BackgroundEbola virus disease (EVD) is one of the most dangerous and lethal diseases affecting humans. There are several licensed vaccines against EVD, but it remains one of the priority diseases for research and development of effective vaccines.MethodsA double-blind randomized placebo-controlled trial was performed to evaluate safety and immunogenicity of rVSV- and rAd5-vectored vaccine GamEvac-Combi in healthy adults of both sexes between 18 and 60 years. Safety and immunogenicity were assessed during the observation period of 12 months. Immunogenicity was assessed with GP-specific ELISA, IFN-γ ELISA, and plaque pseudoneutralization assay.ResultsVaccinated participants showed marked GP-specific IFN-γ response at day 28 and neutralizing response at day 42 (GMT = 32.6, seroconversion rate 96.3%). GP-specific IgG antibody levels in vaccinated participants peaked at day 42 (GMT = 9345) and persisted for a year after vaccination (GMT = 650).ConclusionThe vaccine showed favorable safety profile and induced robust cell-mediated immune response and strong humoral immune response that lasts at least for a year from the start of vaccination.Clinical trial registrationClinicalTrials.gov, identifier NCT03072030; Pan African Clinical Trial Registry, identifier PACTR201702002053400.

Introduction. COVID-19 is characterized by a varied clinical course. The aim of the work was to identify associations of SNPs of hemostatic system genes with COVID-19. Materials and methods. DNA was isolated from patients (n=117) and healthy participants (n=104). All infected patients were divided into 3 groups, depending on disease severity assessment, which was appreciated by NEWS2. Another group consisted of participants, who had asymptomatic infection in the past. Determination of SNPs of the genes FGB (-455 G/A), FII (20210 G/A), FV (1691 G/A), FVII (10976 G/A), FXIIIA1 (103 G/T), ITGA2 (807 C/T), ITGB3 (1565 T/C), SERPINE1 (-675 5G/4G) were performed by PCR using the Genetics of Hemostasis kit (DNA-Technology, Russia). Results. In analyzed SNPs, no significant differences were detected between the group of infected patients and healthy participants. But significant association was revealed in gene SERPINE1 (-675 5G/4G), when patient groups, differing in the disease severity, were analyzed relative to the group of participants with asymptomatic infection (p=0.0381; p=0 .0066; p=0.0009). It was found, that as COVID-19 severity scores increased, the proportion of 5G allele of gene SERPINE1 decreased, and the proportion of the 4G allele increased (p=0.005; p=0.009; p=0.0005). Similar processes were observed for genotypes 5G/5G and 4G/4G. Discussion. The gene SERPINE1 (-675 5G/4G) is associated with the severity of COVID-19. Conclusion. For the first time, it was discovered that 5G/5G genotype of gene SERPINE1 (-675 5G/4G) can be a marker of a milder course of COVID-19, and the 4G/4G genotype as a more severe one.

The main cause of death in patients with cystic fibrosis (CF) is infectious process in the lungs, in particular, chronic lung infections caused by various pathogens, most often a combination of bacteria, fungi, or viruses. Data on mixed bacterial and viral-bacterial infections from domestic and foreign sources are fragmentary and sparse. The dominant associations of bacterial and viral pathogens in patients with cystic fibrosis have not been studied properly, and data on their epidemiological significance are lacking. The aim of this study was to assess the prevalence of bacterial and viral infections in patients with cystic fibrosis and to substantiate the need for the development of virological monitoring. Methods . Biomaterials from the respiratory tract of CF patients (409 children and 160 adults with CF) examined from 2006 to 2022 were used. The study was carried out using bacteriological methods, molecular genetic methods (RT-PCR) and MALDI-TOF mass-spectrometry. Results . Microflora of the respiratory tract was shown to be mixed in 2/3 patients with CF. The microflora of the lungs of children with CF is a dynamic community of microorganisms with high diversity and variability. In adult patients, associations of microorganisms are more common than in children, but the composition of associations is less diverse. We isolated about 40 species of bacteria from adult patients and more than 85 species from children in our sample. NFMO prevailed, including Burkholderia cepacia complex, Pseudomonas aeruginosa, Achromobacter xylosoxidans, Achromobacter ruhlandii, Stenotrophomonas maltophilia, and Staphylococcus aureus, Candida albicans, Aspergillus spp . Real-time PCR showed the presence of rhinovirus RNA in 10% of samples obtained from children and 12.9% from adults with cystic fibrosis. Conclusion . Our results indicate the need for continuous monitoring of the lung microflora in patients with CF, including testing for viruses.

