Introduction. Infection of canids with canine parvovirus (CPV), especially in puppies, leads to serious damage to the gastrointestinal tract in a short period of time, up to a fatal outcome. In this regard, early and rapid diagnosis is crucial for initiating therapy and preventing the spread of infection. In this connection, immunochromatographic analysis (ICA) is the preferred method because it allows rapid detection of virus infection. In addition, this method is highly specific and does not require complex laboratory equipment, which greatly simplifies its use in comparison with other common methods for detecting canine parvovirus. The aim of this study is the development of an ICA test system for the detection of the VP2 protein of canine parvovirus. Materials and methods. Monoclonal antibodies to the recombinant VP2 protein of canine parvovirus were obtained using hybridomic technology. Colloidal gold is synthesized by the citrate method. Results. Monoclonal antibodies (MABs) against the VP2 protein of canine parvovirus were obtained and characterized, colloidal gold (AuNPs) was synthesized, the conditions for conjugation of MABs with AuNPs were selected, and the optimal ratios of the components of the test system were determined. The visual limit detection (vLOD) was 1.56 ng/mL. The developed ICA test system has shown high diagnostic efficiency in model experiments with a known concentration of VP2, as well as in sick animals with a confirmed diagnosis. Conclusion. An ICA test system has been developed to determine the VP2 protein of canine parvovirus. The resulting test system can be used as a fast and effective diagnostic tool for detecting CVP in the canine clinical specimens.
The aim of the review was to analyze current literature data on the mechanisms by which the influenza A virus causes a decrease in the level of the SLC7A11 (xCT) protein in human cells, which contributes to the initiation of ferroptosis. The literature search was performed in the eLIBRARY.RU, CyberLeninka, Google Scholar, PubMed databases for the period 2009-2026. Data are presented on the role of the Xc⁻ transport antioxidant system and its key subunit SLC7A11 in the pathogenesis of influenza infection in the context of ferroptosis induction. The Xc− system mediates the import of cystine, which is essential for the synthesis of glutathione, the primary intracellular antioxidant. The molecular mechanisms of ferroptotic cell death are described, including Xc− dysfunction, activation of the transferrin receptor TfR1, lipoxygenase ALOX15. Data on experimental evidence of ferroptosis induction upon influenza virus infection, obtained using A549, 16HBE, BeWo cell lines as well in mouse cells, are presented. This evidence includes increased expression of TRIM family proteins, TNF-α, and elevated TGF-β1 mRNA levels. Hypothetical models of indirect pathogen-mediated effects are discussed, suggesting SLC7A11 suppression driven by pro-inflammatory cytokines (TNF, IFN-γ, IL-1β, TGF-β1) and proteins p53 and BAP1. The need for further research to confirm the contribution of the pathways discussed and to assess their clinical potential as targets for therapy or biomarkers is emphasized.
Background. Bats are a natural reservoir for various viruses, including SARS-CoV-2. Bat cell cultures are used to study the cellular tropism of zoonotic viruses, which helps determine the range of hosts and their possible origin. The aim of the study is to assess the sensitivity of the bat kidney cell primary culture of Murina hilgendorfi to infection by different genetic variants of SARS-CoV-2. Materials and methods. To study the tropism of coronaviruses, a primary culture of M. hilgendorfi bat kidney cells was prepared and infected with strains of different SARS-CoV-2 genetic variants from the Collection of Pathogenic Microorganisms of the G.P. Somov Research Institute of Epidemiology and Microbiology of Rospotrebnadzor (Wuhan, Delta, and Omicron). Vero-E6 cells were used as a positive control. The effectiveness of viral replication was assessed in dynamics by cytopathogenic effect (CPE) and RT-qPCR in the supernatants of cell cultures, with determination of the threshold cycle (Ct). Results and discussion. On the 7th day cultivation of the primary culture of the bat kidney cells, a heterogeneous monolayer of cells with 70–80% confluency was formed. The monolayer was represented by fibroblast-like and epithelial-like cells. After infecting a culture of bat kidney cells with different SARS-CoV-2 genetic variants, the virus’s CPE was already evident at the initial time points and increased over the period of observation. SARS-CoV-2 RNA was detected in the supernatant of bat kidney cell lysate on the 2nd day after infection, by the 6th day, the Ct values in RT-qPCR decreased for all three genetic variants. This indicates that coronaviruses replicate in bat kidney cells. The reproduction of coronaviruses in the kidney cells of M. hilgendorfi indicates the possibility of virus carriage by representatives of this species, as well as their potential participation in the epidemic process as carriers of viruses. This, in turn, allows us to talk about the role of bats in the formation of natural reservoirs of coronavirus infection. Conclusions. The primary culture of kidney cells of M. hilgendorfi was obtained for the first time. This culture is susceptible to strains of different SARS-CoV-2 genetic variants (Wuhan, Delta, and Omicron), as confirmed by CPE and RT-qPCR. According to the results of the RT-qPCR analysis, no differences in sensitivity were observed between the three genetic variants.
