Molecular-genetic analysis of epidemical strains of influenza a virus based on the neuraminidase and M2 protein gene sequence

The results of a molecular-genetic analysis of epidemical strains of influenza A virus isolated in Russia from 1995 to 2007 are described. The analysis based on the genes sequences of neuraminidase (NA) and M2 protein of influenza A virus was performed. 15 strains of subtype A(H3N2) and 17 strains of subtype A(H1N1) were analyzed for the detection of mutations in the genome virus. The analysis of amino acid sequences of M2 protein of the all remantadin resistant strains demonstrated the substitution S31N as the basic resistant marker. Additional mutations in M2 and NA proteins were detected for both subtypes of the virus. Identified mutations, together with an S31N substitution, could be classified as novel markers for identification of remantadin-resistant strains. The sequence's analysis of NA from both subtypes of the influenza virus possessed no known mutations to cause a resistance to neuraminidase inhibitors, which indicates the susceptibility of analyzed strains to NA inhibitors. © 2008 Allerton Press, Inc

Molecular-genetic analysis of epidemical strains of influenza a virus based on the neuraminidase and M2 protein gene sequence

The results of a molecular-genetic analysis of epidemical strains of influenza A virus isolated in Russia from 1995 to 2007 are described. The analysis based on the genes sequences of neuraminidase (NA) and M2 protein of influenza A virus was performed. 15 strains of subtype A(H3N2) and 17 strains of subtype A(H1N1) were analyzed for the detection of mutations in the genome virus. The analysis of amino acid sequences of M2 protein of the all remantadin resistant strains demonstrated the substitution S31N as the basic resistant marker. Additional mutations in M2 and NA proteins were detected for both subtypes of the virus. Identified mutations, together with an S31N substitution, could be classified as novel markers for identification of remantadin-resistant strains. The sequence's analysis of NA from both subtypes of the influenza virus possessed no known mutations to cause a resistance to neuraminidase inhibitors, which indicates the susceptibility of analyzed strains to NA inhibitors. © 2008 Allerton Press, Inc

ПРОИЗВОДНЫЕ АДАМАНТАНА, СПОСОБНЫЕ ИНГИБИРОВАТЬ РЕПРОДУКЦИЮ РЕЗИСТЕНТНОГО К РИМАНТАДИНУ ШТАММА ВИРУСА ГРИППА A(H1N1)PDM09 (INFLUENZA A VIRUS, ALPHAINFLUENZAVIRUS, ORTHOMYXOVIRIDAE)

