Vol 12, No 6 (2022)

Helicobacter pylori (H. pylori) is widely considered to be one of the oldest bacteria in the human microbiome. During the co-evolutionary relationships between humans and H. pylori bacterium, spanning at least 100 000 years, a high rate of mutation and recombination events led to extremely high genomic polymorphism of the H. pylori species. Despite this, the large diversity of H. pylori genomes is very well structured, allowing to divide it into different populations associated with the geographic location of H. pylori strains. To date, seven modern H. pylori populations have been determined globally: hpAfrica1, hpAfrica2, hpEastAsia, hpEurope, hpAsia2, hpNEAfrica and hspSahul originated from at least six ancestral populations (ancestral European 1, ancestral European 2, ancestral EastAsia, ancestral Africa1, ancestral Africa2, ancestral Sahul). The global phylogenetic analysis showed that H. pylori is organized into two superlineages: one containing hpAfrica2 and the other containing all other populations in a single monophyletic clade. This indicates that, hpAfrica2 is the most ancient of all H. pylori populations, while the others continued evolutionary development along as mankind spread beyond the African continent. Thus, the H. pylori species populational diversification, which occurred in parallel with paired hosts, allowed us to use H. pylori genetic variants as biological markers, reflecting ethnogeographic migration processes in human history. Moreover, the rapid and dynamic evolution of H. pylori informs about ongoing recombination events enabling use H. pylori as a model both for the co-evolution of pathogenic bacteria and humans as well as for within-individual host pathogen microevolution. This review summarized developments from numerous studies on coevolution process and phylogenetic pattern of the global H. pylori population. The relationships between currently known bacterial populations and subpopulations, related geographical distribution, reconstruction of evolutionary pathway for ancestral and recent populations are detailed. New data on the H. pylori strain populational pattern in Russia, as well as strains circulating in the Northern, Central and South America, are presented. Phylogenetic analysis of the H. pylori population pattern permitted to reconstruct both prehistoric and recent human migrations, demographic processes as well as multilayered evolutionary pathways of H. pylori population.

Currently, the disease caused by the new coronavirus (COVID-19) and the possibility of co-infection with SARS-CoV-2 and other pathogens in the current epidemic situation continues to be of particular interest. The review, based on the analysis of literature and own materials, outlines the features of the relationship between SARS-CoV-2 and pathogens of acute respiratory viral infections (ARVI). Particular attention is paid to the combined course of COVID-19 and influenza, a comparative characteristic of the severity of the clinical picture. An assessment of the epidemic situation against the backdrop of the COVID-19 pandemic in foreign countries and the Russian Federation (RF) revealed the presence of the phenomenon of SARS-CoV-2 interference with other viral respiratory agents, based on the facts of a sharp suppression of the circulation of influenza viruses, respiratory syncytial virus (RSV) and other ARVI pathogens during the period of active spread of pandemic coronavirus. The main epidemiological indicators of the course of coronavirus infection were compared and the contribution of various pathogens to the etiology of acute respiratory viral infections during the development of the second wave of COVID-19 in the RF was assessed. It was noted that the decrease in the number of new cases by 11.4 and deaths by 2.1 times due to COVID-19 at 6 and 13 weeks in 2022 occurred with unchanged laboratory detection of the influenza virus (0.8%) and an increase in the frequency detection of pathogens of other SARS. The results of observations showed that against the background of a decrease in the incidence of COVID-19, there was no increase in the proportion of diagnosed cases of infections caused by other pathogens, especially influenza. The results obtained confirm the need to ensure effective epidemiological surveillance and additional application of pathogen identification methods for monitoring various ARVI, which can significantly affect the approach to differential diagnosis, patient management tactics and the decision on appropriate preventive measures.