The study aimed to establish the role of the home environment as a source of Pseudomonas aeruginosa infection in patients with cystic fibrosis.

Objective. To provide a rationale for microbiological monitoring of chronic lung infection caused by Achromobacter spp. in patients with cystic fibrosis (CF) to develop an adequate preventive and therapeutic strategy. Materials and methods. This study included 142 Achromobacter strains isolated from 55 children and 35 adults with CF during their follow-up. In this study, classical microbiological (culture) and modern molecular genetic methods (polymerase chain reaction (PCR), multilocus sequence typing (MLST) and whole-genome sequencing (WGS)), and MALDI-TOF-MS were used. Results. Among the examined patients with chronic lung infection caused by bacteria from the genus Achromobacter, monoinfection was detected in 5.8% of patients. In other cases, associations of Achromobacter spp. with other bacterial species were observed. A. ruhlandii (76%) and A. xylosoxidans (7.2%) were the most frequently isolated species. It was shown that the microbiota in CF patients with chronic lung infection caused by Achromobacter spp. is characterized by variability and is related to long-term circulation of both one genotype with different subpopulation phenotypes and circulation of 2 or more genotypes or species of Achromobacter spp., which has clinical and epidemiological significance. Conclusion. Successful prevention and treatment of Achromobacter spp.-associated infections in CF patients require continuous microbiological monitoring of chronic infection, including that of phenotypic and genotypic properties of Achromobacter spp. strains isolated from patients. Key words: chronic lung infection, Achromobacter sp., microbiological monitoring, genotypic and phenotypic heterogeneity, sensitivity to antibiotics

Relevance. The absence of a system of epidemiological surveillance of chronic lung infection (CLI) in patients with cystic fibrosis (CF) led to the spread of Staphylococcus aureus, Pseudomonas aeruginosa, Burkholderia cepacia complex and Achromobacter spp. among patients with CF during hospitalizations, that is proved by numerous cases of infection in patients with CF treated in various Russian clinics.Aims. Determine the directions of epidemiological surveillance (ES) for CLI in patients with CF and preventive measures necessary to counteract the cross-infections among patients with CF and the spread of the dominant pathogens of CLI in the hospital.Materials and methods. A complex of epidemiological, microbiological and molecular genetic methods was used.Results and discussion. Based on the results of studies of the epidemiological and microbiological features of infections caused by the above-mentioned pathogens, the directions of ES and preventive measures for CF were determined. The tasks of the information-analytical unit, including the monitoring of morbidity and microbiological monitoring, are substantiated. It has been established that in the framework of microbiological monitoring, it is necessary to conduct bacteriological examination of biomaterial from the respiratory tract of patients with CF not less than 1 time per quarter, as well as at each outpatient visit and at hospitalization. The necessity of studying the phenotypic properties of pathogens contributing to long-term persistence in the patient's body of the CF, the definition and monitoring of the antibiotic sensitivity of microorganisms isolated from the patient over time, and the study of hypermutability was shown. One of the main tasks of monitoring is molecular genetic analysis of pathogens by PCR for the purpose of intraspecies identification, typing of pathogens and detection of epidemic markers and clones (including international ones), identification of genetic determinants of antibiotic resistance.Conclusion. The introduction of ES for chronic lung infection will improve the quality of etiological diagnosis, will contribute early identification of the sources of infections and prevent the spread of CLI pathogens among patients with CF in hospitals and in non-hospital conditions, as well as optimize the tactics of CLI antimicrobial therapy. The main directions of preventing the spread of CLI pathogens should be the separation of patients with various infections during outpatient examination and isolation during hospitalization.

