Voprosy virusologii最新文献

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).

Introduction: The Kurkino and Sochi viruses of species Orthohantavirus dobravaense (ODOB) are among the pathogens that cause hemorrhagic fever with renal syndrome in the European part of Russia. However, the current literature provides limited data on the distribution of genetic variants of the ODOB in Russia. The aim is to identify ODOB in several regions of Volga, Central and Ural Federal districts of the Russian Federation and analyze their genome.

Materials and methods: Total RNA was isolated from lung tissue samples of striped field mouse (Apodemus agrarius) and yellow-necked mouse (A. flavicollis) captured in a number of areas of the Volga Federal District and neighboring regions in 2015-2023. Orthohantavirus RNA was detected by RT-PCR using specific primers to ODOB. The PCR amplification products were separated in agarose gel, purified, and subjected to Sanger sequencing. Comparative and phylogenetic analyses were performed for the sequenced genome fragments.

Results: Orthohantavirus RNA was detected in one sample of A. flavicollis from the Ulyanovsk region. Based on the analysis of the nucleotide sequences of the sequenced PCR products, it was found that the highest values of similarity were obtained when comparing the identified strain with the reference Kurkino virus from the Tula region. The data from the phylogenetic analysis of the sequenced fragment of the S and M segments allowed us to establish that the identified isolate is closely related to the Kurkino virus found earlier in A. agrarius in the Tula region. Thus, the detected isolate was identified as variant of Kurkino virus, which is also widespread in the central regions of Russia, Wetern Siberia and close related to genome variants that are distributed in Central Europian countries.

Conclusions: It is proved for the first time that: 1) the range of Orthohantavirus dobravaense (Kurkino virus) extends to a part of the territory of the Volga Federal District; 2) Orthohantavirus dobravaense (Kurkino virus) and Orthohantavirus puumalaense (Puumala virus) are co-circulating in the Ulyanovsk region.

Severe disease progression, including secondary bacterial infections and sepsis, can occur both during initial infection with the varicella-zoster virus (VZV) and its reactivation in the form of herpes zoster. This remains a fairly common problem. However, in most cases, the disease proceeds without complications. In Russia and abroad, varicella is among the most common infectious causes of central nervous system involvement. The most frequent serious complications are skin lesions and associated bacterial infections. The exact causes of these conditions are still not fully understood. Therefore, there is ongoing debate about the possible role of certain viral clades or genetic polymorphisms in patients. This review describes inter-clade differences among viral genotypes, their origins, ability to recombine, clinical cases of infection caused by representatives of different clades, data on their circulation, mechanisms of immune evasion and human candidate genes potentially associated with VZV-related complications. The literature search was conducted using PubMed, Google Scholar, CyberLeninka, and the eLIBRARY.

Introduction: Differentiation of vaccine strains and field isolates of bovine type 1 herpesvirus Varicellovirus bovinealpha1 is an urgent task to improve the quality of diagnosis of infectious bovine rhinotracheitis (IBR). There are several approaches to solve this problem. The most successful methods are those proposed by R.W. Fulton and S.K. Chothe in 2013 and 2018, respectively. The aim of the study is to test the methods proposed by R.W. Fulton and S.K. Chothe to study the possibility of their optimization and implementation in routine laboratory diagnostics of IBR in Russia.

Materials and methods: 4 vaccine strains and 6 field isolates of the IBR virus were studied using PCR-based algorithms by R.W. Fulton and S.K. Chothe to determine the presence of single nucleotide substitutions at 11 control points of the virus genome in comparison with the nucleotide sequence of the reference strain Cooper JX898220.

Results: Both methods confirmed that the domestic strains of the IBR virus used for the production of inactivated vaccines originate from field isolates of the virus. Both the reference and modern epizootic isolates obtained by us and our colleagues at different times in Russia are epizootic strains that have no direct connection with the large-scale use of foreign vaccines, including live ones, both among our own indigenous livestock and among animals imported from abroad. None of the methods we tested allows us to distinguish between Varicellovirus bovinealpha1 and Varicellovirus bovinealpha5.