The aim of our study was to investigate the main characteristics of peripheral blood NKT cell phenotype in patients with disseminated purulent peritonitis (DPP) in dynamics of postoperative period, depending on the disease outcome. Fifty-two patients with acute surgical diseases and injuries of the abdominal organs complicated by DPP, and 68 healthy individuals in control group, were examined. Blood sampling was performed before surgery (preoperative period), as well as on the day 7, 14 and 21 of postoperative period. All patients with DPP were divided into two groups depending on disease outcome in postoperative period: patients with favorable disease outcome (n = 34); and patients with unfavorable outcome (n = 18). Study of the phenotype of blood NKT lymphocytes was performed by flow cytometry using direct immunofluorescence of whole peripheral blood samples with monoclonal antibodies. The low relative and absolute level of NKT cells was observed in DPP patients regardless of outcome disease in preoperative period. At the same time, the absolute level of NKT cells returned to normal only in patients with favorable DPP outcome and only by day 21 after surgery. Patients with favorable DPP outcome by the end of examination period had normalized quantity of mature NKT-lymphocytes and significantly decreased level of cytotoxic cells which was apparently associated with migration of such cell subsets to site of inflammation. A reduced level of non-classical (expressing CD8 marker) mature and cytokine-producing NKT cells was detected only in patients with favorable DPP outcome in preoperative period which returned to normal by the end of postoperative period. At the same time, patients with unfavorable disease outcome had reduced quantity of NKT cells of these subsets by day 21 of postoperative treatment. Patients with favorable outcome had high level of mature and cytotoxic CD11b⁺ NKT cells already in the preoperative period, while patients with unfavorable DPP outcome had increased level of cytotoxic CD11b⁺ NKT cells only by day 21 after surgery. The proportion of NKT cells expressing activation markers (CD28 and CD57) was reduced in patients in preoperative period that returned to normal immediately after surgery with favorable outcome, while it recovered with unfavorable outcome closer to the end of postoperative examination. The defined features of NKT cell phenotype in patients with unfavorable DPP outcome characterize disturbances in subset ratio and mechanisms of functioning of this cell fraction. This determines a need to develop immunotherapeutic methods aimed at stimulating immunoregulatory activity of NKT cells.

In recent years, it has been extremely evident to seek out for new antibacterial agents, because the burgeoning problem of antibiotic resistance and the toxicity of many antimicrobial compounds has forced scientists to turn attention to alternative approaches. Investigating stem cell secretomes, including the non-protein portion, to find new antimicrobials is a promising area in the field. We examined an effect of the non-protein portion within the embryonic stem cell secretome on various bacterial strains, including antibiotic-resistant members. The non-protein fraction of the stem cell secretome was obtained by preparative high-performance liquid chromatography. Bactericidal activity was tested against eight museum bacterial strains and 206 clinical strains by comparing the secretome-related effects on growth of bacterial cultures. The museum strains showed some dose-dependent effects at concentrations of 25–100 µg/ml. Some bactericidal activity was shown at a concentration of 100 µg/ml against the clinical strains of Gram-negative microorganisms of different species, but bacterial sensitivity to the secretome fraction varied, with growth stimulation being detected in some strains. Applying non-protein fraction of the stem cell secretome at higher concentrations of 100–1000 µg/ml showed no dose-dependent effect. The clinical strains of E. coli and P. aeruginosa were shown to have reduced bactericidal activity after 24-hour incubation. Thus, this study has shown that the non-protein fraction of the embryonic stem cell secretome exerts bactericidal effects against some bacterial strains. However, more detailed studies are needed to identify a mechanism of action and to determine the most effective dose as well as frequency of administration.

