Vol 96, No 4 (2019)

Aim. The aim of this study is to compare the prevalence of HIV infection in patients of large multidisciplinary hospitals in providing emergency and planned medical care and to evaluate the value of the long-term dynamics of this indicator as a quantitative characteristic of the epidemic process of HIV infection. Materials and methods. We retrospectively analyzed the results of examination for HIV infection of patients in the Sklifosovsky Research Institute for Emergency Medicine (RIEM) and Moscow Regional Research Clinical Institute (MONIKI) from 2008 to 2017. Long-term dynamics of the prevalence HIV infection were analyzed by using linear regression analysis. The intensity of trends (growth/decline) was assessed by the criteria proposed by V. D. Belyakov et al. (1981). Results. We examined for HIV infection 251 213 and 165 194 people in the research RIEM and MONIKI, respectively. For decade, the number of hospitalizations of HIV-infected patients to RIEM increased by 1.7 times, to MONIKI by 3.1 times. Prevalence of HIV infection in the patients of RIEM exceeded MONIKI ones from 3,2 to 6,0 times. At the same time, MONIKI showed a statistically significant trend towards an increase in hospitalizations of HIV-infected citizens (R2=0,8049, p=0,0004) with a pronounced average annual growth rate of 9,6% per year. Conclusion. We obtained results indicates a tendency to increase the number of recourses HIV-infected persons to general hospitals inMoscow andMoscow region. The most significant average annual increase in the prevalence over a decade period were recorded in the intensive care (+14.2%) and surgical (+9.8%) departments of MONIKI. Indicator groups of high risk of HIV infection in theMoscow region should be considered patients with urgent surgical pathology, acute exogenous poisoning of chemical etiology, as well as persons suffering from mental disorders.

Aim. To create a database of mass spectra of Yersinia pestis strains, which will differentiate the strains of the main and Caucasian subspecies of the plague agent by MALDI-TOF MS. Materials and methods. MALDITOF mass spectrometry was used to study 50 strains of Y. pestis, isolated on the territory of 7 natural plague foci of the Caucasus and Transcaucasia in the period 1950-2012. The removal of mass spectra of extracts of cells of Y. pestis was performed using the mass spectrometer Microflex LT «Bruker Daltonics». The results were processed and analyzed in FlexAnalysis programs, аnd MALDI Biotyper V. 3.0. Results. Тhis study showed that mass spectra have characteristic features that allow differentiating strains of the main (Y. pestis pestis) and subspecies (Y. pestis caucasica). Peaks characteristic of each subspecies were detected. The presence in Y. pestis caucasica subspecies peaks characteristic of the ancestral form — Y. pseudotuberculosis indicates the ancient origin of this group, which is consistent with the data of molecular genetic and WGS analysis given in other publications. Conclusion. Тhis work shows the possibility of applying the MALDI-TOF method of mass spectrometry for rapid differentiation of strains of the main subspecies Y. pestis pestis from the subspecies Y. pestis caucasica, which have different significance in the development and maintenance of the epizootic process in natural plague foci as well as different virulence for humans. Identification of the strain to the subspecies level requires carrying out culture and biochemical tests, which can take several days. The proposed method makes it possible to differentiate and obtain a result within half an hour after receiving a pure culture.

Aim. A comparative study of serological methods for the detection of the causative agent of tularemia and their evaluation. Materials and methods. We used experimental diagnostic kits and test systems for the production of serological methods: indirect hemagglutination reaction (RGA); the reaction immunofluorescence (RIF); enzyme immunoassay (ELISA) using traditional microplate; IFA after selective concentration of the pathogen of tularemia in magnoimmunosorbents (MIS); microgravimetric analysis (MGA) based on piezoresistors (SP) and surface plasmon resonance (SPR). The experiments were carried out with homologous strains of tularemia microbe (test strains) and with strains of heterologous microorganisms in model experiments on tap water contaminated with different concentrations of the pathogen. Results. The parameters of each diagnostic method are determined and evaluated according to the following indicators: sensitivity (when working with pure cultures (test strains), contaminated samples of large volumes), specificity, time of setting and taking into account the results, informativeness, determining the modes of setting and accounting. Conclusion. The above diagnostic methods have their advantages and disadvantages. Therefore, when choosing a method, the researcher should be guided by the goals pursued. So, for screening studies it is advisable to carry out the formulation of ELISA, RIF, RGA, in identifying the pathogen in large volumes and contaminated samples, the effective use of selective concentration on MIS followed by the formulation of ELISA, to identify small amounts of samples and take into account the reaction in real time, it is possible to use MGA and SPR.

