Problems of Virology

Acute respiratory viral infections (ARVI) are one of the most significant infections affecting the breeding of monkeys, especially among imported and captive primates. Respiratory diseases are also an important cause of morbidity and mortality in wild populations, and most of these infections can affect humans. Many anthropoid species, including apes, are susceptible to ARVI. Outbreaks of spontaneous respiratory infections have been described in many zoos and primatological centers around the world. Moreover, the study of spontaneous and experimental infection in laboratory primates provides an invaluable source of information on the biology and pathogenesis of ARVI and remains an indispensable tool for testing vaccines and drugs. The aim of this literature review was to summarize and analyze published data on the circulation of ARVI causative agents (parainfluenza viruses, adenoviruses, respiratory syncytial virus, influenza viruses, rhinoviruses, coronaviruses, metapneumoviruses, bocaviruses) among wild and captive primates, as well as the results of experimental modeling these infections in monkeys.

Introduction. Predisposition to different courses of the infectious process is largely associated with the polymorphisms in human genome, especially in genes encoding proteins of the immune system. In the early stages of influenza infection such components of innate immunity as interferons I (α/β) and III (λ) type play a significant role in limiting virus replication.

The aim of the work was to investigate associations of single nucleotide polymorphism in IFNL3 (rs8099917 T/G) and IFNL4 (rs12979860 C/T) genes with different course of influenza, and identify genetic markers of influenza complicated by community-acquired pneumonia. The genes noted above affect the production of interferon-λ3, which is involved in restriction of the viral replication.

Materials and methods. Samples from 456 patients with mild (n = 150), moderate (n = 173), and severe (n = 133) influenza were studied. The viral RNA was detected by reverse transcription and polymerase chain reaction (RT-PCR). Polymorphisms in IFNL3 (rs8099917 T/G) and IFNL4 (rs12979860 C/T) genes was detected by PCR. Statistical analysis was performed using SNPStats software.

Results. Patients with the C/T or T/T genotype of IFNL4 gene (rs12979860 C/T) were more likely to have pneumonia than those with the C/C genotype (OR 2.47 (1.31–4.63); p = 0.0044; q = 0.0059). The presence of one T allele increased the risk of developing pneumonia (OR 2.02 (1.05–4.02); p = 0.006; q = 0.008). In the presence of the T/T genotype, the risk increased more than twofold: OR 2.14 (1.31–3.48). Analysis of the SNP of IFNL3 gene (rs8099917 T/G) revealed a weak association of the G allele with pneumonia (OR 1.86 (1.04–3.31); p = 0.03; q = 0.045).

Conclusion. Genetic markers of increased risk of community-acquired pneumonia in influenza include the presence of the T allele in IFNL4 gene (rs12979860 C/T) and, to a lesser extent, the G allele in IFNL3 gene (rs8099917 T/G). Patients carrying these alleles have an increased risk of developing pneumonia, especially in old age.

Introduction. Monitoring and research on arthropod-borne microorganisms is important. Recently, with the development of next-generation sequencing methods, many previously unknown viruses have been identified in insects.

Aim of the study. Isolation of viruses from mosquitoes sampled in the Republic of Sakha (Yakutia), followed by the study of a new for Russia negevirus isolated from mosquitoes of the species Ochlerotatus caspius, including determination of its complete nucleotide sequence, phylogenetic and virological characteristics.

Materials and methods. Dezidougou virus isolation was performed on C6/36 (Aedes albopictus) cell culture. Electron microscopy was performed using a JEM 1400 electron microscope. Nucleotide sequence screening was performed by NGS on a high-throughput sequencer MiSeq, Illumina (USA). Full genome nucleotide sequence was determined by Sanger sequencing. Phylogenetic analysis was performed using GenBank database, using Vector NTI Advance 11 and MEGA 11 programs.