INTRODUCTION:Rotaviruses exhibit a high degree of variability, which is ensured by the process of reassortment and antigenic drift. This leads to significant genetic diversity, including the emergence of strains with rare and unusual genotypes. This study, for the first time, provides a molecular genetic characterization of a rare RVA strain with the genotype G2P[9] based on all genome segments. AIM OF THE STUDY:To conduct a molecular genetic characterization of a rare strain of RVA genotype G2P[9] based on all genome segments, as well as to compare the strain with previously characterized representatives of subgroup BA222 from Nizhny Novgorod. MATERIALS AND METHODS:Rotavirus-positive stool samples from children were analyzed using PCR-genotyping and PAGE. For the isolate under study, cDNA fragments of each of the 11 genes (VP1-VP4, VP6, VP7, NSP1-NSP5) were sequenced. Nucleotide and amino acid sequence analysis and phylogenetic tree construction were performed using MEGA X. RESULTS:In the period 2022-2023, a single strain of the unique genotype G2P[9] was identified in Nizhny Novgorod, characterized by a "broad" RNA electrophoretype (G2-P[9]-I2-R2-C2-M2-A3-N2-T3-E3-H3). The study showed that the origin of this strain is associated with reassortment processes between Nizhny Novgorod Wa- and BA222-like RVA, as well as isolates of the G3P[9] genotype from China. The studied strain, along with rotaviruses from China, differed from the Nizhny Novgorod BA222-like strains by the presence of 43 nucleotide substitutions in nine genes. These differences resulted in ten amino acid substitutions, eight of which were radical. All radical substitutions were located in the functionally active regions of the VP1, VP3, and VP4 proteins, which play a key role in the replicative cycle of rotaviruses. DISCUSSION:We characterized a strain with the rare G2P[9] genotype based on its complete genotype for the first time in Russia and globally. These results expand our understanding of the diversity of reassortant rotaviruses and complement our knowledge of the genotypic structure of the rotavirus population in Nizhny Novgorod. CONCLUSION:The wide genetic diversity of rotaviruses, maintained by reassortment and antigenic drift, may facilitate rotaviruses' ability to overcome immunological pressure. Therefore, continuous molecular monitoring of circulating rotavirus variants is necessary to monitor the emergence of new variants and assess changes in rotavirus virulence following reassortment processes.
The global rise in antimicrobial resistance (AMR) poses an urgent threat to public health, and novel alternatives to traditional antibiotics are needed. One of the most promising options is bacteriophages, viruses that infect and destroy bacteria. Once overshadowed by the discovery of antibiotics, phage therapy is now regaining attention, driven by advances in genomics, synthetic biology, and targeted medicine. This review examines the biology, diversity, and therapeutic use of bacteriophages in treating bacterial infections, especially those caused by multidrug-resistant pathogens. It also discusses how phages act through natural mechanisms, such as lytic enzymes (holins, endolysins, and muralysins), and highlights new genetic engineering techniques, such as CRISPR-Cas systems, phage recombineering, and synthetic genome reboots. In addition to clinical applications, we evaluate phages as biocontrol agents for food safety, environmental sanitation, and biofilm management. Additionally, the article explores key issues in phage therapy, including regulatory frameworks, formulation stability, dynamics of phage-host resistance, and the importance of rapid diagnosis. When properly integrated into modern health and biotechnology practices, bacteriophages offer significant potential and a sustainable solution to the global challenge of antimicrobial resistance.