Introduction. Adamantanthane-type drugs such as rimantadine and amantadine have long been used to treat diseases caused by influenza A virus. However, as a result of the mutations, influenza viruses have become resistant to aminoadamantans. The target for these drugs was the protein channel M2. Influenza A virus M2 viroporin in the protein shell forms fairly specific ion channels with a diameter of about 11 Å, specializing in transporting protons inside the viral particle (virion). Restoration of the antiviral properties of adamantanthane-type drugs consists in the selection of advanced functional groups bound by the carbocycle to find new sites of binding to the protein target M2. The purpose of the study is to identify the antiviral properties of new adamantanum derivatives to the pandemic strain of influenza A virus in vitro. Material and methods. Compounds of aminoadamantans with amino acids and other organic molecules were obtained by classical peptide synthesis methods. The structure of the compound was tested by means of physical and chemical methods. Antiviral properties of synthetic compounds were studied in vitro on monolayer MDCK cells infected with pandemic strain of influenza A/California/07/2009 virus in two schemes of administration of investigated compounds and virus. Results. The reference strain of the influenza virus A/California/07/2009(H1N1) was sensitive to the compounds under test in varying degrees. The antiviral activity of the compounds was expressed in a 50% inhibitory concentration (IC50) ranging from 0.5 to 2.5 mkM, which is generally a good indicator for the Rimantadine/Amantadine resistant strain. Discussion. The values of the IC50 for compounds introduced two hours before contact with the virus were slightly higher than those for single-moment introduction of the substance and virus. The effect of increasing the inhibitory concentration in the prophylactic scheme of compounds was valid for all compounds of the experiment. Conclusion. The presented synthetic compounds are active against the variant of influenza A virus resistant to Rimantadine and Amantadine preparations. The obtained compounds can be used as model structures for creation of a new drug of direct action against advanced strains of influenza A virus.Введение. Соединения адамантанового ряда, такие как римантадин и амантадин, долгое время применяли для лечения заболеваний, вызванных вирусом гриппа А. Однако в результате возникших мутаций вирусы гриппа приобрели резистентность к аминоадамантанам. Мишенью для этих препаратов служил белковый канал М2. Виропорин М2 в белковой оболочке вируса гриппа А образует достаточно специфичные ионные каналы диаметром около 11 Å, специализирующиеся на транспорте ионов водорода внутрь вирусной частицы (вириона). Восстановление противовирусных свойств препаратов адамантанового ряда заключается в подборе дополнительных функциональных групп, связанных карбоциклом, для поиска новых сайтов связывания с белком мишенью М2. Цель исследования - выявление противовирусных свойств адамантановых производных в отношении пандемического штамма вируса гриппа А in vitro. Материал и методы. Соединения аминоадамантанов с аминокислотами и другими органическими молекулами были получены методами классического пептидного синтеза. Структура соединения подтверждена современными физико-химическими методами. Противовирусные свойства синтетических соединений были изучены in vitro на монослое клеток MDCK, инфицированных пандемическим штаммом вируса гриппа А/California/07/2009 в двух схемах введения исследуемых соединений и вируса. Результаты. Эталонный штамм вируса гриппа A/California/07/2009(H1N1) был в разной мере чувствителен к тестируемым соединениям. Противовирусную активность соединений выражали в виде 50% ингибирующей дозы (ИД50), которая составила от 0,5 до 2,5 мкМ, что в целом неплохой показатель в отношении штамма, резистентного к римантадину/амантадину. Обсуждение. ИД50 для соединений, вносимых за 2 ч до контакта с вирусом, была несколько выше, чем при одномоментном внесении вещества и вируса. Эффект увеличения ингибирующей концентрации в профилактической схеме внесения соединений был справедлив для всех соединений эксперимента. Заключение. Представленные синтетические соединения активны в отношении варианта вируса гриппа А, резистентного к римантадину и амантадину. Полученные соединения могут быть использованы в качестве модельных структур для создания нового препарата прямого действия против современных штаммов вируса гриппа А

Virus susceptibility and clinical effectiveness of anti-influenza drugs during the 2010–2011 influenza season in Russia

Background: Antiviral drugs are critical adjuncts to influenza vaccination. This study determined the in vitro susceptibilities of influenza A and B viruses isolated in the 2010–2011 season in Russia to the neuraminidase inhibitor oseltamivir and the hemagglutinin fusion inhibitor umifenovir and clinical efficacy of this antiviral drugs in this season. Methods: The antiviral potency of these drugs against A(H1N1)pdm09 virus in mice was assessed. Importantly, the clinical effectiveness of oseltamivir and umifenovir was evaluated in a retrospective study conducted in 26 regions of Russia. Results: All tested viruses (n = 36) were susceptible to oseltamivir and umifenovir in vitro. Oseltamivir (10 mg/kg/day) and umifenovir (60 mg/kg/day) significantly increased the survival of mice challenged with A/California/04/2009 (H1N1)pdm09 virus (p < 0.05). Influenza infection was laboratory-confirmed in 442 patients among 1462 patients hospitalized with acute respiratory infections. The treatment of influenza-infected patients within 48 h of symptom onset with oseltamivir and umifenovir was associated with a significant decrease in the duration of illness (2–3 days) and symptoms (p < 0.001). Pneumonia was observed in none of the patients treated with oseltamivir and in 0.3% of the patients treated with umifenovir, compared to 23.7% of patients who did not receive antiviral therapy (p < 0.001). Conclusions: This study provided experimental and clinical evidence of the efficacy of oseltamivir and umifenovir against influenza viruses, representatives of which have continued to circulate in post-pandemic seasons

Acute, recurrent and repeat respiratory infections in children: the issues of immunoprophylaxis and immunotherapy