ПРИМЕНЕНИЕ СОВРЕМЕННЫХ МЕТОДОВ В МИКРОБИОЛОГИЧЕСКОЙ ДИАГНОСТИКЕ ХРОНИЧЕСКОЙ ИНФЕКЦИИ ЛЕГКИХ У БОЛЬНЫХ МУКОВИСЦИДОЗОМЛ. Р. Аветисян 1 , М

Objective. To present the data on the main mechanism of molecular variation in P. aeruginosa causing chronic lung infection in patients with cystic fibrosis. Materials and Methods. A total of 1800 throat swabs and sputum samples from cystic fibrosis patients were included in the study over the 10-year period. P. aeruginosa isolates were primarily identified by the biochemical method using the API 20NE test strips (bioMerieux, France). Antimicrobial susceptibility testing was performed by disc diffusion method. Genotyping was conducted by RAPD-PCR and MLST. Whole genome sequencing of three typical P. aeruginosa isolates was performed on an Ion PGM Torrent platform with Ion Sequencing Kit and 316v1 chips (Life Technologies Thermo Fisher, US) according to the manufacturer’s protocol. The RAST web application was used for initial annotation. Results. There were three main variants of the pathogen variability found: population heterogeneity, pathogen microevolution, and replacement by another genotype of the same species. The variation of the pathogen’s genome is due to the acquisition of mobile genetic elements (plasmids), mutations in the chromosomal genes responsible for antibiotic resistance, bacterial viability and survival during persistence in a host, and changes in the prophage regions of the pathogen. Conclusions. Epidemiological significance of the molecular mechanisms of pathogen variation is primarily due to the ability of strains to form epidemiologically significant clone. This requires control measures aimed to limit emergence and distribution of such clones to be developed.

The article presents the role of herpesviral infections caused by the herpes simplex virus (HSV), the Epstein-Barr virus (EBV), cytomegalovirus (CMV) and human herpesvirus type 6 (HHV-6) in 36 children with recurrent respiratory tract diseases at the age from 1 to 18 years. Blood sera and blood cells were studied using ELISA, Indirect reaction of immunofluorescence and Rapid culture method.It was found that all 36 children (100%) were infected with HSV, EBV, CMV and HHV-6. Most often — in 19 children (52.8%) the signs of active HHV-6 were revealed. In the same number of children surveyed, it was possible to identify active EBVI (16 children — 44.4%) and CMVI (16—44.4%). Active HSVI was diagnosed in 13 children (36.1%). Herpes virus infections were most often detected in the age group of children from 3 to 7 years of age.All children with recurrent respiratory diseases should be examined for herpesvirus infections.

Objective. To determine the detection rates of HHV-6A and HHV-6B compared to other herpes viruses in children of different age groups. Materials and Methods. A total of 128 patients with symptoms of respiratory viral infections (RVI) aged from 1 to 16 years and 101 otherwise healthy children. A comprehensive examination of the patients, including ELISA, indirect immunofluorescence assay, rapid culture method, PCR, and determination of nucleotide sequences of HHV-6 was performed. Children positive for HHV-6 markers (antibodies, early and late antigens) and positive for HHV-6 DNA were selected into one group (n=59), of which 14 children aged from 3 to 10 years were healthy and 45 children (<3 years of age [20 children] and ≥3 years of age [25 children]) had clinical manifestations of RVI. Results. The incidence rates of acute HHV-6 infection and HHV-6 reactivation were similar between healthy children and children with RVI symptoms (21.9% each). The active Epstein-Barr Virus (EBV) infection took a second place among examined children: acute EBV infection and EBV reactivation were determined in 19 (14.8%) and 10 (7.8%) children, respectively. The incidence rates of HHV-6A and HHV6B among children with RVI symptoms were similar (55.5% and 42.2%, respectively) whereas HHV-6B was predominant in healthy children (85.7%). The HHV-6A was more common (70%) in children under 3 years of age, but HHV-6B was more frequent (67%) in children aged 3 years and older. The most often initial manifestations of HHV-6A infection were acute fever and catarrhal syndrome; whereas HHV-6B was found more frequently in otherwise healthy children. A sudden exanthema and febrile seizures were significantly more common symptoms in children with HHV-6A infection, whereas tonsillar enlargement with exudate and swollen lymph nodes were observed more frequently in children with HHV-6B infection. Conclusions. HHV-6A more often causes acute infection in children less than 3 years of age, which is characterized by fever, febrile seizures, rash (roseola), and upper respiratory tract infection with significant catarrhal syndrome. HHV-6B more often causes acute infection in children aged 3 years and older and is rarely presented with specific symptoms of HHV-6 infection, such as sudden exanthema and febrile seizures. HHV-6B is characterized by lymphoid tissue proliferation (tonsillar enlargement and lymphadenopathy) and hepatomegaly in all age groups of children.

