Study of Viral Coinfection of the Ticks Feeding on Humans in a Natural Focus of the South of the Far East.

The phenomenon of pathogen co-infection detected in a half-fed tick taken from a human in the south of the Far East was studied. Research was carried out on , , and cell lines, outbred mice, and chicken embryos using ELISA, PCR, IMFA, plaque formation, and electron microscopy. The tick contained an antigen and a genetic marker of the tick-borne encephalitis virus (TBEV).

Ultrastructure and Morphological Variability of Non-Culturable Forms of Yersinia pseudotuberculosis Bacteria.

One 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.

Biosensor Technologies in Medicine: from Detection of Biochemical Markers to Research into Molecular Targets (Review).

Infections are a major cause of premature death. Fast and accurate laboratory diagnostics of infectious diseases is a key condition for the timely initiation and success of treatment. Potentially, it can reduce morbidity, as well as prevent the outbreak and spread of dangerous epidemics.

Ultrastructural Changes of Bacteria in Static Cultures of Yersinia pseudotuberculosis under Long Storage under Conditions of Low Temperature.

Electron 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.

Far Eastern Scarlet-Like Fever is a Special Clinical and Epidemic Manifestation of Infection in Russia.

Pseudotuberculosis in humans until the 1950s was found in different countries of the world as a rare sporadic disease that occurred in the form of acute appendicitis and mesenteric lymphadenitis. In Russia and Japan, the () infection often causes outbreaks of the disease with serious systemic inflammatory symptoms, and this variant of the disease has been known since 1959 as Far Eastern Scarlet-like Fever (FESLF). Russian researchers have proven that the FESLF pathogen is associated with a concrete clonal line of characterized by a specific plasmid profile (pVM82, pYV 48 MDa), sequence (2ST) and gene allele (1st allele).

Cell geteromorphism in the conditions of persistence of sapronoses causative agents in various environments.

The paper discusses the issues of morphofunctional variability of causative agents of sapronoses under stressful environmental conditions. In the current century, sapronoses infections attract more and more attention. Under unfavorable habitat conditions, their pathogens use a strategy for the formation of resting (stable) states: viable but non-cultured cell forms and the persistence of bacteria, which are characterized by reduced metabolism, changes in the morphology and physiology of microorganisms, and termination of their replication.

Toxin-Antitoxin Systems and their Role in Maintaining the Pathogenic Potential of Causative Agents of Sapronoses.

In interepidemic periods, causative agents of sapronoses typically employ a variety of mechanisms for maintaining the viability in terrestrial parasitic systems, associated with different adaptive strategies and utilized by their populations to survive. Unlike spore-forming bacteria, causative agents of sapronoses form resistant cell forms: viable but nonculturable (VBNC) cells and persistence (dormant) cells. The implementation of these strategies is mediated by the influence of various stressors of the environment and is characterized by a decrease in metabolism, a change in the morphology and physiology of the bacterial cell, and also the cessation of its replication.

[Pathomorphism of Hantavirus infection under prolonged heat stress].

Aim: to provide the morphological characteristics of experimental Hantavirus infection under heat stress conditions to identify the possibilities of its modeling in resistant laboratory animals.

Material And Methods: Experiments were carried out on outbred albino mice that were divided into 4 groups: 1) intact mice unexposed to heating; 2) those exposed to heating; 3) Hantavirus-infected animals unexposed to preheating; 4) those exposed to preheating. The animals in Groups 2-4 were long exposed to heat stress at a temperature of 30 °C for 3 hours during 3 days.

THE STRUCTURAL CHANGES OF MACROPHAGES INFECTED WITH TICK-BORNE ENCEPHALITIS VIRUS.

Macrophages belong to the innate immune cells and play a key role in the pathogenesis of viral infections. The results of ultrastructural study of macrophages infected with tick-borne encephalitis virus (TBEV), the Flavivirus family, pathogens of human infections, affecting the nervous system, were presented. With the assistance of virological methods was found that the TBEV are absorbed by macrophages and replication in them.

Morphogenesis of Experimental Infection Caused by Plasmid Variants of Yersinia pseudotuberculosis.

The 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.

[PLASMID-ASSOCIATED VIRULENCE OF YERSINIA PSEUDOTUBERCULOSIS AND INFECTIOUS PROCESS].

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.

[Antiviral action and pathogenetic targets for seaweed sulfated polysaccharides in herpesvirus infections].