This article presents current relevant data on the serogroups and antimicrobial susceptibility of Salmonella strains isolated in the southern provinces of the Socialist Republic of Vietnam. There were examined 189 Salmonella strains isolated from: human feces in acute diarrhea (86 strains); and pork samples (103 strains). Serological O-group identification was performed by slide agglutination with O- and H-antisera and multiplex PCR to detect H phase-1 and phase-2. Antimicrobial susceptibility testing was performed by using the disk-diffusion method according to the EUCAST (version 2019) recommendations. Strains isolated from humans predominantly belonged to O4 group (69.8%). The percentage of other serogroups varied from 1.2% (rare group O16) to 11.6% (O9). About a half of strains (44.7%) isolated from pork samples turned out to belong to the О3,10 serogroup (vs 7.0% of strains from humans). Serogroups О7, О4 and О8 were less frequent (22.3%, 14.6% and 13.6%, respectively). Single strains belonged to serogroups О9, О13, and О18. Regardless of the isolation source, about 80% of Salmonella strains were resistant to antibiotics from different antimicrobial groups (besides carbapenems): 67.0% were resistant to tetracycline; about half were resistant to pefloxacin, ampicillin and chloramphenicol (54.0%, 47.1%, 46.6%); and up to 40% were resistant to trimethoprim/sulfamethoxazole and nalidixic acid. The proportion of strains resistant to ceftriaxone and gentamycin was markedly higher in those of human vs pork origin: 12.8% vs 1.0% and 30.2 vs 1.9%, respectively. Moreover, 62.8% and 43.7% strains of human and pork origin, respectively, showed multidrug resistance (to 3 and more antimicrobial groups). In addition, simultaneous resistance to 6 antimicrobial groups was detected much more frequently in Salmonella strains isolated from humans vs pork samples (15.1% vs 1.0%, respectively). Multidrug resistance (MDR) was observed in strains of different serovars, predominantly S. Typhimurium (36.4%). The predominant MDR (30.3%) phenotype (AMP, TE, QN, C, SXT) was revealed in serovars of S. Typhimurium, S. Bredeney, S. Corvallis, S. Give, S. London, S. Rissen, and S. Meleagridis. Thus, Salmonella strains isolated in the southern Vietnamese provinces featured resistance to fluoroquinolones and cephalosporins. Taking into account simultaneous loss of susceptibility to “old” antimicrobials (ampicillin, chloramphenicol, trimethoprim/sulfamethoxazole), it crucially restricts the list of effective medicines to treat complicated salmonellosis cases.

The post-COVID-19 recovery period is characterized by persistence of some symptoms, with immunological alterations being of great importance. Development of preventive measures to normalize mucosal immunity after a coronavirus infection determines the relevance of the current study. The aim was to study dynamics of clinical symptoms and level of secretory immunoglobulin A in individuals after a novel coronavirus infection as well as evaluate effectiveness of using IFNa-2b. Materials and methods. A study was conducted with patients aged 18 to 60 years old (n = 130), surveyed 1 to 9 months after post-infection, as well as in apparently healthy individuals lacking COVID-19 (n = 15). Previous novel coronavirus infection and post-COVID manifestations were verified based on medical documentation, complaints, anamnesis data, physical examination and questionnaires. The concentration of salivatory and nasopharyngeal mucosal sIgA was measured dynamically prior to and after administration of local therapy with IFNa-2b (gel applied intranasally twice a day for 30 days). Results. The acute period of COVID-19 was characterized by fever, anosmia, severe asthenia (fatigue and weakness), muscle and joint pain. Among the post-COVID manifestations at early period (1–3 months), pain in the joints and muscles (75.0%) as well as elevated body temperature (21.2%) were reliably detected, whereas in the long period (6–9 months) there were revealed dominance with the same frequency of shortness of breath, muscle and joint pain (75.8%, respectively). Based on examination data in healthy subjects, there was determined an arbitrary normal range of secretory IgA in saliva — 6.45±1.81 mg/ml and nasal swabs — 13.43±3.24 mg/ml. In the group of patients 1–3 months post-infection, therapy with IFNa-2b one month later resulted in significantly increased level of secretory IgA in saliva (from 1.84±0.28 to 5.78±1.96 mg/ml) and in nasal swabs (from 28.61±3.0 to 39.83±3.85 mg/ml) by more than 3- and 1.5-fold, respectively. In the group of patients without therapy was featured with stably sustained decline in sIgA level up to 9 months after COVID-19. In particular, the level of saliva sIgA ranged from 2.36±0.56 down to 2.16±0.66 mg/ml, and in nasal smears — from 15.66±1.32 to 10.23±1.07 mg/ml that differed insignificantly compared to baseline level. The rate of respiratory diseases prevailed in this group (27.6% of cases), which fully lacked in the group of topically administered IFNa-2b. Conclusion. In the post-COVID period, multiple organ disorders persist and reduced sIgA level is registered. Intranasally applied IFNa-2b made possible to normalize sIgA level and prevent accumulation of respiratory infectious pathologies.

