Biomedical subjects
Publications and source records attributed to B Ia Usviatsov.
The results of microbiological spatial monitoring in Orenburg were evaluated. A biological variety of Staphylococcus on the nasal mucosa of schoolchildren were detected. The highest proportion of carriage of the pathogen Staphylococcus was found in different districts of Orenburg, which had the highest air pollution.
The normal microflora of the nasal mucosa in man is differentiated into main, complementary and casual microflora, taking into account its isolation rate and characteristics of microbial contamination. The main microflora of adults, in contrast to children, is represented, in addition to coagulaso-negative (CN) staphylococci, by bacteria of the genus Corynebacterium. In staphylococcal carrier state a decrease in the isolation rate and the amount of bacteria belonging to the main and complementary microflora (CN staphylococci, Micrococcus, Streptococcus, Bacillus) was observed. Moreover, in carriers the weakening of the degree of association between CN staphylococci, Micrococcus, Corynebacterium, Streptococcus in symbiotic pairs was noted. In the absence of S. aureus carrier state the main and complementary microflora was characterized by the combination of the factors of antagonism and persistence, while in carrier state the complex of colonization factors was defective in the main microflora and well pronounced in coagulase-positive staphylococcal strains and enterobacteria.
The description of a new method for the determination of interaction between bacterial strains isolated from the mucous membrane of tonsils of healthy children and patients with chronic tonsillitis. In the analysis of mutual influence of symbionts on the hemolytic, lecitovitellase, lysozyme and antilysozyme activity of microbes isolated from healthy children no changes in the expression of these pathogenicity and persistence factors have been detected in the overwhelming majority of cases (70.8-89.9%). In the microflora of sick children interactions were synergic with respect to pathogenicity factors in 35.2-46.7% of cases and antagonistic in 18.7-31.3% of cases.
25 biocenoses of the microflora of the mucous membranes of the nose and the middle ear in patients having acute and chronic purulent otitis media (epi- and mesotympanitis) were studied. The dynamic study was carried out at the peak of the manifestations of clinical symptoms and on convalescence or improvement of the state of patients. In the process of convalescence the normalization of the composition of the microflora of the nose and the middle ear was found to occur in patients having acute otitis as compared with those having chronic otitis. In chronic otitis dysbiosis was observed in the microflora of the nose and the middle ear (the preservation of Staphylococcus aureus and enterobacterial strains with increased capacity for persistence). Correlation between the taxonomic composition and the biological properties of the microflora of the nose and the middle ear was established. Changes in the properties of individual strains of the microflora in the bacterial interaction of symbionts were more pronounced in the acute form of otitis than in the chronic one.
The review deals with specific features of interactions in microbial biocenoses. The subdivision of the mechanisms of microbial interactions in associations into direct and indirect ones is proposed. The formation of intercellular contacts and matrix belongs to one group of mechanisms, the second group includes the products of metabolism (changes in the physical and chemical composition of the medium, specific growth regulators) and secreted factors (antibacterial substances, pheromones and signal molecules, vitamins, specific mediators). The applied aspects of the knowledge of microbial interactions in the human body are presented.
The persistence properties of 70 S. enteriditis cultures and 12 S. typhimurium cultures isolated from the feces of children of the earliest age groups with the gastrointestinal form of Salmonellosis infection were studied. The study revealed that the low level of persistence properties occurred in most cases of mild forms of the disease. Salmonellae with a high level of anticomplement and antilysozyme activity were more often isolated in cases of moderate and severe forms of salmonellosis. The presence of correlation between the expression of the factors under study and the severity of the symptoms of intoxication in combination with the duration of the diarrhea syndrome in moderate and severe forms of Salmonella infection in children of the earliest age groups was established. The suggestion was made that the evaluation of the persistence properties of bacteria may be used for the prognosis of the course of the infectious process.
The effect of the duodenal contents and its components on the antilysozyme activity (ALA) of enterobacteria was studied. Under the action of native bile and the preparation of dried bile the stimulation of the expression of ALA factor in 86.6-93.3% of enterobacteria was observed. Pancreatin increased the level of the secretion of ALA factor by 50% in comparison with the control. The preparation of egg lysozyme produced no changes in the frequency and level of the expression of ALA factor. The study revealed the dose-dependant character of the action of duodenal contents: in the native form, as well as at concentrations of 50% and 25%, duodenal contents stimulated the expression of the ALA factor of enterobacteria; at concentrations of 12.5% and lower, its effect could be stimulating, inhibitory or neutral.