Aim. To determine the boundaries of the Crimean-Congo haemorrhagic fever (CCHF) natural focus in the Russian Federation at the current stage, to clarify the range of the main reservoirs and vectors of CCHF pathogen, to assess the epidemiological capacity of the natural focus. Materials and methods. The materials of epidemiological and epizootological monitoring of the CCHF natural focus, methods of epidemiological and epizootological analysis, molecular-genetic and cartographic methods were used in the work. The findings have been treated using by software package Microsoft Office Excel 2010. Results. The unified integrity of the CCHF semi-desert-steppe natural focus, which occupies vast territory of the southern part of the Russian Federation of 831 thousand square kilometres, is science-based. Expanding the geographic area of the CCHF agent with the involvement new administrative district can be seen. The trend of shifting of the CCHF natural focus borders in a northerly direction has been established. An increasing of epidemiological capacity of the CCHF natural focus has been noted. Hyalomma marginatum ticks are the main reservoirs and vectors of CCHF virus. The genotype «Europe-1» is predominant genotype in the natural focus. Conclusion. It is necessary to improve the tactics of CCHF epidemiological surveillance using modern science-based approaches. For example, automated forecasting-modeling system, using results of multifactorial risk analysis, which have an impact on the intensity of CCHF epidemic appearances, allows to quantitative forecast epidemiological situation on this infection in the aggregate and for certain subjects of the south of the Russian Federation.

Aim. Evaluation of herd immunity prior to the 2017-2018 influenza season, and characterization of influenza viruses isolated from severe or fatal influenza cases and from influenza cases in people vaccinated in the fall of 2017. Materials and methods. Evaluation of herd immunity in hemagglutination inhibition assay. Isolation of influenza viruses. Antigenic and genetic analysis. Results. Prior to epidemic season 33-47% of blood sera samples collected on the territory of Russia showed presence of protective antibody titers against vaccine strains of influenza A, 24-30% of samples — against B/Victoria. During 2017-2018 epidemic season 87 influenza A and B viruses were isolated. A(H1N1)pdm09 strains belonged to clade 6B.1, B/Yamagata strains to clade 3, and B/Victoria strains to clade 1A; they were antigenically similar to corresponding vaccine strains. A(H3N2) viruses belonged to clade 3C.2a and were difficult to characterize antigenically. One strain of influenza virus А(H1N1pdm09) was resistant to oseltamivir and had H275Y amino acid substitution in neuraminidase. All other isolates were susceptible to neuraminidase inhibitors. Conclusion. Influenza vaccination with vaccine effective against current circulating strains and treatment with neuraminidase inhibitor drugs at first manifestation of clinical signs of influenza disease are effective means of population protection against influenza.

Aim.The development of a semi-synthetic nutrient medium that provides the maximum amount of capsular polysaccharide (CPS). Materials and methods. We used the strain 521 of S. pneumoniae serotype 23F. Cultivation was carried out in test tubes with 10 ml of polysynthetic nutrient medium of a specific composition. The amount of polysaccharide in the samples was determined using rocket immunoelectrophoresis. Building models and comparing the effects of various components was carried out according to the methodology specified in the tutorial. The calculation of the coefficients of the equation and the assessment of the adequacy of the equations themselves was carried out using RStudio version 1.0.153. Results. As a result of a series of experiments, the coefficients of the regression equations were calculated, their significance was evaluated, and models of dependence of biomass production and CPS were constructed depending on the composition of the nutrient medium. To solve the problem, an experiment was carried out according to the Box-Wilson method. The peptone and glucose concentrations were selected as optimized parameters. The step size ΔSi in the increasing gradient direction was calculated based on the coefficients of the regression equation. At the same time, the exact nature of the dependence was determined. The optimal calculated concentrations of peptone and glucose, at which the formation of CPS is maximum, are 32.6 and 12.1 g/l, respectively. In this case, the forecast yield of the polysaccharide is 239 mg/l. Conclusion. Using the method of fractional factorial experiment, models of the dependence of the biomass amount of S. pneumoniae and its capsular polysaccharide on the composition of the nutrient medium were obtained. The optimal concentrations of the components of the medium were found, which make it possible to increase the level of biomass formation by 10% compared to the standard formulas, and the CPS — by 1.5—2 times.