Aim. To evaluate a possible role of herpes viruses in the pathogenesis of various infectious diseases of children in the first six months of life, including acute gastroenteritis and identify the markers of herpesvirus infections which occur most frequently. Materials and methods. Samples of biological materials (blood serum and blood cells, breast milk, urine, feces) were studied in 35 children aged 14 days to 5 months who are being treated in MRRCI Vladimirsky with diagnoses of «acute infectious gastroenteritis of unspecified etiology» (n=24), «urinary tract infection» (n=6), «intrauterine infection» (n=5) and of their mothers. To determine the antibodies of IgM, IgG in serum, an enzyme immunoassay was used, to detect common antigens of viruses in blood cells, urine, breast milk - an indirect reaction of immunofluorescence, to detect early antigens of viruses and their reproduction - a rapid cultural method. Results. Infection with herpesviruses was found in 85% of children and 91% of mothers, with the most often identified markers of active forms of infection caused by the herpes simplex virus. In children with a diagnosis of acute infectious gastroenteritis of unspecified etiology, no pathogens of viral and bacterial intestinal infections were detected in a large number of active forms of herpesviral infections in both children and their mothers (33% and 91%, respectively). As well as mothers and their children, there have been cases of mixed infections caused by associations of herpesviruses, most often with HSV. Conclusion. Detection of active forms of herpesviral infections in the absence of positive results in studies on viral and bacterial intestinal infections make it possible to assume that herpesviruses can participate in the etiology of these diseases and cause infectious complications in this pathology, as well as often act as a co-infection. An important epidemiological importance has a large number of identified latent forms of herpesvirus infections, because when exposed to adverse factors they can go into active forms.

Aim. To study the dependence of detection of markers of opportunistic infections from afherence to antiretroviral therapy in children born to HIV-infected mothers on the example of herpesvirus infectionsand pneumocystis. Materials and methods. Samples of biological materials (blood serum and blood cells) of 66 children with HIV infection aged 1 month to 15 years old were treated in Children’s Boxed Department of Children’s Hospital No. 2 with diagnoses «incomplete HIV test» (children from the age of one month to one and a half years) and «HIV infection». To determine IgM and IgG to herpesviruses and pneumocyst, the method of enzyme immunoassay was used; indirect immunofluorescence reaction for the detection of herpesviruses and their antigens in the blood, early antigens and virus reproduction were determined using a rapid culture method. Results. 56.0% of the surveyed children received complete antiretroviral therapy, in 16,7% of cases they were not complete, and 27,3% of children did not fully adhere to ARVT. Despite the fact that 100% of children with an incomplete diagnosis of HIV infection were covered by ARVT due to the use of chemotherapy drugs by their mothers during pregnancy, they still had markers of both active and latent forms of herpesvirus infections and pneumocystis. In children with confirmed HIV infection living both in social institutions and in families, the markers of opportunistic infections were more often diagnosed in patients receiving ARVT in full and not in full volume than in children who did not have it. Conclusion. Identification of markers of active forms of herpesvirus infections and pneumocystis in HIV-positive children not receiving ARV is the basis for its immediate appointment.

The article is devoted to study the etiological role of herpes viruses in infectious and somatic pathology of children (n = 770) using the complex of methods of laboratory diagnostics. Determined the leading etiological role of HSV in children with neuroinfections (12,7%) during primary infection and in children with intrauterine infection (29,0%) during its reactivation. It is shown that in 50,9% of cases, the diagnosis of «infectious mononucleosis» confirmed by the detection of markers of acute EBV-infection, and 20,0%, it was replaced by mononucleotides syndrome was discovered markers of acute CMV-infection, and 18,1% — markers of acute HHV-6-infection. The role of HHV-6 as the primary etiologic agent of the disease is established at 36,3% of children admitted with convulsive syndrome on the background of febrile, at 29,1% — a sudden exanthema and 25,5% — with fever of unknown origin.

