Comparing of level of circulation of respiratory viruses during epidemic seasons 2015–2020 and COVID-19 pandemic in Saint Petersburg

BACKGROUND: Respiratory viruses circulate everywhere. Problem of pandemic respiratory virus SARS-CoV-2 is especially relevant. The understanding of level of circulation of different viruses can help in developing a strategy of respiratory viruses combat. AIM: To compare circulation of respiratory viruses during different seasons. MATERIALS AND METHODS: PCR-diagnostic. RESULTS: The most common viruses before the pandemic were influenza and respiratory syncytial viruses. COVID-19 pandemic season 2020/2021 had significant difference from previous epidemic seasons. Influenza viruses have largely disappeared, but the circulation of seasonal coronavirus and metapneumovirus has increased. The circulation of rhinovirus remained at the same level. CONCLUSIONS: The emergence of pandemic SARS-CoV-2 virus had a significant impact on some respiratory viruses circulation, such as influenza or respiratory syncytial viruses.

Protective role of silver nanoparticles in influenza infection

BACKGROUND: The present study assesses copper metabolism of the host organism as a target of antiviral strategy, basing on the virocell concept. This concept suggests that the targets for suppressing viral reproduction can be found in the hosts metabolism. AIM: Evaluation of the effect of copper status indicators on influenza infection in mice. MATERIALS AND METHODS: Silver nanoparticles (AgNPs) were used as a specific active agent because they reduce the level of holo-ceruloplasmin, the main extracellular cuproenzyme. The mouse model of influenza virus A infection was used with two doses: 1 LD50 and 10 LD50. The following treatment regimens were used: mice were pretreated four days before infection and then every day during infection development until the end of the experiment (day 14). RESULTS: The mice treated with AgNPs demonstrated significantly lower mortality, the protection index reached 6070% at the end of the experiment, and mean lifespan was prolonged. In addition, the treatment of the animals with AgNPs resulted in normalization of the weight dynamics. Despite the amelioration of the infection, AgNPs treatment did not influence influenza virus replication. CONCLUSIONS: This study provides support for the view that silver nanoparticles could be used as protection against influenza.

Psychosomatic disorders (distress, depression, anxiety, somatization) in young patients who have had COVID-19

AIM: The mission is to assess possible psychosomatic disorders (in particular, stress as a nervous breakdown, an acute temporal phase of a specific disorder, which is manifested primarily by signs of depression and neurosis) in young patients who have had COVID-19, in the course of rehabilitation, to improve medical and psychological support after their discharge from the hospital. MATERIALS AND METHODS: 60 convalescents who have had COVID-19 and had practically been healthy before (men aged 19.87 1.64 years) were examined. The main clinical variants and manifestations of COVID-19 in our study were inapparent infection (II) in 19 cases (31.67%), acute respiratory viral infection (ARVI) in 21 cases (35.0%), pneumonia without respiratory failure (P) in 20 cases (33.33%). These are clinical variants and manifestations of mild-to-moderate of COVID-19 severity. The diagnosis of all clinical variants and manifestations of COVID-19, the patients examination, treatment and discharge from the hospital were carried out in accordance with regulatory documents. The patients were examined 68 month after discharge from the hospital. Psychometric examination of these individuals to separate their clinical manifestations of distress and somatization and manifestations of depression and anxiety was carried out according to the questionnaire The Four-Dimensional Symptom Questionnaire, 4DSQ), developed in 1996 by the Dutch specialists B. Terluin. This questionnaire was translation into Russian and adapted by A.B. Smulevich et al. [2014]. Voluntary informed consent was obtained from each of the patients before their participating the study. RESULTS: Indicators of distress, anxiety, somatization after all the clinical variants and manifestations of COVID-19 have a moderately increased level, which indicates a serious illness that has been suffered, in some cases with an unfavorable outcome. The strongly increased level of depression in our study is probably due to the presence of astheno-neurotic syndrome due to the previous COVID-19 disease. The data on the correlation between the scales of methods indicate the direction of possible psychoprophylactic work with convalescents. CONCLUSIONS: The results of the study showed that young patients without concomitant diseases who have had COVID-19, even with a mild and low-symptom course, may develop psychosomatic consequences such as distress, anxiety, somatization and some others. The reasons, duration, potential risk factors for their development require further study, however, timely developed preventive and therapeutic and diagnostic measures, taking into account the individual characteristics of the patient, can have a positive effect.