The review summarizes results of studies of effects of sulfated polysaccharides from seaweed on herpesviruses and the course of herpesvirus infections. Importance of this problem is determined by the prevalence of herpesviruses that can persist in the human body and demonstrate a high degree of immune mimicry and resistance to antiviral agents. A wide range of physiological action of sulfated polysaccharides, receptor agonists of innate and adaptive immune cells, which possess potent antiviral, antioxidant and anti-inflammatory activities, open the possibility of their use for creation of new generation pharmacological substances and agents with associated activity for the treatment of herpesvirus infections.

[The antimicrobial strategies of neutrophils under infection pathology.].

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.

[The metabolism of the innate immunity cells in bacterial infections].

Metabolic 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.

Effects of immunomodulators on functional activity of innate immunity cells infected with Streptococcus pneumoniae.

Low activity of bactericidal enzymes was found in innate immunity cells infected with S. pneumonia. The death of these cells was fastened under these conditions.

Review: prospects for the use of extracts and polysaccharides from marine algae to prevent and treat the diseases caused by Helicobacter pylori.

Helicobacter pylori possesses a broad spectrum of pathogenic factors that allow it to survive and colonize the gastric mucosa, and thus, the pathogenetic targets, which have the same diversity, require search for and the development of alternative, effective, and innocuous means for the eradication of H. pylori. In recent years, fucoidans have been extensively studied due to the numerous interesting biological activities, including the anti-adhesive, anti-oxidative, antitoxic, immunomodulatory, anticoagulant, and anti-infection effects.

Effect of thermolabile toxin from Yersinia pseudotuberculosis on functions of innate immunity cells.

The 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.

Fucoidan extracted from Fucus evanescens prevents endotoxin-induced damage in a mouse model of endotoxemia.

An important problem of treating patients with endotoxemia is to find drugs to reduce the negative effects of endotoxin on the organism. We tested fucoidan (sulfated polysaccharide) from the brown alga Fucus evanescens as a potential drug in a mouse model of endotoxemia inducted by lipopolysaccharide (LPS). The survival time of mice injected with LPS increased under fucoidan treatment compared with the group of mice injected with LPS only.

Pathomorphosis of experimental infection in mice, infected by Streptococcus pneumoniae, under the effect of immunotropic drugs.

Pathomorphological 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.

Morphological validation of hydroxyethylstarch use during the acute period of severe brain injury.

The effects of 10% hydroxyethylstarch solution on the cerebral microcirculatory bed and the blood-brain barrier were studied in Wistar rats during the acute period of severe brain injury. Positive changes in the morphometric values of the cerebral capillaries were observed in animals receiving intravenous injections of the drug, which promoted reduction of vascular permeability and cerebral tissue edema. These results confirmed the efficiency of hydroxyethylstarch as a component of infusion therapy in patients with severe brain injury.

[Neuroprotective effects of sulfated polysaccharides from seaweed].

Currently, neurodegenerative diseases (NDD) occupy a significant place in the structure of disease of the elderly, which dictates the need to find new and effective treatment and prevention of this pathology. At the heart of NDD development is a violation of the metabolism and the conformational change of cellular proteins with subsequent accumulation and aggregation of their in certain groups of neurons. The immediate cause of the death of the affected neurons in NDD is initiated by intracellular proteins apoptosis, during which a large number ofneurotransmitter glutamate is released.

[Biochemical markers of virus cytopathogenicity in macrophages].

The results of macrophage metabolism studies at their infection by viruses differing in the level of virulence are presented. With the purpose of optimizing the estimation of viral cytopathogenic effects on macrophages, an index of cell reactions, which allows one to reveal the degree of virus influence in standard units, is offered. Generally, the application of high-sensitivity methods for functional activity determination and identification of the correlative communication between its changes and morphological features of cells can be prescribed to objective identification methods of not only viral reproduction, but also differentiation of types and the degree of their cytopathogenic effects.

[The physiological role of nitric oxide in infectious process].

This review presents the recent data on the physiological role of the molecule nitric oxide (NO) and its derivatives in the pathogenesis of bacterial and viral infection. Indicated that the effect of NO on individual cells involved in inflammation and immune regulation may be ambiguous, and depends on the cellular environment on the concentration NO and other factors. Thus, the interaction between reactive oxygen and NO derivatives provides a molecular basis for synergy between the respiratory burst and synthesis of NO, which leads to the formation of peroxynitrite, which has powerful bactericidal potential.

[The new views to pseudotuberculosis pathology].

For 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.

Neutrophil apoptosis induction by tick-borne encephalitis virus.

Tick-borne encephalitis virus infects neutrophils and induces their apoptosis, judging from moderate increase of succinate dehydrogenase activity and a trend to anaerobic energy production in neutrophils infected with the virus (shown by an increase of lactate dehydrogenase activity).