Aim. Study the role of herpes viruses and pneumocystis in infectious complications in children from HIV-infected mothers. Materials and methods. Sera and blood cells from 59 children from HIV-infected mothers were studied for the presence of various markers of herpes virus infections and pneumocystosis by a complex of methods of modem laboratory diagnostics. Results. Frequency of detection of markers of herpes virus infection was from 10% for chicken pox in children with non-final HIV test to 93% for herpes simplex virus in HIV-infected children from closed organized groups. Signs of active infection in children with laboratory confirmed HIV infection were diagnosed 2.5 times more frequently for HSV infection and chicken pox and 1.8 times more frequently for HHV-6 and pneumocystis than in children with non-final HIV test. Markers of various disease stages with opportunistic infections (01) were detected in children with confirmed HIV-infection: primary acute and latent forms of the infection, reactivation, reconvalescence, whereas in children with non-final HIV test maternal antibodies against herpes virus and pneumocystis predominated. Markers of active infections excluding HSV and HHV-6 were more frequently detected in children from families than in children from closed organized groups. Conclusion. The feature detected - a lower percentage of detection of markers of active forms of 01 in HI V-infected children from social institutions - is determined by the fact that observation of these children is carried out by medical personnel that have the knowledge and experience of prophylaxis of infectious complications in HIV-infected children, whereas quality anti-epidemic regimen is frequently not maintained regarding home children with HIV infection. Another factor facilitating spread of opportunistic infections is the asocial lifestyle of most of the examined families. These data dictate the necessity of enhancement of anti-epidemic regimen and prophylaxis of opportunistic infections in family loci. Not only HIV-infected children, but also all the family members should be examined for markers of herpes virus infection and pneumocystosis in order to detect sources of the infection and timely execution of the prophylaxis measures.

Relevance. The absence of a system of epidemiological surveillance of chronic lung infection (CLI) in patients with cystic fibrosis (CF) led to the spread of Staphylococcus aureus, Pseudomonas aeruginosa, Burkholderia cepacia complex and Achromobacter spp. among patients with CF during hospitalizations, that is proved by numerous cases of infection in patients with CF treated in various Russian clinics. Aims. Determine the directions of epidemiological surveillance (ES) for CLI in patients with CF and preventive measures necessary to counteract the cross-infections among patients with CF and the spread of the dominant pathogens of CLI in the hospital. Materials and methods. A complex of epidemiological, microbiological and molecular genetic methods was used. Results and discussion . Based on the results of studies of the epidemiological and microbiological features of infections caused by the above-mentioned pathogens, the directions of ES and preventive measures for CF were determined. The tasks of the information-analytical unit, including the monitoring of morbidity and microbiological monitoring, are substantiated. It has been established that in the framework of microbiological monitoring, it is necessary to conduct bacteriological examination of biomaterial from the respiratory tract of patients with CF not less than 1 time per quarter, as well as at each outpatient visit and at hospitalization. The necessity of studying the phenotypic properties of pathogens contributing to long-term persistence in the patient's body of the CF, the definition and monitoring of the antibiotic sensitivity of microorganisms isolated from the patient over time, and the study of hypermutability was shown. One of the main tasks of monitoring is molecular genetic analysis of pathogens by PCR for the purpose of intraspecies identification, typing of pathogens and detection of epidemic markers and clones (including international ones), identification of genetic determinants of antibiotic resistance. Conclusion. The introduction of ES for chronic lung infection will improve the quality of etiological diagnosis, will contribute early identification of the sources of infections and prevent the spread of CLI pathogens among patients with CF in hospitals and in non-hospital conditions, as well as optimize the tactics of CLI antimicrobial therapy. The main directions of preventing the spread of CLI pathogens should be the separation of patients with various infections during outpatient examination and isolation during hospitalization.