INTRODUCTION:Measles, mumps and rubella viruses are highly contagious viruses that can cause serious clinical outcomes, complications and death. Neutralizing antibodies against measles, mumps and rubella viruses are a good indicator of clinical protection against these infections, but they are difficult to measure. THE AIM:To develop a serological glycoprotein-based passive hemagglutination reaction (gpPHAR) tests for the detection of neutralizing antibodies to measles, mumps and rubella viruses. MATERIALS AND METHODS:Human and animal cell cultures from the collection of the I.I. Mechnikov Research Institute of Vaccines and Sera were used; vaccine strains of measles, mumps and rubella viruses; monoclonal antibodies to measles and rubella virus glycoproteins, human and animal immune sera; formalized sheep erythrocytes sensitized with viral glycoproteins; virus neuralization test (VNT), gpPHAR and gpELISA. RESULTS:Viral glycoproteins of measles, mumps, and rubella were extracted from infected cell cultures. Comparative titrations of human and animal immune sera to measles, mumps, and rubella viruses in VNT, gpPHAR, and gpELISA have been performed. Unambiguous titers of neutralizing antibodies have been established. Titration of homologous and heterologous immune sera to three viruses was performed in the gpPHAR. The absence of cross-immunoreactivity to other viral agents has been established. The titers of the immune sera of patients with measles, mumps, and rubella infections were determined in the gpPHAR and gpELISA assays. Identical titers of neutralizing antibodies were found in both serological tests. CONCLUSION:The gpPHAR serological tests has been developed to evaluate neutralizing virus-specific antibodies to measles, mumps and rubella in patients.
OBJECTIVE:To evaluate how influenza infection affects the hypolipidemic effect of a novel combined drug - Prenophytol based on polyisoprenoids (sodium polyprenyl phosphate and beta-sitosterol) in mice with experimental dyslipidemia. MATERIALS AND METHODS:In BALB/c mice with experimentally induced dyslipidemia, the impact of Prenophytol on lipid metabolism parameters was assessed. Currently the drug is at the stage of clinical trials (Roszdravnadzor's permission to conduct clinical trials No. 362 dated 08/14/2025). A subset of animals was infected with influenza A/California/07/2009 (H1N1) virus. RESULTS:Administration of the drug to dyslipidemia mice resulted in a significant reduction in total cholesterol, triglycerides, and LDL levels, along with a significant increase in HDL. However, in the presence of influenza infection, the hypolipidemic effect of Prenophytol was markedly attenuated: only cholesterol levels decreased significantly, whereas changes in triglycerides, LDL, and HDL did not reach statistical significance. CONCLUSIONS:Influenza infection diminishes the therapeutic efficacy of the Prenophytol in the treatment of dyslipidemia. These findings indicate that concomitant viral infections must be taken into account when designing dyslipidemia treatment regimens and conducting clinical trials of this drug.
INTRODUCTION:Powassan virus (POWV) is a tick-borne orthoflavivirus capable of causing neurological diseases. In the Russian Far East, the area affected by POWV overlaps with that of another neurotropic orthoflavivirus, tick-borne encephalitis virus (TBEV). Currently, there are no differentiated test systems for specific detection of POWV in the presence of TBEV. The aim of this work is to create differentiating test systems for the detection of POWV in a mixture with TBEV and other orthoflaviviruses. MATERIALS AND METHODS:We constructed a genome alignment of eight POWV and five TBEV strains to select differentiating primers using MEGA X. To assess the specificity of the assay, we used POWV, several TBEV strains, and other orthoflaviviruses. PCR and qPCR were performed with the selected oligonucleotides, and the specificity of amplification was verified by electrophoresis in agarose gel and Sanger sequencing. cDNA was obtained from virus-containing material by isolating RNA and performing a reverse transcription reaction. RESULTS:The selected oligonucleotides for the qPCR-based differentiation system ensured specific detection of POWV without detecting signals from other orthoflaviviruses. The assay's limit of detection was 102 copies/sample. Analysis of mixed samples containing POWV and TBEV demonstrated no distortion of the measurement results. Furthermore, differentiating oligonucleotides were selected and tested to amplify extended regions of the POWV and TBEV genomes for subsequent sequencing and phylogenetic analysis. CONCLUSION:A laboratory technique based on PCR has been developed that allows to detect the POWV in samples containing other orthoflaviviruses.
