Development of a reagent kit for the qualitative detection of SARS-CoV-2 virus RNA in naso- and oropharyngeal swabs by real-time RT-PCR.

The coronavirus infection continues to spread around the world. In this regard, the purpose of this work was: to develop a set of reagents for the qualitative detection of SARS-CoV-2 virus RNA. The set was developed by CJSC «Ecolab¼, 20 positive samples were used to develop the kit. The research method consisted of several stages: isolation of SARS-CoV-2 RNA, RNA reverse transcription reaction and PCR amplification of cDNA with simultaneous detection of the result in real time. The main characteristics of the kit: analytical sensitivity - 100%, specificity - 100%, accuracy - 100%. Thus, our method for diagnosing a new coronavirus infection based on real-time RT-PCR makes it possible to qualitatively and quickly detect betacoronavirus RNA in clinical material from patients and healthy individuals with suspected coronavirus infection and other symptoms of SARS.

Features of the humoral response to immunization "Gam-COVID-Vac" and in patients with COVID-19.

The paper present the results of a survey of people who have undergone immunization with a combined vector vaccine for the prevention of coronavirus infection COVID-19 «Sputnik V - Gam-COVID-Vac¼, as well as COVID-19 recovalents. Using a quantitative enzyme-linked immunosorbent assay, the levels of specific IgG were determined in persons who had had different degrees of severity before vaccination, in persons who were immuno-negative before immunization, as well as in convalescents who had undergone coronavirus infection of varying severity. The immunological targeting of antibodies against various SARS-CoV-2 proteins is considered.

About quantitative determination of the D-dimer in the blood by immunochromatographic method.

The paper presents the results of the development of a technology for the quantitative determination of D-dimer in blood with an immunochromatographic (LFIA) kit of reagents «LFIA-D-dimer¼ and instrument accounting of the results. Registration and processing of the digitized indicator of the intensity of staining of the LFIA-test strip using the LFIA-analyzer software allows quantifying the D-dimer content in the sample (in ng DDU/ml). The effectiveness of the proposed approach was evaluated on 258 clinical samples examined in the LFIA with visual and instrument accounting of the results, in comparison with the indicators of D-dimer determination in ELISA. The high reproducibility of the digitized LFIA results was shown - the coefficient of variation (CV) for samples in the range of 100-300 ng DDU/ml (near-threshold in relation to pathological values) was 2.5-5.1%; a tendency to increase CV with a further increase in the concentration of D-dimer was traced. A high correlation of the digitized LFIA result with the research data in the ELISA has been established, which makes it possible to recommend the technology for widespread use in urgent medicine.

Assessment of the state of intestinal microbiocenosis based on bacterial endotoxin and plasmalogen in elderly persons with type 2 diabetes mellitus pathology.

The concentration of bacterial plasmalogen 18a and endotoxin in the blood of elderly people 45-90 years old with the pathology of type 2 diabetes mellitus (DM 2) - the main group and without diabetes mellitus - the comparison group was investigated. The concentration of both plasmalogen 18a and endotoxin in the blood of individuals with DM 2 pathology is statistically significantly higher than in the blood of individuals without DM 2 pathology. To assess the state of microbiocenosis and predict type 2 diabetes mellitus, decisive rules have been determined in the form of threshold values of plasma concentrations 18a and endotoxin in the blood of elderly people with a suspected or established diagnosis of type 2 diabetes. Using ROC analysis, it was found that values above 20.66 µg / ml for plasmalogen 18a, and 0.48 nmol / ml for endotoxin, determine the presence of type 2 diabetes mellitus pathology in the 45-90 age group.

[Comparative evaluation of the immunochromatographic test for detection of hemoglobin.] / Сравнительная апробация Ð¸Ð¼Ð¼ÑƒÐ½Ð¾Ñ Ñ€Ð¾Ð¼Ð°Ñ‚Ð¾Ð³Ñ€Ð°Ñ„Ð¸Ñ‡ÐµÑÐºÐ¾Ð¹ тест-системы для выявления гемоглобина в кале.

The evaluating results of the diagnostic characteristics of an immunochromatographic test for the detection of fecal occult blood (hemoglobin) were presents in the article. The test was approved samples without hemoglobin and model samples containing of standardized preparation of hemoglobin in various concentrations in comparison with two immunochromatographic test systems. The developed test system identified hemoglobin in concentrations higher 50 ng/ml in 99,2% cases, the specificity of the analysis was 98,1%. The obtained levels of sensitivity and specificity were higher the similar parameters for the compared test systems. The immunochromatographic FOB-test can be used for rapid analysis in the primary screening of colorectal cancer.

[Development of a set of reagents for detection of class G immunoglobulins to human herpes virus type 7 by the method of immune blotting in the format «Western blot¼.]