The aim of the study was to study the dynamics of 24-hour Candida spp. biofilm formation by using a modified macrometric method. The proposed macrometric method solves the problem of accelerating and simplifying the quantitative assessment of the biofilm formation process, increases sensitivity due to allowing to avoid mistakes related to applied polystyrene material. The ease of implementing such a technique makes it accessible to any laboratory. Reference strains from the American Type Culture Collection (ATCC) and clinical isolates of Candida spp. isolated from the female reproductive tract with candida dysbiosis were used for the study. Biofilm formation of Candida spp. studied according to the O’Toole G.A. et al. method modified by us. The biological activity of Сandida sp. biofilm formation was monitored for 48 hours with 4-hour intervals, in winter season, the IV phase of the moon. A 48-hour fungal culture corresponding to relevant maximum adhesion on glass surface was used. The study chrono-design implied obtaining 6 diurnal measurements for the function evaluated with a 3–5-repetits of the experimental conditions. Amplitude-phase characteristics of the studied biorhythms were graphically represented using cosinor analysis serving as the basic method to identify and model cyclic processes in biological systems. The study proved that the ability of micromycete cells to adhere is significantly higher in the stationary vs. logarithmic growth phase (p < 0.05). The chronobiological technique used here allowed to reveal the presence of diurnal fungal film-forming activity (p < 0.05) and reveal the general patterns of manifestated properties in representatives of all candida species examined. It has been experimentally established that the sequence and consistency of the biological properties of clinical Сandida sp. isolates over time were not fundamentally dependent on the type of fungus. During the study, rhythmometric markers of the strain-related pathogenicity was established reflecting contribution of rhythm and the amplitude-phase characteristic. It has been proven that the activity of biofilm formation increases along the “reference strains — clinical isolates” axis. For С. albicans the Mann–Whitney test data was 29, for C. tropicalis — 26, and for C. krusei — 30 (p < 0.05). We believe that chronobiological method opens up new perspectives in the studying physiology of Candida spp. because it allows to dynamically predict state of microorganism and take into account features of urgent and long-term adaptation to various environmental factors. Identifying diurnal rhythms in biofilm-forming activity of various Сandida sp. strains opens up an opportunity to control viability of bacterial-fungal associations and predict related resistance to diverse antimicrobial agents.

Background. Cardiovascular disease (CVD) is the most significant cause of death worldwide. More than 17.9 million people died from CVD, of which 85% deceased due to heart disease. On the other hand, atherosclerosis is one of the most dominant CVD in most developing countries and developed countries. Lp-PLA2 is an enzyme produced by inflammatory cells and a pro-atherogenic protein in atherosclerosis. In the process, monocytes will produce Lp-PLA2 so that it may hydrolyse oxidized low density lipoprotein (oxLDL) into lysophosphatidylcholine (lysoPC) and oxidized fatty acids (oxFA), atherogenic proteins involved in atherogenesis. A chronic inflammatory process that occurs in atherosclerosis requires early detection to avoid CVD severity. The research aims to determine the correlation between Lp-PLA2 concentration and monocyte count as well as percentage in cohorts linked to risk of atherosclerosis. Materials and methods. This study was a descriptive correlational analysis of the population with conditions at risk of atherosclerosis. The total number of respondents sampled in this research was 86. We used the ELISA method to measure Lp-PLA2 concentration and the Hematology Analyzer method to measure monocyte count and percentage. Results. The relationship between monocyte and Lp-PLA2 level accounts for a probability value of 0.028. The correlation coefficient of 0.789 is categorized as very strong. Conclusion. Increase in the concentration of Lp-PLA2 correlates with monocyte count and percentage in a population with conditions at risk of atherosclerosis.