The relevance of the conducted study is determined by the high epidemiological significance of adenovirus in the structure of acute respiratory viral infections (ARVI), particularly among military personnel. Previously, adenovirus was identified in 90% of cases of patients with community-acquired pneumonia hospitalised from organised military groups, leading to significant lung damage, various disabling complications, and possible fatal outcomes. The aim of this study was to investigate the genetic diversity of adenoviruses detected in patients with respiratory infections among military personnel during the 2023-2024 influenza and ARVI epidemic season in the Sverdlovsk Region. MATERIALS AND METHODS:Sanger sequencing was performed for 79 clinical samples (nasopharyngeal swabs) that tested positive for adenovirus. The samples were collected from military personnel exhibiting symptoms of ARVI who were receiving treatment in military medical institutions in the Sverdlovsk Region during the 2023-2024 influenza and ARVI epidemic season (October to February). RESULTS:Six genetic variants of adenovirus were identified: B3, B7, B14, B55, C2, and C5, with genotype B55 being predominant and associated with severe and moderately severe disease. CONCLUSION:The study provides insight into the genetic diversity of adenoviruses circulating among military personnel in the Sverdlovsk Region during the 2023-2024 epidemic season. Genetic surveillance of circulating adenoviruses is essential for developing specific preventive measures, improving non-specific prevention methods, and identifying optimal drugs for aetiotropic therapy.
INTRODUCTION:The spread of tick-borne encephalitis virus (Orthoflavivirus encephalitidis) continues. Existing vaccines have several limitations. Research new vaccine platforms will enable the development of more effective strategies of disease prevention. MATERIALS AND METHODS:The constructs for producing vaccine preparations were obtained using the methods described earlier. Study of the effectiveness of candidate vaccines based on chimeric yellow fever virus, adenovirus serotype 25 and mRNA encoding a fragment of the tick-borne encephalitis viral polyprotein corresponding to the PrM and E regions, immunogenicity and protective efficacy was performed using BALB/c mice. The neutralizing activity assessment of animal sera and mice challenge were performed using the tick-borne encephalitis virus strain Sofjin-Chumakov. RESULTS:It was established that immunization of animals with mRNA encoding the PrM and E regions of the viral polyprotein of tick-borne encephalitis virus resulted in the induction of a higher level of neutralizing antibodies compared to the other vaccine platforms studied in the immunization schedule used. In addition, this platform provided 100% protection of animals from the lethal infection caused by the tick-borne encephalitis virus. CONCLUSION:The study demonstrated that delivery of the nucleotide sequence encoding the PrM and E regions of the tick-borne encephalitis virus polyprotein within mRNA elicits a pronounced humoral immune response during animal immunization. These results demonstrate the fundamental feasibility of effectively expressing the same tick-borne encephalitis virus antigen in various vaccine platforms, each with its own advantages and limitations.