Conclusion: The methods proposed by R.W. Fulton (2013) and S.K. Chothe (2018) can be used to differentiate vaccine strains and field isolates of IBR virus only after our recommended preliminary differentiation of BoHV of types 1 and 5.

Introduction: Human immunodeficiency virus (HIV) and hepatitis B (HBV) and C (HCV) viruses remain among the most dangerous bloodborne pathogens, posing a significant global public health threat. The aim of our work was to assess the prevalence of HIV, HBV, and HCV markers among dental patients and provide a molecular genetic characterization of the identified pathogens.

Materials and methods: We analyzed 497 plasma samples from individuals who sought dental care in St. Petersburg for serological and molecular markers of target infections. Viral genome fragments were sequenced and analyzed when molecular markers were detected.

Results: Anti-HCV were detected in 3.8% (19/497) of participants, with HCV RNA in 1% (5/497). HIV Ag/Ab was found in 1.2% (6/497), with two cases (0.4%, 2/497) confirmed by immunoblot; no HIV RNA was detected. HBsAg prevalence was 2.4% (12/497), with anti-HBs in 32.0% (159/497) and anti-HBc in 25.6% (127/497) of participants. Significant age-related trends were observed: anti-HBs predominated in younger groups while anti-HBc was more frequent in older individuals. HBV DNA was detected in 3.8% (19/497) of cases, including 1.8% (9/497) HBsAg-negative infections. Predominant in the Russian Federation viral genotypes were identified (HCV: 1b, 2a, 3a; HBV: D1, D2, D3). One HCV isolate carried mutations associated with resistance to dasabuvir, sofosbuvir, and voxilaprevir. Multiple HBV isolates harbored concurrent mutations causing diagnostic escape (HBsAg-negative variants), reduced vaccine efficacy, viral reactivation, and disease progression.

Conclusions: The study reveals high viral hepatitis prevalence among dental patients. Detection of drug-resistant HCV variants and immune-evading HBV strains underscores the need for enhanced molecular surveillance, improved diagnostic protocols, and strengthened infection control measures.

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: There are three antigenic subtypes of tick-borne encephalitis virus (TBEV): the European, Far Eastern and Siberian subtypes. The article discusses the topic of cross-protective neutralizing antibodies against different subtypes of TBEV. Objective ‒ the study of the immune response after vaccination against TBE in recipients immunized with Russian-made vaccines in relation to Siberian, Far Eastern, and European subtypes.

Materials and methods: 100 serum samples obtained from recipients vaccinated against TBE. ELISA reagent kit was used to detect IgG antibodies to TBEV. The neutralization reaction on cell culture was used to analyze the titer of neutralizing antibodies. The following TBEV strains were used: Sofyin; Vasilchenko; Absettarov; Ekb_1887_1.

Results: A decrease in the levels of neutralizing antibodies against heterologous strains compared to the vaccine strain was observed: for the Siberian strains Ekb_1887_1 and the Vasilchenko, a decrease was of 3.9 and 2.4 times, respectively; for the European strain, a 4.9-fold decrease compared to vaccine strain was observed. In case when IgG antibody titers were below 1 : 500, the titers of antibodies to TBEV strains heterologous to the vaccine did not exceed the minimum detectable value of 1 : 10. For individuals with IgG antibody titers below 1 : 100, antibodies to Sofyin strain were not detected. Individuals with reduced titers of virus-specific antibodies more often had deviations from the recommended vaccination schedule.

Conclusion: Given the widespread distribution and genetic variability of the Siberian subtype, as well as the limited cross-neutralization capabilities of existing vaccines, the task of developing a combined vaccine that includes antigens of several virus subtypes seems relevant.