Aim of the study was to assess the current state of implementating key aspects of infection prevention and control (IPC) in Armenian hospitals, defined by the main WHO components, using the survey tool IPCAF (Infection Prevention and Control Assessment Framework). Materials and methods. 113 hospitals were involved in the study. All participants filled out the IPCAF questionnaire, consisting of 8 sections (each rated up to 100 points) devoted to various IPC aspects. Depending on the total final score, IPC programs were divided into the following categories: advanced (601–800 points), intermediate (401–600 points), basic (201–400 points) and inadequate (0–200 points). The study conducted a descriptive analysis of the overall IPCAF score as well as score evaluation of the relevant core components and some selected questions of particular interest. Results. The 2021 total average score for all IPCAF components for all hospitals in Armenia is 578.0±7.9 points, which is currently regarded as an “intermediate” level. At the same time, 47 (41.6%) hospitals were assigned to the advanced category, 63 (55.7%) — to the average category and 3 (2.7%) — to the basic category. Analysis of the main IPC components (CC, Core component) revealed that the maximum average scores were obtained for the components CC2 (IPC Guidelines) — 80.8 points, CC8 (Creating a safe environment in medical premises, as well as materials and equipment for IPC) — 75.5 points and CC7 (Workload, staffing and number of beds) — 75.2 points. The lowest average scores were obtained for the key components: CC4 (Surveillance for healthcare-associated infections) with 54.7 points and CC3 (IPC education and training) with 59.5 points. Conclusion. Legislative and practical changes implemented in the real world during the novel coronavirus infection (COVID-19) pandemic have significantly contributed to improved scores for many key components of IPC programs. The study found that the IPCAF is a useful tool for assessing IPC standards and identifying gaps, regardless of a country economic development level. In our opinion, the re-use of IPCAF in all medical institutions should be encouraged, which is important for monitoring changes and trends in IPC, as well as proposing individual strategies in the development and improvement of IPC.

During more than 50 years, a heterogeneous population of Vibrio cholerae non-O1/non-O139 (NAGs) exists in Rostov region of Russia, whose representatives periodically cause acute human intestinal infections; the last case was registered in 2018. In 2022, a sick child was again revealed in Rostov, from whom 2 NAG subcultures were isolated. Aim of the study: bioinformatics analysis of whole genome sequences (WGSs) of the 2022 clinical NAG isolates, genetic determinants of pathogenicity factors and relevant products. Materials and methods. Isolation, identification of cultures, as well as antibiotic sensitivity were carried out according to the MUK 4.2.3745-22. SNP analysis of WGSs obtained on the MiSeq Illumina platform were analyzed by means of designed software; BioEdit 7.2.5, Vector NTI Advance 11 package, CARD database were used to identify and analyze genes and relevant deduced products. Results. The isolated cultures with identical phenotypic features, PCR-genotypes and results of SNP analysis, were identified as a non-toxigenic NAG. The agent showed sensitivity to chloramphenicol, ceftriaxone, streptomycin, gentamicin, nalidixic acid, ciprofloxacin, ampicillin, amikacin and intermediate resistance to tetracycline, doxycycline, furazolidon and co-trimoxazole. WGSs lacked CTX and preCTX prophages, pathogenicity island VPI, thermostable and cholix toxin genes, pandemic islands VSP-I and VSP-II. The determinants of the type 6 secretion system (T6SS) were not presented completely, which evidenced in favor of the loss of its functionality. An intact T3SS cluster was revealed, which was adjacent to the nan-nag region of the VPI-2 pathogenicity island in the absence of the proximal and distal parts of the latter. Other determinants of pathogenicity factors were revealed: RTX cluster responsible for synthesis of MARTX cytotoxin, genes for hemolysin HlyA, cytotonic toxin Cef, several serine and metalloproteases. The nucleotide compositions of most determinants differed from the prototypes, but their putative products preserved characteristic active domains. The adhesive activity might be provided by mannose-insensitive MSHA-like pili, since the msh-cluster included all the genes necessary for their production, as well as flagella, as both clusters responsible for their assembling were 99% identical to the prototype. From antibiotic resistance determinants only β-lactamase VarG gene was found. Conclusion. The NAG strain examined here contains a sufficient set of intact virulence-associated genetic determinants, expression of which could contribute to the development of the disease.