Destructive effect of RNаse a on the SARS-CoV-2 virus (in vitro research)

BACKGROUND: For today, the most important and discussed issue in the professional medical community is the problem of prevention and treatment of a new coronaviral infection (COVID-19). The main reason for the non-decreasing increase in morbidity and mortality is the absence of an etiotropic drug. In our study, it is proposed to use a previously available drug for the treatment of tick-borne encephalitis, ribonuclease A, obtained from the pancreas of cattle. AIM: The aim of investigation was to study the antiviral activity of RNаse A against SARS-CoV-2 in in vitro experiments. MATERIALS AND METHODS: The experiment used samples of 50 patients with a confirmed (by PCR) primary diagnosis of a new coronoviral infection COVID-19. The preparation for the study was served by ribonuclease A (neoFroxx GmbH, Germany) at a concentration of 0.5; 1; 5 and 10 mg/ml, incubated at 4 and 37C, the exposure was 20 minutes, 20 hours. A set of reagents OTT-PCR-RV-SARS-CoV-2 (Syntol, Russia) was used as test systems. RESULTS: of the current study is the revealed antiviral activity of ribonuclease A at a minmal concentration of 0.5 mg/ml during incubation from 20 minutes to 20 hours, in the temperature range of 437C. CONCLUSIONS: The data obtained in the in vitro study confirmed the ability of ribonuclease A to destroy viral RNA, which suggests the possible use of the drug both for the treatment of patients and for the treatment of environmental objects.

The role of coinfection with influenza viruses in the pathogenesis of severe infection in patients with COVID-19

BACKGROUND: Despite the continuing global spread of the coronavirus infection COVID-19 caused by the SARS-CoV-2 coronavirus, the mechanisms of the pathogenesis of severe infections remain poorly understood. The role of comorbidity with other seasonal viral infections, including influenza, in the pathogenesis of the severe course of COVID-19 remains unclear. MATERIALS AND METHODS: The present study used sera left over from ongoing laboratory studies of patients with varying degrees of severity of COVID-19. The study was approved by the Local Ethics Committee of the Federal State Budgetary Scientific Institution IEM (protocol 3/20 from 06/05/2020). We studied 28 paired samples obtained upon admission of patients to the hospital and after 57 days of hospital stay. Paired sera of patients with COVID-19 were tested for antibodies to influenza A and B viruses. The presence of IgG antibodies specific to the SARS-CoV-2 spike (S) protein was studied using an enzyme-linked immunosorbent assay (ELISA). The serum concentration of C-reactive protein and the neutrophil-lymphocyte ratio on the day of hospitalization were also assessed. RESULTS: At least a 4-fold increase in serum IgG antibodies to SARS-CoV-2 S protein was found both in patients with PCR-confirmed SARS-CoV-2 infection and without PCR confirmation. It was shown that out of 18 patients with moderate and severe forms of COVID-19 infection, six of them showed at least a 4-fold increase in antibodies to influenza A/H1N1, in one to influenza A/H3N2 and in two cases to the influenza B. Laboratory data in these two groups were characterized by significant increases in serum C-reactive protein and neutrophil-lymphocyte ratio concentrations compared with the moderate COVID-19 group. CONCLUSIONS: Serological diagnostics can additionally detect cases of coronavirus infection when the virus was not detected by PCR. In moderate and severe cases of COVID-19, coinfections with influenza A and B viruses have been identified. The results obtained confirm the need for anti-influenza immunization during the SARS-CoV-2 pandemic. Influenza virus screening can significantly improve patient management because recommended antiviral drugs (neuraminidase inhibitors) are available.

Amphotericin b effect on the sensitivity to influenza infection of WI-38 VA-13 cells with IFITM3 gene knockout

BACKGROUND: The application of CRISPR/Cas9 is one of the most rapidly developing areas in biotechnology. This method was used to obtain clones of а human origin cell line with knockout of one or more genes of the IFITM family, representing host restriction factors for influenza infection. Amphotericin B has previously been shown to promote influenza infection by blocking IFITM3 function. AIM: The aim of this study was to evaluate the effect of amphotericin B on the sensitivity of IFITM knockout cells to influenza A virus infection. MATERIALS AND METHODS: WI-38 VA-13 cells and mutant clones with IFITM3 knockout (F3 clone) or IFITM1, IFITM3 knockout (clone E12) were infected with influenza virus A/PR/8/34 (H1N1) in the presence or absence of amphotericin B. Forty-four hours after infection, the culture medium was taken to determine the infectious activity of the virus by titration in the MDCK cell culture, as well as the hemagglutinating activity of the virus. The infected cells were stained with fluorescently labeled antibodies against the viral NP protein, and the number of NP-positive cells was determined by flow cytometry. RESULTS: The addition of amphotericin B increased the hemagglutinating and infectious activity of the virus in WI-38 VA-13cells, while the difference was insignificant for clones with IFITM gene knockout. A similar dependency was obtained for the percent of infected cells. CONCLUSIONS: Mutant cells with a knockout of one or several genes of the IFITM family were equally susceptible to influenza infection regardless of the addition of amphotericin B, which confirms the crucial importance of a defect in the IFITM3 protein in increasing the permissiveness of cells to influenza A virus.

