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Relevance. The identification of determinants of the human genome, such as single nucleotide polymorphisms (SNPs), in association with various disease patterns, including infectious diseases, is one of the most actively developing areas of scientific research in the world.. Hepatitis C (HC), which remains a serious global health problem, belongs to the number of infections that attract the attention of specialists.Aims. Determination of genetic markers of hepatitis C virus (HCV) natural elimination and assessment of their role as a monitoring parameter of the epidemiological surveillance system.Materials and methods. The study included 660 people divided into 2 groups: persons with chronic HC (CHC) and blood donors (indicator group of the healthy population). In the studied groups, the following SNPs were typed: rs1143634, rs1143627 (IL-1B); rs4251961, rs419598 (IL1RN); rs1800795 (IL6); rs1800896 (IL-10); rs4986790 (TLR4); rs4374383 (MERTK). The associative relationship between SNPs and CHC alleles was identified using logistic regression analysis within four models (codominant, dominant, recessive, and overdominant). Additionally, the significance of polymorphisms at the intragenic and intergenic levels was assessed using modern bioinformatic resources in the field of functional genomics.Results. In this study, genotypes associated with the natural elimination of HCV were identified. Paired combinations of IL 1RA/IL-1B genotypes associated with the probability of the formation of CHC have been established. It is shown that synonymous SNPs can be associated with any characteristics of the pathological process, which can be explained by disequilibrium in coupling with functionally significant alleles of other genetic loci.Conclusion. The detection of the association of SNPs with clinical manifestations of the pathological process is not final and requires further study taking into account ONP coupling groups.

Relevance. Unencapsulated strains of meningococcus (NmNG) very rarely cause invasive meningococcal disease. A new ciprofloxacin-resistant strain NmNG ST-175 cc175, which has recently caused several cases of invasive meningococcal infection in Europe, has been discovered in the Russian Federation.Aim. To compare the new Russian strains of NmNG ST-175 with the already characterized NmNG ST-175 and to analyze the genetic markers associated with antibiotic resistance.Materials and methods. The nucleotide sequences of NmNG ST-175 strains of more than 2 million base pairs were exported from the PubMLST database. Comparison was carried out for 1605 core genome loci using the N. meningitidis cgMLST v1.0 ". Genetic relationships of 127 NmNG ST-175 strains, including 8 Russian carrier strains, were visualized using the SplitsTree software (version 4.16.2).Results. Of the eight Russian strains, six found themselves in a cluster with German and Swedish isolates that caused invasive meningococcal infection. Two more Russian strains were closest to the isolates of the cluster, including carrier isolates from England. Seven strains showed resistance to ciprofloxacin and possessed the gyrA-187 and gyrA-152 alleles, which, based on the phylogenetic analysis of the alleles, belonged to the genetic branches of Neisseria cinerea and Nm.Conclusion. Protein vaccines alone could potentially provide protection against ST-175 NmNG. It seems promising to study the antigenic characteristics of Russian Nm strains, including NmNG ST-175, to assess the potential vaccination coverage with existing protein vaccines, the possibility of their registration on the territory of the Russian Federation, as well as the development of domestic vaccines.

Relevance. Population migration can play a crucial role in the spread of invasive strains of meningococcus, initiating outbreaks of meningococcal infection, and changing the incidence at the local level.Aim. To assess the prevalence of meningococcal carriage among migrants arriving in Moscow and to characterize the antigenic and genetic properties of carrier strains of meningococcus.Materials and methods. The study was conducted in March 2020 at the bases of the Multifunctional Migration Center of Moscow and the Federal Budget Institution of Science «Central Research Institute of Epidemiology». Samples of nasopharyngeal mucus were collected from 352 people. Nasopharyngeal strains of meningococcus were identified and identified using microbiological, serological, and molecular biological methods.Results. The overall level of the carriage was 5.7%. Of the twenty selected strains, 10 have a serogroup defined: Y – 5 strains, W - 3, A, and B – 1 each. The obtained genetic and antigenic characteristics do not allow talking about the import into the RF of representatives of known hypervirulent clonal complexes. In this study, strains were identified that are part of the clonal complex ST-175 complex, which has not been previously described in the Russian Federation.Conclusion. It seems promising to continue the dynamic monitoring of carriage of meningococcus in various groups, including among people entering the country to obtain a migration patent, as well as identifying risk factors for acquiring carriage. The data obtained will supplement current information on the incidence of the generalized form of meningococcal infection and will be crucial for determining the epidemiology at the country level, the population groups responsible for the transmission of the disease, and the need for targeted vaccination.