Fungi are opportunistic microorganisms that colonize all biotopes of the human body, including intestinal. In case of emerging adverse environmental factors (HIV infection, other immunodeficiencies, antibiotic therapy), these microbial representatives begin active reproduction, which might require prescribing antimycotics. Frequent use of the latter in clinical practice induces the development of drug resistance to antifungal drugs, which may impact on effectiveness of both the treatment of fungal infections and other diseases. The purpose of the study was to assess the pattern and spectrum of drug resistance of Candida genus in the intestinal biotope of patients with respiratory tuberculosis and identify risk factors for developing total fungal drug resistance to antimycotic drugs. Material and methods. There were enrolled 21 patients with respiratory tuberculosis. Pattern of the fungal species diversity for the Candida genus isolated from faeces was evaluated, and the spectrum of relevant drug resistance to antimycotic drugs was determined. Patients (n = 21) were divided into 2 groups: with (n = 10) and without (n = 11) total resistance to antimycotics, after which the main risk factors for its development were identified. Results. Members of the Candida genus were isolated from all patients examined, wherein pure cell cultures were characterized by high level of antimycotics resistance. Resistance to three drugs was noted in 1 culture (4.8%), to four — in 10 cultures (47.6%), also found in 10 cultures to the entire drug panel (47.6%). During statistical processing, the data were obtained on affecting formation of total resistance to antimycotics of concomitant pathology of the gastrointestinal tract, the presence of a clinically significant dyspeptic syndrome, a history of antimycotic therapy, HIV infection with severe immunodeficiency, and some decrease in the peripheral blood CD4⁺ lymphocyte count. Conclusion. Fungi of the Candida genus isolated from tuberculosis patients were characterized by high level of resistance to antimycotics. Total resistance was observed in 47.6% of patients. In addition, the major fungi colonizing the intestines of tuberculosis patients were found to be Candida albicans species. The risk factors for the development of total antifungal resistance included: chronic enterocolitis, dyspeptic syndrome, peripheral blood CD4⁺ lymphocyte count lower than 350 cells/µl, and history of antimycotic therapy.

The role of viral infection in bronchial asthma (BA) is well-known being reflected particularly in GINA. An effect of pneumotropic intracellular persistent herpesviruses on the course of BA is of particular interest. The most common viruses of this group are cytomegalovirus (CMV), Epstein–Barr virus (EBV), and human herpesvirus 6 (HHV-6). The CMV role has been discussed in our previous publications allowing us to focus here on EBV and HHV-6. We examined 167 children with BA that was diagnosed and clinically assessed in accordance with the current national clinical guidelines. Patients with controlled asthma (70 patients), partially controlled and uncontrolled asthma (97 patients) were stratified into several groups. The detection of EBV and HHV-6 DNA was carried out in throat swabs by PCR; the level of total and virus-specific IgA, IgM, IgG, IgE as well as serum level of IL-4, IL-5, IL-6, IL-7, IL-8, IL-9, IL-10, IL-8 and TNFα was assessed by enzyme linked immunosorbent assay; lymphocyte subpopulations were analyzed by flow cytometry. The dose of topic GCS was taken into account with reference to the fluticosone equivalent; the function of external respiration was studied by spirometry. It was revealed that EBV DNA was found in 14.2% of cases, whereas HHV-6 — in 19.0% of cases, but 14.4% and 52.4% of patients, respectively, shed no pathogen-linked DNA. At the same time, patients with uncontrolled BA are significantly more likely to shed the pathogen DNA, so that EBV is released in 17.1% vs 4.5% of patients with controlled BA, HHV-6 — in 19.5% vs 13.6%. On the contrary, children with controlled BA were significantly more often (63.6% vs 51.2%) negative for viral DNA shedding. Moreover, virus shedding was paralleled with higher levels of IL-5: it was as high as 0.91 pg/ml and 0.29 pg/ml for EBV and HHV-6, respectively; those shedding DNA of both pathogens vs no shedding had IL-5 at level of 0.25 pg/ml vs 0.11 pg/ml. Similar pattern was observed for higher total IgE: 184.5 IU for EBV, 113.1 IU — for HHV-6, and 371.7 IU –shedding both viruses vs 95.2 IU in without DNA pathogen shedding; lower level of FEV1: EBV — 96.6%, HHV-6 — 98.8%, and 106.2% in patients shedding both viruses vs 109.8% in patients not shedding the pathogen DNA. Patients shedding EBV DNA require higher doses of topic GCS to achieve disease control: EBV — 325.0 mg, HHV-6 — 186.4 mg; shedding both viruses — 328.1 mg of topic GCS vs 198.6 mg in patients without pathogen DNA shedding. Thus, activation of both EBV and HHV-6 worsens BA control and aggravates its course, but EBV persistence has a more pronounced effect on the course and control of the disease.

