried out with the program GS Reference Mapper. Results. Defined sequence - type of the studied strain - ST-152, one of the most common genotypes for S. sonnei. Demonstrated the high degree of similarity obtained contig to the sequences of the chromosome and plasmids А, В, С и E strains S. sonnei 53G and S. sonnei Ss046. Identified contigs with a high percentage similarity to the sequence of virulence plasmid p026-Vir of E. coli 026:H11 (H30). In the genomic S. sonnei-2013 revealed nucleotide sequence of 136 genes were found located on the p026-Vir strain of E. coli 026:Н11 (НЗО). Discovered genes controlling biosynthesis of type IV pili involved in adhesion to abiotic surfaces and biofilm formation. Conclusion. Identified structural peculiarities of strain induced by fragments of virulence plasmid p026-Vir strain E. coli 026:H 11 (H30).

The review summarizes the basic information on the development and diagnostic capabilities of the latex agglutination test (LAT), used for detection and subsequent identification of melioidosis pathogen. According to the published literature, the use of melioidosis monoclonal antibodies of various epitope direction for coat the latex beads (suspension carrier), the main detection ingredient of this reaction, contributes to an increase in the diagnostic capabilities of this method: its sensitivity and specificity, which has been repeatedly confirmed by specialists working both in endemic zone distribution of Burkholderia pseudomallei and outside these territories. As most authors of the publications noted, after introduction of this reaction into practical work of profile laboratories, low-cost commercial products (test set of reagents for latex agglutination reaction) can find wide application both in stationary and mobile laboratories. The undoubted merits of the method are its simplicity, clarity, suitability for working with various samples from objects of the external environment and biological material, as well as obtained evidence ofthe suitability of LAT to ensure effective differentiation of B. pseudomallei from avirulent related bacteria and detection of the causative agent in the early stages of the disease for relatively short intervals, which makes it a promising method for diagnosing melioidosis, a potentially fatal infection requiring an early onset appropriate antibiotic therapy.

The review contains the current knowledge on the main issues of Burkholderia pseudomallei and Burkholderia mallei biofilm formation. The role ofknown structural elements of Burkholderia cells (flagella, type IV pili, LPS), as well as autotransporter adhesin proteins in the attachment of bacteria to surfaces, the formation of microcolonies and biofilm is described. The review also includes information of genetic regulatory mechanisms (QS-systems, RpoE-sigma factor, c-di-GMP, two-component signal transduction system), differentially expressed genes related to the formation of B. pseudomallei biofilm, role ofbiofilms in the virulence and resistance to antibiotics of pathogenic Burkholderia and their significance for the chronic processes and recurrent course of melioidosis and glanders.