A.L. Zaplatnikov1, A.A. Girina2, E.I. Burtseva3, I.V. Lepiseva4, I.D. Maykova5, V.I. Svintsitskaya1, M.V. Leshik1, N.V. Koroid5, N.F. Dubovets5 1Russian Medical Academy of Continuous Professional Education, Moscow Russian Federation 2Khanty-Mansiysk State Medical Academy, Khanty-Mansiysk, Russian Federation 3D.I. Ivanovsky Institute of Virology, N.F. Gamaleya National Research Center of Epidemiology and Microbiology, Moscow, Russian Federation 4Children's Republican Hospital, Petrozavodsk, Russian Federation 5Z.A. Bashlyaeva Children's City Clinical Hospital, Moscow, Russian Federation The article is focused on the issues of immunoprophylaxis and immunotherapy of acute, recurrent and repeat respiratory infections in children. The authors underscore the high efficacy of active specific immunoprophylaxis against influenza virus, pneumococcal and Hib-infections. They emphasize that the use of combined immunoprophylaxis (vaccine + non-specific immunoprophylactic agents) is effective for achieving the maximal preventive effect, especially in children with recurrent and repeat respiratory infections. The article elucidates such issues as the mode of action and the efficacy of therapy and prevention, as well as the tolerability and safety of topical bacterial lysates in pediatric practice. It also reviews the pathogenetic rationale of using topical bacterial lysate IRS 19 in the prevention and treatment of acute, recurrent and repeat respiratory infections in children. The authors highlight the beneficial therapeutic effects of topical bacterial lysate Imudon on the clinical course of infectious and inflammatory oropharyngeal diseases and its preventive action. The authors outline the good tolerability of topical bacterial lysates used in pediatric practice. Taking into consideration that achievement of the most effective prevention of acute respiratory infections (ARI) in children with recurrent and repeat respiratory infections is possible via combination of immunizations, whereas topical bacterial lysates can be applied successfully as non-specific immunoprophylactic agents. Keywords: vaccination, influenza, children, immunity, immunotherapy, immunoprophylaxis, acute respiratory infections, recurrent respiratory infections, repeat respiratory infections, topical bacterial lysates, trained immunity, frequently ill children. For citation: Zaplatnikov A.L., Girina A.A., Burtseva E.I. et al. Acute, recurrent and repeat respiratory infections in children: the issues of immunoprophylaxis and immunotherapy. Russian Journal of Woman and Child Health. 2023;6(1):50–59 (in Russ.). DOI: 10.32364/2618-8430-2023-6-1-50-59. </p

Monitoring of the sensitivity of epidemic influenza virus strains isolated in Russia to etiotropic chemical agents

The paper presents the results of studying the spectrum of influenza A and ? virusee to rimantadine, arbidol, and oseitamivir and describes the methods used for these purposes for epidemiological surveillance. Different sensitivities to rimantadine were found among influenza A viruses During the 2007-2008 season, the vast majority of influenza A(H3N2) virus strains were resistant to rimantadine (77%) while all influenza A(H1N1) virus strains preserved their resistance to this drug. The fact that the epidemic Influenza A(H1N1) virus strains that cany the mutation responsible for resistance to the neuraminidase inhibitor oseitamivir (Tamiflu) circulated in the Russian Federation was first established. At the same time ail the study influenza A(H1N1) virus strains preserved their susceptibility to rimantadine. The sensitivity of the epidemic strains to arbidol has been confirmed

Evolution of pandemic influenza virus A(H1N1)pdm09 in 2009-2016: dynamics of receptor specificity of the first hemagglutinin subunit (HA1)