INTRODUCTION:The identification of I/II genotype recombinant African swine fever virus (ASFV) in China (2021) and its subsequent introduction to Primorsky region of Russia (2023) is a new challenge in control against ASF. The potential recombinant virus circulation may negate efforts to develop vaccines against ASF, vaccines that are based on genotype II strains) do not provide protection against recombinant virus. The aim of the study was to develop qPCR for differentiation of genotype I and new recombinant ASFV variant in clinical samples from infected domestic pigs and wild boars. MATERIALS AND METHODS:Samples of viral culture suspensions and biological material from pigs, ASF- free and infected with the recombinant ASFV strain Primorsky 2023/DP-4560 or genotype II strains were used. Positive control sample and standard plasmid were obtained using complex molecular cloning techniques to construct circular and linearized forms of plasmid pJET1.2_IREC. RESULTS:Primers and a TaqMan probe (modified with LNA, locked linear nucleic acid) were designed to the fragment of MGF 110-1L gene (93 bp). The specificity of RT-PCR was enhanced by increasing the annealing temperature to 65°C. Developed method had precision (repeatability (CV = 0.7-1.3%) and reproducibility (CV = 2.76-5.69%), 100% diagnostic specificity, 96% clinical sensitivity, and high linear dynamic range (R2 = 99.62) and efficiency (E = 95%). The limit of detection was 7 copies/µL (95% CI: 4-10 copies/µL) or 70 copies/per reaction. CONCLUSION:The monoplex RT-PCR has been developed to study the extent of circulation in Russia of atypical variants originating from East Asia.
Introduction. Epstein–Barr virus (EBV) is a widespread gamma-herpesvirus associated with a number of malignancies, including nasopharyngeal carcinoma and gastric cancer (GC/EBV+). The primary oncogenic protein of EBV is latent membrane protein 1 (LMP1). Genetic variability of the LMP1 protein affects its oncogenic activity and clinical manifestations. Objective. To investigate the optimal threshold value for EBV viral load, determine the correlation between high viral load and the detection of the LMP1 gene in the blood of patients with GC/EBV+, and to identify mutations in the C-terminal domains of the LMP1 gene that may affect protein function. Materials and methods. Total DNA was extracted from 227 blood samples of GC patients. The LMP1 gene was amplified using nested PCR. EBV DNA viral load in blood samples was analyzed by qPCR, followed by receiver operating characteristic (ROC) analysis and interquartile range (IQR) assessment. A selection criterion for positive DNA samples (EBV+) was established based on the mean viral load and ROC threshold. Results. ROC curve analysis and descriptive statistics identified 23 EBV-positive (EBV+) DNA samples, with the following results: AUC (area under the curve) = 0.83, optimal threshold 526.92 copies/reaction, sensitivity 0.69, specificity 0.87, and mean viral load: 513.5 copies/reaction. A statistically significant association was found between detection of the LMP1 gene in the blood and viral load level (χ2 test p = 0.018; Mann–Whitney U test p 0.0001). Additionally, synonymous and nonsynonymous mutations were identified in regions of LMP1 gene coding the C-terminal activating domains (CTAR1 and CTAR2). Conclusion. The findings highlight the heterogeneous molecular nature of EBV-associated gastric cancer, including genetic mutations in the LMP1 gene.
The aim of this study was to determine the level of humoral immunity to the West Nile virus (WNV) in the Moscow region population after the end of the outbreak in October 2021, as well as to confirm the specificity of antibodies to WNV by comparatively testing patient sera for antibodies to the antigenically related endemic tick-borne encephalitis orthoflavivirus (TBEV) using ELISA-IgM, ELISA-IgG, and 50% plaque reduction neutralization test. Materials and methods. We analyzed 1,594 sera from outpatients-residents of Moscow and the surrounding region–who underwent outpatient examination in the winter of 2021 at Infectious Diseases Clinical Hospital No. 1 in Moscow (IKB No. 1) and medical institutions of the Moscow Regional Research Institute named after M.F. Vladimirsky Regional Research Institute (MONIKI) conducted a study without any connection to WNV infection in the summer-autumn of 2021. Results. All samples were negative in ELISA-IgM test with WNV and TBEV antigens. In an ELISA-IgG test with the WNV antigen, antibodies were detected in 64 samples (4.0%). All samples were tested for IgG antibodies to TBEV in an ELISA and neutralizing antibodies to WNV and TBEV in a 50% plaque reduction neutralization test. Specific antibodies to WNV were detected in 44 samples (68.8%), to TBEV in eleven (17.2%), and group-specific antibodies in nine (14.0%). According to the total data from the test of 1,594 sera from residents of the Moscow region, specific antibodies to WNV were detected in 2.8% of cases, to TBEV in 0.7%, and group-specific antibodies in 0.6%. Ten of the 11 individuals with specific IgG antibodies to TBEV were undergoing outpatient examination at Moscow’s Infectious Diseases Clinical Hospital No. 1 for a history of tick-borne encephalitis or for post-vaccination immunity testing following vaccination against this infection. The detection rate of specific antibodies to WNV in similar studies conducted in the same region in 2013 was 0.2%, while in 2021 it was 2.8%. The difference between these rates is statistically significant (p 0.01). Conclusion. Based on these data, it can be concluded that sporadic undiagnosed cases of WNV infection occurred in Moscow and the surrounding region between 2013 and 2021.