Varicella Zoster Virus (VZV) is a highly contagious viral agent of the Herpesviridae family, which has a strict species specificity, and causes two different diseases — chickenpox, mainly in children, and herpes zoster — more often in the elderly. Obtaining additional information about the life cycle of the virus, its biology, pathogenetic features of the complications caused by it, will contribute to the emergence of more advanced methods of diagnosis and prevention, the development of new experimental approaches that allow to study the innate and adaptive mechanisms of immune protection in VZV-infection.

In many countries of the world despite the extensively vaccination against pertussis has increased the incidence of the whooping cough in all age group of the population. The MLST, MLVA and CGH investigations revealed the differences in genotypes between the vaccine strains B.pertussis and the circulating isolates B.pertussis in consequence of adaptation of the bacterium B.pertussis to the immunized hosts. It is lead to waning immynity and outbreak of incidence of pertussis. The mutations in the genes encoding the major virulence factors, the allelic polimorfism and decreasing the genome size of B.pertussis strains are the basis of the B.pertussis adaptation to the immunized hosts and dependent on the type of the vaccine used for immunization Programme. In countries that use acellular pertussis vaccine for vaccination programme the dominant isolates genotypes are: ptxА1-ptxС2- ptxР3-prn2- tcfA2-1-fim3-2 и ptxА1- ptxС2- ptxР3-prnА2- tcfA2- fim2-1- fim3-1, and that use the cellular pertussis vaccine the dominant isolates genotypes are ptxА1-ptxС1- ptxР1-prn1- tcfA2- fim2-2 fim3-1 и ptxА1- ptxС1- ptxР1- prn2- tcfA2- fim2-1- fim3-1. The constant monitoring of the genotypes of isolates B.pertussis is necessary to reveal the dominant genotypes and include them in the national immunization programme in combination with vaccine strains B.pertussis.

For interepidemic periods of natural focal sapronoses, various ways of maintaining the viability of pathogens in terrestrial parasitic systems are associated with various adaptation strategies necessary for the conservation of the population. Unlike spore-forming bacteria, sapronose pathogens use stable cellular forms — a viable but uncultivated state and persistence. The implementation of these strategies is due to the influence of various stress factors of the habitat and is characterized by a decrease in metabolism, a change in the morphology and physiology of the bacterial cell, and the cessation of its replication. It is important that stable forms of cells retain virulence and, when favorable conditions come, they are again transformed into active vegetative forms. The discovery in recent years of genetic modules of bacterial toxin-antitoxin systems has made it possible to uncover complex regulatory molecular mechanisms for preserving the pathogenic potential of stable forms of pathogens of natural focal sapronoses in interepidemic periods.

Aim. Obtaining hybridomas, stable producing specific monoclonal antibodies against Burkholderia mallei and Burkholderia pseudomallei antigens. Materials and methods. The microbial cultures from State Collection of Microorganisms from the Branch of 48 CSRI of the Defense Ministry of Russian Federation (Kirov) and BALB/c mouse were used in research. Hybridization of B lymphocytes with SP2/0-Ag14 myeloma cells was performed by G.Kohler and C.Milstein procedure in De St. Fazekas and D.Scheidegger modification. The specific activity of immune sera, hybridoma supernatants, ascites and evaluating the diagnostic capabilities of monoclonal antibodies was studied by ELISA. Results. Hybridomas, producing monoclonal antibodies against causative agents of glanders and melioidosis antigens, were obtained and characterized. Obtained hybridomas are active and stable antibody producers after repeated in vitro and in vivo passaging. Immunoglobulins from obtained ascites were isolated. Antibodies provided the greatest sensitivity and specificity were selected. Conclusion. Monoclonal antibodies, producing by obtained hybridomas may be used for creating of immune biological tests.