The interaction of staphylococci, streptococci, meningococci, enterobacteria, leptospires and other microorganisms with red blood cells is considered. Three forms of the interaction of bacteria and red blood cells are discussed: adhesion, the influence of secretory factors on red blood cells, the action of pathogenic bacteria on hemoglobin. The applied aspects of the interaction of bacteria and red blood cells in the human body are presented in accordance with the results of clinical and laboratory studies.
The concentration of hemoglobin in blood of patients with pyoinflammatory diseases was shown to depend on the ability of bacteria to interact with erythrocytes. Bacteria with high hemolytic activity (> or = 70% hemolysis) and anti-hemoglobin activity (>3 g/1) were isolated from pyoinflammatory foci of patients suffering from anaemia. Structural changes were investigated in vitro and in vivo erythrocytes in terms of their interaction with microorganisms by electron microscopy. For the first time, the phenomenon of coccal location within erythrocytes was established. Staphylococci with a high level of hemolytic and anti-hemoglobin activity appear to survive and multiply within erythrocytes that results in destroying hemoglobin. Staphylococci with a low level of mentioned activities are subjected to destructive changes within erythrocytes and subsequent killing.
The patterns of persistence and virulence factors expression in the representatives of human microbial biocenosis depends on a complex of the environmental conditions: influence of microbes-symbionts, biotope peculiarities, properties of microorganisms located within eukaryotes. Interactions of symbionts in pairs "indigen-indigen" isolated from mucous membrane of tonsils in healthy persons, did not lead to changes in expression of pathogenic properties. Interinfluence in pairs "pathogen-indigen" and "indigen-indigen", isolated from patients with chronic tonsilitis were accompanied by an increase of anti-lysozyme, hemolytic and lecithovitellase activities. Migration of strains of non-enzymatized gram-negative bacteria (NEYNB) from nasal into tympanic cavity in experimental acute purulent otitis is connected with an earlier increase of their number in the nasal cavity and the expression of anti-lysozyme activity. In acute and chronic pyoderma, expression of ALA is more marked in bacteria from a perifocal damage in contrast to focal damage of normal skin. In conditions of interaction between erythrocytes and staphylococcal clones with different levels of expression of pathogenic factors, differences were observed in dynamics of hemolytic and anti-hemoglobin activities.
Explore the source record for details and available documents.
The complex study of factors of persistence, virulence and antagonism in 473 coagulase-positive (CP) staphylococci and 489 coagulase-negative (CN) staphylococci inhabiting the nasal mucosa of resident and transitory carriers, and not carriers of CP staphylococci, was made. In the selection of virulent strains of CP staphylococci the factor of anti-interferon activity seemed to be of greater importance than the factor of antilysozyme activity, but the latter was preferable in the selection of virulent strains of CN staphylococci. Biovars of CP staphylococci with a set of factors of persistence, virulence and antagonism were isolated from resident carriers 1.6-3.1 times more frequently than from transitory ones. The selection of virulent biovars could be made among strains of CN staphylococci with pronounced persistent properties, isolated from subjects carrying no CP staphylococci.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
The informative character of staphylococcal persistence factors (antilysozyme and "anti-interferon" signs) as the indices of resident staphylococcal carrier state in the microecological monitoring of the aerial environment was determined. In areas, ecologically unfavorable with respect to the occurrence of diseases of respiratory organs and to the level of air pollution, staphylococcal strains with persistence factors were isolated from children 3 times as often as in areas with low levels of morbidity in respiratory diseases and environmental pollution. The background level resident staphylococcal carrier state was determined (8.1%), permitting the evaluation of the ecological loading and the mapping of the monitored territories.
The suppressive action of a magnet-laser ray and electrolyzed sodium hypochlorite solution on the persistence factors (antilysozyme, "anti-interferon") of Staphylococcus aureus and Neisseria gonorrhoeae is shown. The optimum conditions (time, dose, concentration) for the regulation of the persistence properties of the pathogens has been determined. The use of physicochemical factors in the proposed parameters has been shown to be effective for the therapy of purulent inflammatory diseases and the sanitation of S.aureus carriers.
The microbial biocenosis of the nasal mucosa under normal conditions and in cases of Staphylococcus aureus carriership was studied, taking into account the biological properties of symbionts in 159 persons. In S. aureus carriers the dysbiotic state of the intranasal microflora was established: the decrease of the index of total microbial contamination, the index of contamination with obligate coccal microflora and the index of specific diversity. The factors of the persistence and antagonism of dysbiotic microflora contribute to the mechanism of the development of dysbiosis. In the biocenosis of the carriers obligate microflora strains (Corynebacterium, Micrococcus and coagulase-negative staphylococci) with more pronounced interspecific antagonism or bacteriocinogeny were dominant.