Rational selection of hemagglutinin variants of H3N2 influenza viruses in preparation of live influenza vaccine strains to optimize growth characteristics

BACKGROUND: Up to date Russian live attenuated influenza vaccines are produced in developing chicken embryos. During passaging in embryos, the virus isolated from the human respiratory tract undergoes adaptation to the receptors in embryos. The population of the virus, at any passage in chicken embryos, is heterogeneous and contains variants of viruses with one or another set of adaptive substitutions. Before preparing the vaccine strain, the population of the epidemic virus is cloned and the genetic sequence of the hemagglutinin and neuraminidase clones is analyzed. The growth characteristics of the vaccine strain and its antigenic properties depend on the correct choice of the variant of the virus. AIM: The aim of the study was to select the variant of the H3N2 subtype virus for the preparation of a vaccine reassortant based on data on the composition of the population and an assessment of its growth properties. MATERIALS AND METHODS: Viruses were cloned in developing chicken embryos, sequencing of the hemagglutinin and neuraminidase genes of the clones was performed. On the basis of the clones selected based on the results of the analysis of the population, strains of a live influenza vaccine were obtained by the reassortment in the chicken embryos. The growth characteristics of the strains, the phenotype in eggs, and the antigenic properties by hemagglutination inhibition test were evaluated. RESULTS: The influenza virus A/Kansas/14/2017 recommended by WHO for the epidemic season 2019-2020 acquired a pair of D190N + N246T substitutions dominating in the population at the 7th passage in eggs. From the population of A/Kansas/14/2017-like strain A/Brisbane/34/2018, from the third passage in the eggs, it was possible to obtain a variant of the virus with substitutions G186V + S219Y in hemagglutinin. The growth characteristics of the strain based on A/Kansas/14/2017 (passage E7) were significantly inferior to the characteristics of the strain based on A/Brisbane/34/2018 (passage E3), in the absence of differences in antigenic properties. CONCLUSIONS: The variant of egg adaptation of hemagglutinin G186V in strains of clade 3c.3a is preferable for the preparation of live influenza vaccine strains; variant N246T is not optimal. When preparing strains, it is necessary to analyze the composition of the virus population by cloning and choose the most optimal option for preparing strains. The persistence of egg-adaptive substitutions in passaged variants of the virus is not always optimal for strains of live influenza vaccine, and therefore it is preferable to use the population as close as possible to the initial variant to start work on the strain.

Infectious complications in patients with chronic lymphocytic leukemia treated with bruton’s tyrosine kinase inhibitors

The aim of this study is to analyze the scientific literature data on the frequency and characteristics of infectious complications during the treatment of patients with lymphoproliferative diseases with a new class of drugs, selective inhibitors of Brutons tyrosine kinase (BTK). This work describes the indications for appointing these drugs as well as the participation of BTK in the development and activation of B cells. We have studied the main characteristics of BTK inhibitors used in clinical practice and associated disorders in the activity of off-target tyrosine kinases. The work describes the main types of known infectious complications developing during the treatment with the drugs of this group, the period of their appearance, and characteristic pathogens.

Optimization of M2e cassette amino acid composition for the development of universal influenza vaccine

The development of a universal influenza vaccine with a wide spectrum and duration of action is one of the serious public health problems. This study is dedicated to optimization of an immunogen covering the M2e epitopes of influenza A viruses circulating in the natural reservoir, as well as the creation of a prototype of a universal influenza vaccine with subsequent quantitative and qualitative assessment of the induced anti-M2e responses in ferrets.

The features of the course of virus-associated acute lung injury in mice with induced immunosuppression

BACKGROUND: Among all groups of patients with virus-associated acute lung injury with influenza infection, the most severe course is observed in patients with immunosuppression. In this case, despite the studied mechanism of the course of combined pathology, the question of therapy in this group of patients remains unclear. AIM: To study the features of the course of acute lung injury in influenza infection with secondary immunosuppression in an experiment for the possibility of searching for experimental therapy for this combined pathology. MATERIALS AND METHODS: The study was performed on 115 outbred female mice. The mouse-adapted pandemic influenza virus A/California/7/09MA (H1N1)pdm09 was used for modeling viral acute lung injury. Experimental immunosuppression was reproduced by administration of methotrexate (1.25 mg/kg intraperitoneally, once every 3 days during 3 weeks before infection). During the experiment, mortality, blood oxygen saturation, the concentration of pro-inflammatory cytokines in the lungs, and the severity of lung injury were measured. RESULTS: The presence of experimental immunosuppression led to an exacerbation of acute lung injury in infected animals in terms of mortality and lung damage. Changes in the dynamics of proinflammatory cytokines (TNF-, IL-6, IL-1) in the lungs were observed during acute lung injury. Retarded recovery of the lungs functional activity was noted. CONCLUSIONS: The experimental immunosuppression contributed to the exacerbation of acute lung injury and to an increase in the duration of the pathology. These changes could be associated with an altered process of elimination of the pathogen. The reproduced model of combined pathology was used for searching a therapy for these complications.