Investigating the mechanisms of viral attachment and entry into cells is crucial for understanding viral pathogenesis and developing therapeutic strategies. The aim of this review is to characterize pseudo-typed particles based on the vesicular stomatitis virus (VSV) as a convenient and effective tool for studying viral entry into cells, based on literature data (PubMed, Scopus, and Web of Science), and to determine the prospects for combining this method with genetic and protein-based approaches. VSV, a member of the Rhabdoviridae family, has a remarkable capacity for pseudotyping, which involves the replacement of its native glycoprotein (G) with envelope proteins from other viruses. This feature enables the modeling of the cell entry process without the need for wild-type viruses. The VSV genome is modified by deleting the G gene and incorporating reporter genes (e.g., GFP or luciferase), thereby facilitating the quantitative assessment of infectivity. The methodology for generating pseudoviruses involves a two-plasmid cotransfection system in cell lines (e.g., HEK293T), with plasmids encoding the VSV structural proteins and the target viral envelope proteins. The advantages of the VSV system include high particle titers, rapid reporter signal manifestation, and the feasibility of work under Biosafety Level 2 conditions. However, limitations are associated with differences in the distribution of viral proteins on the surface of pseudoviruses compared to native virions, necessitating additional data validation. Conclusion. Methods for analyzing virus-cell interactions were studied, such as Virus Overlay Protein Binding Assay (VOPBA), RNA interference, CRISPR/Cas9 knockout, and gene overexpression. These approaches allow for the identification of cellular receptors, investigation of specific protein functions, and assessment of the impact of mutations. Future prospects for the application of VSV pseudoviruses include screening viral entry inhibitors, analyzing antibody neutralization, and vaccine development. Despite technical limitations, pseudotyped particles remain an indispensable tool for studying highly pathogenic and fastidious viruses. For the present review, a literature search was conducted in the PubMed, Scopus, and Web of Science databases.
Introduction. Herpes simplex virus type 1 (HSV-1) causes various diseases in humans that can lead to disability and death. Current treatments are effective and relatively safe. However, the high prevalence of HSV, the necessity for long-term therapy associated with the development of drug resistance in the virus (mainly in immunocompromised patients) and severe side effects of second-line drugs complicate treatment. Obviously, there is a necessity to develop therapeutic agents with a new mechanism of action and new ways of influencing herpes infection to improve the effectiveness of therapy. The combined use of drugs with different mechanisms of action is one such approach. The aim of the study is to evaluate the antiviral activity of combinations of LAS-131 ((3S)-4-[6-(purin-6-yl)aminohexanoyl]-3,4-dihydro-3-methyl-7,8-difluoro-2H-[1,4]-benzoxazine) with basic antiherpetic drugs and with two new compounds. Materials and methods. The effect of LAS-131 combinations against HSV-1 was studied by constructing an isobologram and calculating the fractional inhibitory concentration index. Results. LAS-131 selectively inhibits the reproduction of acyclovir-sensitive and -resistant HSV-1 variants (IC50 is 1.95 μg/mL, selectivity index is 63). Its target protein is the large subunit of the terminase complex (pUL15). When LAS-131 is used in combination with viral DNA polymerase inhibitors (acyclovir and related compounds) or with the minor-groove inhibitor 15Lys-bis-netropsin, a potentiating effect is observed, which allows decreasing the concentrations of the combined compounds by 4 times or more while maintaining antiviral activity. LAS-131 interacted additively with foscarnet, ribavirin, and α-interferon. Conclusion. Combinations of LAS-131 with known antiviral agents have been established, providing synergistic and additive effects of interaction against HSV-1.