Hemorrhagic fever with renal syndrome (HFRS) is a zoonotic infection disease caused by Orthohantavirus which belongs to Hantaviridae family. This article is a brief review of recent data about genetic factors which play a role in individual predisposition toward HFRS. There are reports discovered associations of polymorphic sites with HFRS severity and risk complications. Polymorphic sites in genes which code proteins of immune (МНС, TNF, IL1) and endothelial (VE-cadherin) systems, blood coagulation (SERPINE1, ITGA2B, NOS) and detoxification (CYP1A1, GSTP1) systems and their links with disease are described in this article. HLA haplotypes B*08-DRB1*03 and B*46-DRB1*09, B*51-DRB1*09 are associated with severe forms of HFRS-PUUV and HFRS-HTNV respectively. TNF A-allele and AA-genotype in -308G>A SNP (rs1800629), CDH5 ТТ-genotype in 1550T>C SNP, SERPINE1 G-allele in -844A>G SNP (rs2227631), alleles HPA3 b, NOS2A*11 and NOS2A*11/NOS2A*12-genotype, CYP1A1 1А2С-genotype in SNP (rs1048943) and GSTP AG-genotype in SNP (rs1695) demonstrated associations with severe HFRS. Differences in the expression levels of GATA3, T-BET, CD3, IFNβ, NFkB, STAT1 and MxA genes in cell cultures stimulated by hantavirus. Expression of GATA3 was significantly higher in cell cultures of patients with severe HFRS than with a mild form. In contrast, MxA gene expression was up-regulated in cell cultures of patients with mild HFRS-PUUV. Considering individual genetic factors of HFRS patients would allow defining the best tactic of therapy and prophylaxis in this way. And as a result of applying this treatment in the clinical practice decrease of unfavorable disease outcome would occur.

Introduction. The invasive meningococcal disease (meningitis and/or septicemia) is actual problem of public health in Russia. Neisseria meningitidis isolates are classified into serogroups, PorA/FetA VRs, sequence types and clonal complexes. The growth of the invasive forms of meningococcal infection caused by isolates with «W: P1.5,2: F1-1: ST-11 (cc11)» profile requires attention for extended genotyping because the discriminating ability of classical MLST and antigens typing does not allow to answer the question about genetic and antigenic features of the pathogens and their epidemic potential. Materials and Methods. Four N. meningitidis serogroup W isolates associated with invasive meningococcal disease in Moscow (Russia) were characterized by next-generation sequencing. Three isolates were sequenced directly from cerebrospinal fluid samples and one -as a bacterial culture. All isolates were characterized earlier and the data were published in the PubMLST data base (id38565, id38573, id50225 and id50241). Genomic DNA was sequenced on Illumina MiSeq instrument. Results and Discussion. Obtained sequences allowed us to characterize four meningococci isolates for more than 1400 loci from the core genome MLST scheme. We have analyzed the core genome MLST scheme information about surface-antigen coding sequences. Housekeeping genes sequences were used to determine eMLST profile, ribosomal protein genes and some antibiotic resistance associated genes. We have characterized some ribosomal protein genes and antibiotic resistance associated genes. Based on eMLST profiles we noticed that there are at list two clones of N. meningitidis serogroup W inside complex ST-11/ET-37 clonal complex circulating in Moscow during 2016. An eMLST profile of isolates id50225 and id50241 differs in 3 loci out of 20. Application of the approach based on next-generation sequencing in routine epidemiological surveillance dramatically increases the amount of data and genotyping discriminating ability.