Results. The virus isolated from mosquitoes replicated efficiently in C6/36 cells, causing their death. However, it did not replicate in the mammalian cell cultures used. The isolated virus did not cause pathologic manifestations in suckling mice when infected intracerebrally. Electron microscopic examination of the purified virus-containing suspension showed the presence of spherical viral particles with a diameter of 45‒55 nm. The results of full genome sequencing identified it as belonging to Dezidougou virus, first isolated in Côte d’Ivoire. The nucleotide sequence of the genome of Yakutsk 2023 strain of Dezidougou virus was deposited in GenBank (PP975071.1).

Conclusion. Dezidougou virus of genus Negevirus was isolated and characterized for the first time in the Russian Federation. Further studies on the prevalence of negeviruses, their virological features, potential importance for public health and their impact on vector competence of vectors are important and promising.

Introduction. Influenza is an acute respiratory viral infectious disease caused by the influenza viruses. Current preventive and therapeutic approaches are of great anti-epidemic importance, but there are a number of problems, such as the rapid emergence of resistant strains, the lack of cross-immunity and the effectiveness of vaccines. One of the approaches to the development of anti-influenza agents is the use of RNA interference and small interfering RNAs complementary to the mRNA target of viral and cellular genes.

Aim ‒ to evaluate the prophylactic anti-influenza effect of siRNAs directed to the cellular genes NXF1, PRPS1 and NAA10 in an in vitro model.

Materials and methods. Antigenic variants of influenza A virus: A/California/7/09 (H1N1), A/WSN/33 (H1N1) and A/Brisbane/59/07 (H1N1); cell cultures A549 and MDCK. The study was performed using molecular genetic (transfection, NC isolation, RT-PCR-RV) and virological (cell culture infection, titration by visual CPE, viral titer assessment using the Ramakrishnan method) methods.

Results. It was shown that siRNAs targeting the cellular genes NXF1, PRPS1 and NAA10, when used prophylactically in cell culture at a concentration of 0.25 μg per well, during infection with influenza virus strains A/California/7/09 (H1N1), A/WSN/33 (H1N1) and A/Brisbane/59/07 (H1N1) at a multiplicity of infection of 0.01, reduced viral replication to a level of 220 TCID₅₀ per 1 ml of cell medium, whereas in control untreated cells the viral yield was ~106 TCID₅₀ per 1 ml of medium.

Conclusions. Reproduction of influenza A viruses directly depends on the protein products of the NXF1, PRPS1, and NAA10 genes. Reduced expression of these genes disrupts the life cycle and activity of influenza viruses. Such an approach can potentially be studied and used for closely and distantly related representatives of other virus families.

Introduction. Monitoring of hemorrhagic fever with renal syndrome (HFRS) pathogens in the Republic of Belarus is necessary and relevant, since the number of HFRS cases in the population has increased in recent years, and genetic characteristics of the pathogens remain unidentified.

Aim of the study. Identification of orthohantaviruses circulating in the territory of the Republic of Belarus and defining of their genetic characteristics.

Materials and methods. Screening of 613 samples from small mammals caught in the territory of the Republic of Belarus was carried out by the real time PCR method using the test system «Belar-GLPS-PCR/RV». Positive samples were sequenced by the Sanger method. Comparative and phylogenetic analysis was carried out using the MegAlign programs from the Lasergene package (DNASTAR, USA) and MEGA 11.

Results. The primary screening yielded 32 PCR-positive samples (5.2%), of which 24 belonged to Puumala virus (PUUV) and 8 to Dobrava-Belgrade virus (DOBV). Three nucleotide sequences of the M-segment region of PUUV, two sequences of the 291-base pair (bp) M-segment region and one sequence of the 348-bp S-segment region of DOBV were sequenced. Comparative and phylogenetic analysis showed that the identified PUUV sequences belong to the Russian genetic lineage, to the same sublineage as the strains common in the Moscow and Kursk regions. The identified DOBV ssequences demonstrated the closest relationship to the strains from the central region of the European part of Russia.

Conclusion. The results of molecular biological analysis showed that PUUV circulates in the territory of the Republic of Belarus and is widespread. At the same time, DOBV was detected in four regions of the republic, which indicates an expansion of the range of this HFRS pathogen. In the Republic of Belarus, nucleotide sequences of orthohantaviruses were obtained for the first time and their molecular genetic analysis was carried out.