A new original domestic set of reagents has been developed for the determination of class G immunoglobulins to individual human herpes virus antigens of type 7 by the method of immune blotting in the "Western-blot" format. Preliminary clinical trials were conducted using 134 serums of healthy children aged 1-16 years who underwent diagnostic testing. Stud y of diagnostic efficiency ofthe new kit showed high sensitivity, comparable to the sensitivity of the reaction indirect immunofluorescence and high specificity, which is manifested in the absence of false positive results when testing samples containing immunoglobulin G to herpes virus 6 type.

[Current trends in the development of resistance to clinically significant antibiotics in Salmonella (review of literature).]

Salmonella is one of the leading bacterial pathogens of acute diarrhea as well as foodborne outbreaks. Salmonellosis can occur as gastroenteritis with the development of complications and generalization of infection, also the extra intestinal diseases that require antibiotic therapy are often registered. Currently, the effectiveness of many antibiotics is reduced due to the development of resistance in Salmonella. National Salmonella surveillance systems monitor Salmonella resistance to «critically important for medicine¼ antibiotics (extended-spectrum cephalosporins and fluoroquinolones), as well as multidrug resistance. Quinoloneresistant Salmonella is considered as a high-priority resitant pathogen by the World Health Organization. The article describes the current situation on salmonellosis in the world. Foreign and Russian current data about the leading Salmonella serotypes in different regions of the world are presented. The prevalence of clinically significant resistance depending of the Salmonella serotypes in countries with state monitoring systems is shown. The authors described the leading molecular resistance mechanisms (chromosomal and plasmid mediated) and showed their prevalence in different Salmonella serotypes. The article gives the information about Salmonella successful international multidrug resistant clones with specific resistance phenotypes and genotypes. The authors describe the molecular methods for detection of resistance mechanisms, and show the necessity and significance of antimicrobial susceptibility monitoring in the epidemiological Salmonella surveillance.

[A system for the automated chemotaxonomic determination of salmonellae and other pathogenic bacteria]. / Sistema avtomatizirovannogo khemotaksonomicheskogo obnaruzheniia sal'monell i drugikh patogennykh bakterii.

On the basis of the data of the gas-chromatographic analysis of the fatty acids of 208 bacterial strains, representatives of 16 different microbial genera, the algorithm of decision taking, necessary for the program provision of investigations, was worked out. In working out the algorithm the characteristics of 30 fatty acids were used, making it possible to classify bacteria with their genera and in some cases their species. The groups of fatty acids with the number of carbon atoms in their molecules ranging from 10 to 25, their melting temperatures and the dependence of relative characteristics of binding from the number of carbon atoms in the molecule of the acid, its chemical composition and the presence of double bonds were taken into consideration. To indicate salmonellae by their fatty acid profiles, a chromatographic system on the basis of a type Crystal 2000 M gas chromatograph is proposed. In addition, the complex method for the determination of bacteria, combining the determination of salmonellae by changes in the medium resistance (impedance) with the use of an electrochemical analyzer and the subsequent identification of the infective agent by its fatty acid profile in the common system of gas-chromatographic investigation, is proposed.

[Potential use of the monosaccharide composition of bacteria for their identification]. / O vozmozhnosti ispol'zovaniia monosakharidnogo sostava bakterii dlia ikh identifikatsii.

The monosaccharide composition of cell hydrolysates can be used as a criterion for the chemical differentiation of gram-positive bacteria. The monosaccharide composition of six bacterial species belonging to the genus Bacillus has been determined using gas chromatography, mass spectrometry and computers. The qualitative composition was similar, glucose, galactose, ribose and glucosamine being the main components in all of the species. Some Bacillus species differed in their minor components. Although the monosaccharide composition appeared to be homogeneous, bacteria can be identified in terms of their carbohydrate profile using computers. To this end, the monosaccharide composition of bacterial cells is represented as a two-dimensional data file including the qualitative composition of components and the quantity of each component.

[Effect of glycolysis on the metabolism of adenylates in human erythrocytes]. / Vliianie glikoliza na metabolizm adenilatov v éritrotsitakh cheloveka.

The ATP content in human erythrocytes depleted without glucose falls down to half of the initial value within 2-3 hours and reaches practically zero within more than 10 hours. The ADP content increases 2-3-fold during the 1st hour after depletion and then slowly decreases. The AMP content increases 10-fold during several hours, but the rate of this process constantly decreases. The adenylate pool decreases at a constant rate ranging from 0.13 to 0.25 mmol/l cell. h; this is accompanied by accumulation of IMP. Addition of glucose to depleted erythrocytes results in partial recovery of the ATP level within 1-2 hours. The sooner glucose addition after the depletion, the greater the recovery. Simultaneously the ADP and AMP levels drastically decrease to new constant values. The decline of the adenylate pool ceases and the rate of IMP accumulation increases. Normally, the [ATP]/adenylate pool ratio lies within the small interval 0.85-0.94 irrespective of significant individual differences in the absolute values of [ATP]. This ratio is decreased during depletion and restored to the initial value after glucose addition. The mass-action ratio of the adenylate kinase reaction changes greatly during depletion and restoration of erythrocyte ATP.