One of the most important requirements for the personnel of microbiological laboratories working with pathogenic and infectious agents is the observance of precautionary measures and the implementation of a set of preventive measures, collectively interpreted as biological safety (biosafety). To a large extent, biosafety problems are also relevant for all clinical laboratories working with biosubstrates, with the potential threat of containing pathogens of bloodborne infections in them. On December 30, 2020, the President of the Russian Federation signed Federal Law № 492 «On the Biological Safety of the Russian Federation» (№ 492-FZ), which regulates the basic legal norms and regulation of biosafety issues, as well as a list of measures to prevent the risks of the spread of infections due to accidents, bioterrorist acts and sabotage.
View Article and Find Full Text PDFOne of the mechanisms underlying the appearance of chronic infections is transition of pathogens into a non-culturable state, which is largely associated with the use of antibiotics. We studied ultrastructure of dormant bacteria Yersinia pseudotuberculosis obtained from the vegetative form of strain 512 by inhibition with kanamycin. On the model of the causative agent of pseudotuberculosis we showed that transition of prokaryotes to a dormant state occurs through apoptosis of bacteria.
View Article and Find Full Text PDFElectron microscopy study revealed changes in the ultrastructure of bacteria of Yersinia pseudotuberculosis strains characterized by significantly reduced reproductive ability and virulence potential after long-term storage at low temperature of 4-8°C. Most bacterial cells contained dark cytosol with reduced cellular material or empty cytosol, while the cell wall was preserved. The revealed ultrastructural changes in the bacterial cells of the static culture of Y.
View Article and Find Full Text PDFBioactive coatings on implants affect osteogenic differentiation of mesenchymal stem cells (MSC). We studied the morphofunctional state of bone marrow MSC cultured on the surface of calcium phosphate coatings on titanium formed by plasma electrolytic oxidation (PEO). The biocompatible properties of the coatings manifested in the absence of the cytotoxic effect on cells.
View Article and Find Full Text PDFThe interest in the problem of enterоpathogenic yersinioses in the world is associated with the ubiquitous distribution of these infections and the clinical significance of their pathogenic agents, Yersinia enterocolitica and Y. pseudotuberculosis. In spite of the novel diagnostic tools, microbiological cultivation on nutrient media still remains the main method of their verification.
View Article and Find Full Text PDFThe dynamics of pathomorphological changes in response to infection with plasmid variants of Yersinia pseudotuberculosis was studied in experimental animals. Variability of cell injuries in pseudotuberculosis histopathology depended on the plasmid-associated virulence of the infection agent. Infection with highly virulent two-plasmid strain pYV48:pVM82 MDa and Y.
View Article and Find Full Text PDFZh Mikrobiol Epidemiol Immunobiol
November 2016
Literature data regarding genetically-determined pathogenicity factors of Y pseudotuberculo- sis and associated manifestations of this infection caused by various plasmid types of the causative agent are generalized. Principal attention is given to features of cell-tissue alterations mediated by virulence plasmid pYV, as well as effects of pathogenicity of an understudied pVM82 plasmid present only in Y pseudotuberculosis sttains causing clinical-epidemic manifestation of the infec- tions as Far East scarlet-like fever (FESLF). The data obtained on the ability of far-eastern strains to produceYPMa super-antigenj Ypseudotuberculosis-derivative mitogenA, probablygive evidence on its key role in FESLF pathogenesis.
View Article and Find Full Text PDFKlin Lab Diagn
January 2016
The neutrophilic granulocytes were traditionally considered exclusively as phagocytes - killer cells of microorganisms invaded human organism. The discoveries of last decade permitted to significantly reconsider this role and importance of neutrophils in implementation of affect mechanisms of inherent and adaptive immunity. The modern achievements expanded our conceptions about anti-microbial strategies of neutrophilic granulocytes under infection pathology: phagocytosis, degranulation and development of neutrophil extracellular traps.
View Article and Find Full Text PDFMetabolic activity of innate immunity cells infected by various doses of Gram-negative (Yersinia pseudotuberculosis, Salmonella enteritidis) and Gram-positive (Staphylococcus aureus, Listeria monocytogenes) bacteria has been investigated. Using various animal models we found that during the initial period (up to 2 days) changes of infection in cellular responses depend on the type of the pathogen. In response to infection caused by Gram-negative bacteria predominant neutrophil accumulation in the foci of inflammation was observed, while Gram-positive bacteria induced preferential accumulation of macrophages.
