The effect of the intra- and extracellular metabolites of microorganisms isolated from various ecotopes on the catalase activity of Staphylococcus aureus 6538P

The cell extracts (i.e., intracellular metabolites) and culture liquids (i.e., extracellular metabolites) of microorganisms isolated from various ecotopes were found to inhibit the catalase activity of Staphylococcus aureus ATCC 6538P, which resulted in a considerable inhibition of the growth of metabolite-treated S. aureus cells by hydrogen peroxide. The inhibitory effect of microbial metabolites on S. aureus catalase can be considered as a mechanism of intercellular interactions responsible for the formation of microbiocenoses.     

Colicinogenic activity of intestinal microflora as a sign of dysbacteriosis of the gastrointestinal tract

Clinical and bacteriological studies have revealed that the production of colicin by Escherichia coli forming a part of intestinal microbiocenosis is related to the clinical manifestations of inflammatory diseases of the gastrointestinal tract. During the exacerbation of chronic inflammatory processes of the digestive system the proportion of colicin producing E. coli increases (more than 45%) in comparison with that of E. coli fecal strains isolated in children and adolescents regarded as healthy (less than 15%). The possibility of using the colicin producing activity of intestinal microflora for the evaluation of the dysbiotic states of gastrointestinal tract is discussed.     

Enzyme-substrate mode of action for bacteria survival in water biotic community

The role of enzyme--substrate interactions for the survival of bacteria in natural biocenoses has been analyzed with the systems "lysozyme-antilysozyme", "histon-antihiston" used as models. The conception of a possible universal mechanism for supporting the circulation of pathogenic and opportunistic microorganisms among eukaryotes, irrespective of their evolutionary status and environment, has been formulated. This mechanism is ensured by the natural resistance of the eukaryotic cells and by persistence factors on the part of the pathogen; as a result, the dynamic system of interactions is formed which facilitates the survival of microorganisms due to their persistence potential. New knowledge thus obtained opens prospects in the study of sanitary and ecological aspects of water biocenoses.     

Characterization of relationships between pro- and eukaryotic cells under the conditions of intracellular symbiosis of Staphylococcus aureus in the mucosa cells of the respiratory and digestive systems organs in terms of ecology and morphology

The ecological and morphological analysis of reorganization processes in the cell and tissue structures of the mucous membranes of the respiratory and digestive systems in rats under the conditions of their prolonged symbiotic interactions with staphylococci (in the body of rats as a whole, as well as on the model of organotypic cultures in diffusion chambers in vivo) was carried out with the use of light and electron microscopy, radioautography and morphometry. The morphological equivalents of phenotypic reactions in the cell elements of the mucous membranes of the respiratory and digestive systems (epitheliocytes, leimyocytes, endotheliocytes, macrophages and fibroblasts) under the conditions of staphylococcus persistence were revealed. Adaptive and reactive shifts in eukaryotic cells were manifested by an increased volume of nuclei and greater proportion of euchromatin and a decreased DNA-synthetic and proliferative activity. Microorganisms located inside the cells underwent ultrastructural reorganization.     

Characteristics of changes in microbiocenosis in patients with chronic nonspecific urethritis

The species composition and the complex of biological characteristics of microflora in the front section of urethra in healthy males and in patients with chronic nonspecific urethritis. The study revealed that in patients with chronic nonspecific nongonococcal urethritis changes in the microbiocenosis of the urethra were observed. These changes were manifested by a decrease in the number of species, the appearance of Grain-negative enterobacterial flora and an increase in the persistence potential of symbiotic bacteria. These disturbances are regarded as the manifestation of urogenital dysbiosis.     

Interaction of bacteria and red blood cells

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.