Herpes simplex virus type 1 (HSV-1), newly named as Simplexvirus humanalpha1 is one of the most common pathogens in the human population, which can cause severe disease, often with fatal outcomes. Diagnostic methods currently in use are specific and sensitive, but time-consuming, require expensive laboratory equipment and highly qualified personnel. Existing therapeutic agents have a number of significant drawbacks. To successfully treat and prevent the spread of the infection, new rapid, easy-to-use, and highly sensitive diagnostic tools and effective therapeutic agents are required. One approach to achieve this goal is CRISPR-based technology. This review analyzes information obtained from a literature search in the Scopus, Web of Science and MedLine databases on the topics «HSV-1, structure, distribution, life cycle», «new methods for molecular diagnosis of HSV-1-infection», «classification of CRISPR-Cas systems», «nucleic acid amplification methods», «CRISPR-Cas effector proteins», «application of CRISPR-Cas systems in molecular diagnostics of HSV-1-infection», «application of CRISPR-Cas systems in therapy of HSV-1-infection». New approaches of CRISPR using effector proteins Cas12 and Cas13 in the diagnosis of HSV-1 infections are reviewed. The article discusses the progress in the development of CRISPR-Cas-based therapies against HSV-1-infection in vitro and in vivo. CRISPR gene therapy in vivo has a great clinical potential, but its safety and efficacy require further investigation. An analysis of the available data suggests that CRISPR-based technologies offer promising prospects for expanding the arsenal of diagnostic tools and antiviral drugs in the context of current and future outbreaks of viral diseases.

Purpose: Mpox cases were previously common in children; recent outbreaks of clade II have mostly affected young adults. Therefore, this study examines the knowledge, attitudes, and seroprevalence of the Mpox virus among consenting participants in Ibadan.

Materials and methods: Eligible individuals were those who voluntarily participated in the study and met the inclusion criteria specified for the study. A cross-sectional survey was conducted involving 94 respondents, investigating socio-demographic factors, awareness levels, attitudes toward prevention, and infection rates. The anti-Mpox virus IgG antibody was detected quantitatively using the Enzyme-Linked Immunosorbent Assay (ELISA) technique. The data were then analyzed using the χ² test, while the antibody quantification was displayed with a Box and Whisker plot; statistical significance was determined at p < 0.05.

Results: The majority of respondents were female (66.7%) and aged 58 years and above (20.0%). Most had tertiary (40.0%) and secondary education (34.4%). Awareness of the Mpox was moderate, with 61.1% having heard of the virus, primarily through news (20.0%) and healthcare workers (18.9%). However, knowledge gaps were evident: only 38.9% recognized symptoms, and 40.0% understood modes of transmission. Attitudes towards prevention were generally positive; 60.0% believed Mpox could be prevented, and 73.3% were willing to take a vaccine. Still, readiness to engage in screening was low; 81.1% had never been tested, and 58.9% were unaware of local test availability. Regarding seroprevalence, females showed a significantly higher infection rate (27.4%) than males (9.6%) (χ² = 3.854, p = 0.050). Age-wise, the highest infection rates occurred in those < 18 years (61.5%) and 53-57 years (66.6%) (χ² = 30.817, p = 0.000), indicating significant age-related differences.

Conclusion: The findings highlight the need for targeted public health education, increased test access, and focused intervention strategies to improve Mpox virus prevention and control, especially among vulnerable age groups and under-informed populations.

Introduction: The antiviral action of a number of drugs is associated with their modification of the lipid membrane of viruses. One of the possible mechanisms of such modification of the viral membrane is the extraction of cholesterol from the membranes of virions.

Objective of the study: A method has been developed for determining the infectious and hemagglutinating titer of avian influenza virus by changing the microviscosity of the viral membrane after incubation with phospholipid modifiers, using cholesterol-free liposomes consisting of phosphatidylcholine and phosphatidylethanolamine in a molar ratio of 1 : 2 for 48 hours as an example.

Materials and methods: The extraction process was confirmed by two methods: gel filtration with radioactively labeled liposomes and virions, and by changing the polarization value of the fluorescent probe 1-anilinonaphthalene-8-sulfonate anion (8-ANS) in the viral membrane.

Results: A correlation was found between the change in infectious and hemagglutinating titer and the microviscosity of the viral membrane.

Conclusion: In this regard, it seems possible to use this dependence to determine the infectious and hemagglutinating activity of the influenza virus within one serotype in clinical laboratory diagnostics, using various fluorescent probes. It should be noted that not only liposomes of a certain composition can be used as lipophilic modifiers of the viral membrane, but also such compounds as ethylene glycol, erythritol, glycerol.