[Molecular epidemiological analysis of SARS-CoV-2 genovariants in Moscow and Moscow region].

INTRODUCTION: SARS-CoV-2, a severe acute respiratory illness virus that emerged in China in late 2019, continues to spread rapidly around the world, accumulating mutations and thus causing serious concern. Five virus variants of concern are currently known: Alpha (lineage B.1.1.7), Beta (lineage B.1.351), Gamma (lineage P.1), Delta (lineage B.1.617.2), and Omicron (lineage B.1.1.529). In this study, we conducted a molecular epidemiological analysis of the most prevalent genovariants in Moscow and the region. The aim of the study is to estimate the distribution of various variants of SARS-CoV-2 in Moscow city and the Moscow Region. MATERIALS AND METHODS: 227 SARS-CoV-2 sequences were used for analysis. Isolation of the SARS-CoV-2 virus was performed on Vero E6 cell culture. Sequencing was performed by the Sanger method. Bioinformatic analysis was carried out using software packages: MAFFT, IQ-TREE v1.6.12, jModelTest 2.1.7, Nextstrain, Auspice v2.34. RESULTS: As a result of phylogenetic analysis, we have identified the main variants of the virus circulating in Russia that have been of concern throughout the existence of the pandemic, namely: variant B.1.1.7, which accounted for 30% (9/30), AY.122, which accounted for 16.7% (5/30), BA.1.1 with 20% (6/30) and B.1.1 with 33.3% (10/30). When examining Moscow samples for the presence of mutations in SARS-CoV-2 structural proteins of different genovariants, a significant percentage of the most common substitutions was recorded: S protein D614G (86.7%), P681H/R (63.3%), E protein T9I (20.0%); M protein I82T (30.0%), D3G (20.0%), Q19E (20.0%) and finally N protein R203K/M (90.0%), G204R/P (73.3 %). CONCLUSION: The study of the frequency and impact of mutations, as well as the analysis of the predominant variants of the virus are important for the development and improvement of vaccines for the prevention of COVID-19. Therefore, ongoing molecular epidemiological studies are needed, as these data provide important information about changes in the genome of circulating SARS-CoV-2 variants.

[Antiviral properties of synthetic histidine derivatives containing membranotropic volumetrical carbocycles in their molecule against SARS-CoV-2 virus in vitro].

INTRODUCTION: Currently, low molecular-weight compounds are being developed as potential inhibitors of CoVs replication, targeting various stages of the replication cycle, such as major protease inhibitors and nucleoside analogs. Viroporins can be alternative protein targets. The aim of this study is to identify antiviral properties of histidine derivatives with cage substituents in relation to pandemic strain SARS-CoV-2 in vitro. MATERIALS AND METHODS: Combination of histidine with aminoadamantane and boron cluster anion [B10H10]2 (compounds IIV) was carried out by classical peptide synthesis. Compound were identified by modern physicochemical methods. Antiviral properties were studied in vitro on a monolayer of Vero E6 cells infected with SARS-CoV-2 (alpha strain) with simultaneous administration of compounds and virus. RESULTS: Derivatives of amino acid histidine with carbocycles and boron cluster were synthesized and their antiviral activity against SARS-CoV-2 was studied in vitro. Histidine derivatives with carbocycles and [B10H10]2 have the ability to suppress virus replication. The solubility of substances in aqueous media can be increased due to formation of hydrochloride or sodium salt. DISCUSSION: 2HCl*H-His-Rim (I) showed some effect of suppressing replication of SARS-CoV-2 at a viral load of 100 doses and concentration 31.2 g/ml. This is explained by the weakly basic properties of compound I. CONCLUSION: The presented synthetic compounds showed moderate antiviral activity against SARS-CoV-2. The obtained compounds can be used as model structures for creating new direct-acting drugs against modern strains of coronaviruses.

Radiation Inactivation of Coronavirus Infection Pathogen by the Example of Transmissible Gastroenteritis Virus.

In recent years, members of the Coronaviridae family have caused outbreaks of respiratory diseases (MERS, SARS, and COVID-19). At the same time, the potential of radiation-induced inactivation of this group of viruses have been little studied, although radiation technologies can be widely used both in the processing of personal protective equipment and in the sterilization of vaccines. In the present work, the effect of 10 MeV electron beams and 7.6 MeV bremsstrahlung on the coronavirus infection pathogen (transmissible gastroenteritis virus) has been studied in vitro. In the given experimental conditions, irradiation with photons turned out to be more effective. The virus-containing suspension frozen at -86°C was the most resistant to radiation: the dose required for complete inactivation of the virus in this case was from 15 kGy, while for the liquid suspension and lyophilized form the sterilizing dose was from 10 kGy. At lower radiation doses for all samples during passaging in cell culture, residual infectious activity of the virus was observed. These differences in the efficiency of inactivation of liquid and frozen virus-containing samples indicate a significant contribution of the direct effect of radiation.

Antiviral activity of benzydamine hydrochloride against SARS-CoV-2 in vitro model

Due to the emergence of a new coronavirus infection COVID-19, scientists around the world are actively working on a vaccine against the SARS-CoV-2 coronavirus. At the same time, it is possible that existing medications can help in the fight against this disease. The local antiseptic drug benzidamine hydrochloride in the early stages of illness can prevent the virus from entering the lower respiratory tract and potentially reduce the severe illness associated with pneumonia and, as a result, reduce COVID-19-related hospitalizations, which can significantly reduce the burden on the health care system. The aim: to evaluate the antiviral activity of benzidamine hydrochloride against SARS-CoV-2 in vitro. Material and methods. Antiviral properties of benzidamine hydrochloride were studied in vitro in non-toxic concentrations on monolayer of Vero-E6 cells infected with pandemic strain of SARS-CoV-2 coronavirus in treatment and prophylactic scheme of the compound and virus administration. Results. Benzidamine hydrochloride has antiviral activity (15,0 mcg/ml), the efficiency of its antiviral action is directly proportional to the concentration of the substance. Conclusions. Taking into account very limited range of antiviral drugs with direct action on SARS-CoV-2 virus, the studied preparation can be used in complex therapy at early stages of the disease, which can prevent virus penetration into lower respiratory tract and potentially reduce the number of complications. © 2021, Numikom. All rights reserved.