Introduction. The unfavorable epidemiological situation with viral tick-borne infections can be characterized not only by an increase in the incidence of «classical», well-known diseases, but also by the discovery of new pathogens, the role of which remains poorly understood. Yezo virus (YEZV) belongs to the group of recently discovered tick-borne nairoviruses. YEZV circulation is characteristic of Japan, China, and a number of regions in Russia (Primorsky, Khabarovsk, and Zabaykalsky Krais; Tomsk Oblast). The aim of the study was to screen and characterize the molecular genetics of YEZV isolated from ticks in the Amur region. Materials and methods. In the study, 704 individual tick samples (463 I. persulcatus ticks and 241 H. concinna ticks) collected from vegetation in 15 locations in 5 districts of the Amur Region were analyzed for the presence of YEZV RNA. Full-length genomic sequencing of the identified YEZV genetic variant was performed by preliminary enrichment of YEZV cDNA using multiplex PCR with a primer panel developed by us. Results. The YEZV infection rate in the studied sample of I. persulcatus ticks was 0.2% (1/463; 95% CI: 0.1–1.2). Conclusion. The results of this study expand our understanding of the spread of YEZV in Russia. Up-to-date information on the circulation and genetic diversity of nairoviruses that pose a potential threat to humans and animals contributes to the regulation and adjustment of preventive and anti-epidemic measures, as well as the implementation of adequate region-oriented laboratory diagnostics of IPK in the Far East, and especially in areas bordering China.
Introduction. Secondary bacterial pneumonias are complications responsible for most fatalities following influenza infection, and antiviral drugs are used to prevent their development. The aim of the study is to evaluate the efficacy of tilorone and its combination with antibacterial agents in a murine model of secondary bacterial pneumonia caused by Staphylococcus aureus after influenza infection. Materials and methods. BALB/c mice were infected with influenza virus A/California/04/2009 (pdm H1N1 2009) virus, followed by S. aureus infection four days later. Treatments included the interferon inducer tilorone, comparator oseltamivir, antibacterial agents cefuroxime and amoxicillin, or combinations of antivirals with antibiotics. Efficacy was assessed by increased survival, reduced weight loss, and inhibition of pathogen proliferation in the lungs. Results. The efficacy of tilorone, as indicated by increased survival, reduced weight loss, and decreased pathogen load in the lungs, in a mouse model of secondary bacterial pneumonia following influenza infection, increased with reducing viral dose, and intraperitoneal administration of the drug was more effective than oral administration. The combination of tilorone with the antibiotic cefuroxime, to which S. aureus was sensitive, was more effective than either agent alone and completely protected animals from death and from viral and bacterial proliferation in the lungs. In contrast, the combination with amoxicillin, to which S. aureus was resistant, had no effect on disease outcome. Conclusion. The efficacy of tilorone in this model depended on viral dose and drug administration route. Combining tilorone with cefuroxime was more effective than monotherapy.
Introduction. The high economic losses and the lack of effective and safe vaccines against African swine fever (ASF) indicate the need for further in-depth studies of the virus genome, its changes and the circulation of genetic lineages. Whole genome sequencing of virus isolates is best suited for this purpose. The aim of the study. Whole-genome analysis of African swine fever virus (ASFV) isolates obtained in the Lipetsk, Penza and Tambov regions in 2016–2021 and identification of additional diversity markers within the genetic lineage. Materials and methods. Domestic pig tissue samples were analyzed using whole-genome sequencing and Sanger sequencing. The following programs were used for sequence assembly: CLC Genomics Workbench 22, Trimmomatic v. 0.39, SPAdes v. 4.2.0, BWA-MEM v. 0.7.17-r1188 and bcftools v.1. 22. The phylogenetic tree was constructed in MEGA11 based on the alignment in MAFFT v. 7.526 with 67 genomes from GenBank. Results. Based on the presence of MGF 360-10L III polymorphism, the analyzed isolates belong to the CVR-V variant of the Russia genetic lineage of the Georgia 2007 clade. Based on the order of formation of MGF 360-10L III and CVR-V, any sequences carrying CVR-V belong to the same genetic lineage. A 12-nucleotide insertion CAGTCTATAAGA was detected, forming a tandem duplication in IGR MGF 360-13L – MGF 360-14L, and polymorphisms in IGR C62L – C962R and in genes D1133L and Q706L were proposed as having phylogenetic potential for differentiation ASFV strains in the central regions of Russia. Conclusion. The proposed new potential diversity markers have a resolving power for ASFV strains from Central Russia.