INTRODUCTION: The new reassortant of the swine flu virus A(H1N1)pdm09, which emerged in 2009, overcame the species barrier and caused the 2009-2010 pandemic. One of the key points required for the influenza virus to overcome the species barrier and adapt it to humans is its specific binding to the receptors on the epithelium of the human respiratory tract. PURPOSE: Studying the dynamics of changes in receptor specificity (RS) of the HA1 subunit of the hemagglutinin of the influenza A(H1N1)pdm09 virus strains isolated during the period 2009-2016 on the territory of the Russian Federation, and an analysis of the possible impact of these changes on the incidence rates of the population of the Russian Federation of pandemic influenza in certain epidemic seasons. MATERIAL AND METHODS: Standard methods of collecting clinical materials, isolation of influenza viruses, their typing and genome sequencing were used. For the study of RS of influenza A virus (H1N1)pdm09, the method of solid phase sialosidenzyme analysis was used. RESULTS: It is shown that the change in the parameter W3/6 , which characterizes the degree of a2-3 receptor specificity (a2-3-RS) of the influenza virus A(H1N1) pdm09 over a2-6-RS, coincides with the change in the incidence rates of the Russian Federation's pandemic flu in separate epidemic seasons. There is a tendency to increase the affinity of the virus A(H1N1)pdm09 to α2-3 analogs of the sialyl-glycan receptors of the human respiratory tract epithelium - α2-3-sialoglycopolymers (α2-3-SGP), and falls to α2-6-SGP, with the virus showing the greatest affinity for sulfated sialoglycopolymers. DISCUSSION: Screening for RS strains of influenza A (H1N1)pdm09 virus isolated on the territory of the Russian Federation in 2009-2016 revealed a decrease in the affinity of viruses for a2-6-sialosides, especially for 6'SL-SGP, which is probably due to the presence of amino acid substitutions in the 222 and 223 positions of RBS HA1 viruses. Previous studies have shown that the presence of such substitutions correlates with an increase in the virulence of the influenza A virus (H1N1)pdm09 [16, 23]. Probably, the pandemic virus has evolved towards the selection of more virulent pneumotropic variants. CONCLUSION: Monitoring of the receptor specificity of a pandemic influenza virus makes it possible to identify strains with altered RS to the epithelium of the human respiratory tract and an increased ability to transfer from person to person. Change in the period 2009-2016 the W3/6 parameter characterizing the degree of α2-3-RS excess of the influenza A(H1N1)pdm09 virus over α2-6-RS, coincides with the change in the incidence rates of the pandemic influenza population of the Russian Federation in certain epidemic seasons

Monitoring of the sensitivity of epidemic influenza virus strains isolated in Russia to etiotropic chemical agents

The paper presents the results of studying the spectrum of influenza A and ? virusee to rimantadine, arbidol, and oseitamivir and describes the methods used for these purposes for epidemiological surveillance. Different sensitivities to rimantadine were found among influenza A viruses During the 2007-2008 season, the vast majority of influenza A(H3N2) virus strains were resistant to rimantadine (77%) while all influenza A(H1N1) virus strains preserved their resistance to this drug. The fact that the epidemic Influenza A(H1N1) virus strains that cany the mutation responsible for resistance to the neuraminidase inhibitor oseitamivir (Tamiflu) circulated in the Russian Federation was first established. At the same time ail the study influenza A(H1N1) virus strains preserved their susceptibility to rimantadine. The sensitivity of the epidemic strains to arbidol has been confirmed

Clinical and laboratory profile of patients with COVID-19 admitted to hospital in Moscow between may and july 2020

Objective. Data of the clinical picture forms of the disease, management and diagnostic capabilities of patients with COVID-19 continue to be studied. Our study presents results from the analysis of clinical and laboratory parameters of patients with COVID-19 in the period May-June 2020, who were treated in an infectious diseases hospital in Moscow. Patients and methods. The analytical cohort included 444, 198 men, 246 women aged 18 to 95 years, who were identified with SARS-CoV-2 RNA. The severity of the disease was determined in accordance with the temporary clinical recommendations (version 6 effective April 28, 2020), NEWS. Results. The study of the clinical picture showed the variability of the spectrum of clinical manifestations of COVID-19. The most common symptoms were fever, weakness, myalgia, dry cough, shortness of breath, diarrhea. The severity of the infection was not associated with the patient's gender, but was significantly correlated with age and the presence of comorbid status, which included chronic lung diseases, obesity, diabetes mellitus, and cardiovascular diseases. Observations of patients with severe and extremely severe course revealed characteristic laboratory markers of severity. The main method of etiological diagnosis was the RT-PCR method for detecting SARS-CoV-2 RNA in the nasopharyngeal secret. To verify COVID-19, we used an additional PCR method, fecal testing for the detection of SARS-CoV-2 RNA. © 2021, Dynasty Publishing House. All rights reserved