The COVID-19 pandemic is a worldwide problem. The clinical spectrum of SARS-CoV-2 infection varies from asymptomatic or paucity-symptomatic forms to conditions such as pneumonia, acute respiratory distress syndrome and multiple organ failure. Objective was to describe a clinical case of SARS-CoV-2 infection in the patient with sarcoidosis and cardiovascular pathology developing acute respiratory syndrome and lung edema. Material and methods. There were analyzed accompanying medical documentation (outpatient chart, medical history), clinical and morphological histology data (description of macro- and micro-preparations) using hematoxylin and eosin staining. Results. Lung histological examination revealed signs of diffuse alveolar damage such as hyaline membranes lining and following the contours of the alveolar walls. Areas of necrosis and desquamation of the alveolar epithelium in the form of scattered cells or layers, areas of hemorrhages and hemosiderophages are detected in the alveolar walls. In the lumen of the alveoli, a sloughed epithelium with a hemorrhagic component, few multinucleated cells, macrophages, protein masses, and accumulated edematous fluid were determined. Pulmonary vessels are moderately full-blooded, surrounded by perivascular infiltrates. Signs of lung sarcoidosis were revealed. Histological examination found epithelioid cell granulomas consisting of mononuclear phagocytes and lymphocytes, without signs of necrosis. Granulomas with a proliferative component and hemorrhage sites were determined. Giant cells with cytoplasmic inclusions were detected — asteroid corpuscles and Schauman corpuscles. Non-caseous granulomas consisting of clusters of epithelioid histiocytes and giant Langhans cells surrounded by lymphocytes were detected in the lymph nodes of the lung roots. Hamazaki–Wesenberg corpuscles inside giant cells were found in the zones of peripheral sinuses of lymph nodes. In the lumen of the bronchi, there was found fully exfoliated epithelium, mucus. Granulomas are mainly observed subendothelially on the mucous membrane, without caseous necrosis. Histological examination of the cardiovascular system revealed fragmentation of some cardiomyocytes, cardiomyocyte focal hypertrophy along with moderate interstitial edema, erythrocyte sludge. Zones of small focal sclerosis were determined. The vessels of the microcirculatory bed are anemic, with hypertrophy of the walls in small arteries and arterioles. Virological examination of the sectional material in the lungs revealed SARS-CoV-2 RNA. Conclusion. Based on the data of medical documentation and the results of a post-mortem examination, it follows that the cause of death of the patient R.A., 50 years old, was a new coronavirus infection COVID-19 that resulted in bilateral total viral pneumonia. Сo-morbidity with competing diseases such as lung sarcoidosis and cardiovascular diseases aggravated the disease course, led to the development of early ARDS and affected the lethal outcome.