Introduction. Nef provides high level of HIV-1 replication due to synergy of its multiple functions and is an important factor in the pathogenesis of HIV infection. Nef is considered as a target for development of therapeutic agents. Mutations of drug resistance to dolutegravir can occur in Nef protein. Natural amino acid substitutions in Nef protein have been associated with the degree of progression of HIV infection, development of neurodegenerative and cardiovascular diseases in patients. The aim of the study is to investigate Nef genetic diversity in HIV-1 variants circulating in Russia and in Moscow region. Materials and methods. Total 216 Nef sequences obtained from whole blood samples of patients and 77 sequences downloaded from the Los Alamos International Database were analyzed. Consensus sequences of Nef sub-subtype A6, subtype B, CRF02_AG, CRF63_02A6, CRF133_A6B, and the reference sequence NL4-3 were compared. Genetic diversity of Nef sub-subtype A6 (Nef-A6) in patients with different stages of the disease was assessed. The presence of dolutegravir-associated drug resistance mutations in the Nef protein in HIV-1 variants circulating in Russia was also investigated. Results. Differences in the spatial structures in consensus sequences of the studied HIV-1 variants were determined. It was shown that the conservatism of Nef-A6 in groups of patients with later stages of the disease was significantly higher. No mutations of drug resistance to dolutegravir were detected. Conclusion. The differences in Nef sequences of HIV-1 variants circulating in Russia could affect the functional properties of the protein and could be taken into account in creating Nef-based therapies in the future. Obtained results indicate that there is no risk of resistance to dolutegravir associated with – mutations in the Nef protein. It outlines possible directions for further research into the genetic diversity of Nef.
Introduction. Parechoviruses of the Parechovirus ahumpari (PeV-A) species, pathogenic to humans, are widespread and genetically diverse infectious agents. Infections caused by these viruses are characterized by a wide variety of clinical manifestations ranging from mild intestinal or respiratory diseases to severe CNS lesions. The high-risk group for the disease are newborns and infants. PeV-A species are classified in 19 types that have a varying distribution in different territories. In Russia, the type composition of territorial parechovirus populations has not been sufficiently studied, which determines the relevance of monitoring the circulation of these viruses using genotyping. The aim of the study was to identify and investigate the genetic diversity of parechoviruses that circulated in Nizhny Novgorod in the period 2021–2024. Materials and methods. 5,073 stool samples from children hospitalized in an infectious hospital with a diagnosis of acute gastroenteritis were examined for the presence of human parechoviruses. The detection of parechoviruses was carried out by RT-PCR. Viral types were determined by Sanger sequencing of VP1 genome fragment. The nucleotide sequences were analyzed using MEGA X and Beast v1.8.4 software. Results. Parechoviruses were detected in children aged 3 months to 17 years with a frequency of 0.06–2.08% in different years, an average of 1.46 ± 0.16%. Viral type has been identified for 52 strains. Six types of PeV-A parechoviruses have been identified. The PeV-A1 was a predominant type (80.4%). Types PeV-A2 to PeV-A6 have been found in isolated cases. Heterogeneity of the PeV-A1 population in Nizhny Novgorod was represented by virus genotypes 1A and 1B, with an absolute predominance of genotype 1B, which included 16 genetic variants. Conclusion. The data obtained expand information on the type and genetic diversity of pathogenic for humans parechoviruses circulating among the population of central Russia (based the example of the Nizhny Novgorod region).