View Article and Find Full Text PDFLow activity of bactericidal enzymes was found in innate immunity cells infected with S. pneumonia. The death of these cells was fastened under these conditions.
View Article and Find Full Text PDFThe thermolabile toxin of Yersinia pseudotuberculosis produces a selective dose-dependent stimulating effect on functional activity of innate immunity cells. Prolonged apoptosis-inducing action of the toxin was associated with activation of enzymes of the oxygen-dependent system (LDH and myeloperoxidase) at the early terms of observation (up to 3 h). In turn, increased number of macrophages with apoptotic changes was noted at the early stages of contact with the thermolabile toxin (5 h), and its further growth was observed against the background of activation of mitochondrial enzymes and production of NO metabolites.
View Article and Find Full Text PDFPathomorphological changes in the organs of animals intranasally infected with Streptococcus pneumoniae were studied under conditions of immunotropic therapy added to antibiotic therapy. The pathomorphosis in the lungs, spleen, and thymus in animals treated with likopid, tinrostim, and roncoleukin was described. A positive time course of the pathological process in experimental animals in comparison with intact animals and animals receiving no immunotropic drugs was demonstrated.
View Article and Find Full Text PDFFor the first time the nature of cell damages under pseudotuberculosis as a generalized infection has been analyzed by positions of the modern knowledge about types of the cell death. The own and literature data have pointed to presence the apoptosis-induced effect of Yersinia pseudotuberculosis, a causative agent of this infection. In conclusion, the typical pathological changes for pseudotuberculosis infection such as granuloma formation with the central karyorrhexis could be appearance of apoptotic and secondary necrotic changes.
View Article and Find Full Text PDFWe studied the role of Y. pseudotuberculosis endotoxin (LPS) in the pathogenesis of hemostasis and microcirculation disorders. It was found that changes in the hemostasis system after injection of LPS had biphasic character corresponding to the stages of DIC syndrome development.
View Article and Find Full Text PDFIn stimulated status neutrophils and monocytes in the foci of introduction the different materials are capable to excrete of biologically active substances by means of which if influence on processes of reparation. The express changes of blood leukocytes activity in response on the introduction of stimulated agents are assume as a basis of the proposed model of the organism biocompatibility with different materials. On example of the influence of different materials (ceramics, titanium, latex, surgical steel and copper), from which can be made implant and surgical instruments it was showed that the leukocytes were showed the different reaction of enzyme systems.
View Article and Find Full Text PDFThe reactivity of oxide-dependent and nitroxide-forming enzymatic systems of macrophages infected by bacteria, characterized by intraphagosomal (Staphylococcus aureus) and intracytoplasmatic (Listeria monocytogenes) localization in the phagocyte has been investigated. The correlation analysis revealed links between indices of the activity of oxide-dependent and nitroxide-forming enzymatic systems of infected macrophages.
View Article and Find Full Text PDFThe metabolic activity of macrophages infected with tick-borne encephalitis virus (TBEV) affecting the human nervous system has been studied for the first time. The penetration and reproduction of TBEV in the macrophages stimulated their oxygen metabolism, increasing the activity of NADPH-oxidase complex, as well as the mitochondrial enzymes lactate dehydrogenase, succinate dehydrogenase, and cytochrome oxidase. A wave-like change in the activity of these enzymes in the macrophages reflected the reaction of the cells to the penetration of the virus in the first period (within 3 h) and to the synthesis of the virus particles and their exit into the extracellular space in the second period (from 5 to 48 h).
View Article and Find Full Text PDFZh Mikrobiol Epidemiol Immunobiol
May 2006
The analysis of the functional and enzymatic activity of mouse peritoneal macrophages contaminated with Staphylococcus aureus and Listeria monocytogenes virulent strains is presented. The low bactericidal and digestive activity of these cells with respect to the above-mentioned microorganisms was determined. In this study a decrease in the activity of plasmatic membrane enzymes (5'-nucleotidase and ATP-ase) of macrophages contaminated with S.
View Article and Find Full Text PDFMonocytes/macrophages are one of the first cells subjected to the infectious effect of viruses. The present paper analyses for the first time the ultrastructural changes in macrophages caused by an agent of hemorrhagic fever with renal syndrome (HERS)--hantavirus (HV). After a local fusion with the host cell plasmalemma and its adsorption on the cell surface, the HV penetrates through the macrophage membrane.
View Article and Find Full Text PDF