PATHOMORPHOLOGICAL CHANGES IN LIVER OF WHITE MICE AT EXPERIMENTAL PLAGUE INFECTION CAUSED BY YERSINIA PESTIS OF DIFFERENT PLASMID COMPOSITION

Data of histological study of pathomorphological changes in liver of white mice with experimental plague are represented in the article. An important element in evaluation and prediction of the pathological process in the liver is the analysis of hepatocyte karyokinesis, the mitotic index calculation, the counting number of atypical mitosis and the degree of organ regeneration ability. Dynamics of these liver changes at infection process in experimental animals caused by Yersinia pestis plasmid variants was investigated in this work. The variability of liver injuries was shown depending on plasmid-associated virulence of the infection agent. It was proved that the Y. pestis strain carrying three basic pYP (6 mDa), pYV (45 mDa), pYT (61 mDa) plasmids caused the most severe systemic disease with lethal outcome as a rule. Lack of species-specific plasmids and especially virulence and pathogenicity plasmids reduced the rate of infection process generalization and the ability of the pathogen to initiate pathological changes incompatible with the microorganism life. Therefore, all morphological liver changes in experimental plague infection are directly dependent on plasmid profile of the pathogen. The mechanism of toxicity included the damaging effect of the toxin to the cellular structures and failure of the metabolic processes in the organism. Acuity of intoxication and the development of pathological process can be estimated by exploring changes in liver morphology

Changes in cellular components of peritoneal fluid of white mice with infection caused by Yersinia pestis with different plasmid profile

The article presents the data on the influence of Yersinia pestis plasmid profile on subpopulation structure of mononuclear cells of peritoneal fluid of mice at the early stages of infectious process. It was showed that change of cellular composition of peritoneal fluid of the experimental animals depended on the plasmid profile of Yersinia pestis strains. The phase character in the changes of quantitative composition of the mast cells of peritoneal fluid of white mice infected with Y. pestis strains with different plasmid spectrum was determined

Pathoanatomical Pattern of Brain Damage of White Mice Infected with Experimental Anthrax

Background. Bacillus anthracis is a microorganism that causes anthrax. Because of irrational therapy, this particularly dangerous infectious disease leads to a systemic spread of bacteria in the body through histohematological barriers. Bacilli entering the brain subsequently lead to hemorrhagic meningitis. Despite intensive antibiotic therapy, that kind of meningitis is difficult to cure and therefore highly lethal. Studying characteristics of anthrax’s isolates of different origin and genotype is an actual area of research.The aim of the study is searching for pathomorphological and histological changes in the brain regions of experimental animals with anthrax infection, caused by B. anthracis with different plasmid spectrum.Materials and methods: The study was conducted on 200 certified white mice, three B. anthracis strains were used as research objects: B. anthracis I-323 (рХО1– /рХО2– ), B. anthracis I-275 (рХО1- /рХО2- ), and B. anthracis I-217 (рХО1+ / рХО2– ). The material for histological examination was the brain of mice, embedded in paraffin, and then sections were prepared using a microtome and stained with hematoxylin-eosin and Nissl toluidine blue. The degree of neuronal damage was assessed by calculating the semi-quantitative factor and determining the average size of the neuron nuclei, and the numerical density of cells in 1mm2 was studied. Microphotography and quantitative analysis was performed using the Motic Images Plus 2.0 application package. Statistical processing of the results was performed using the program “Statistica 6.0”.The results of the study showed that the brain of infected mice shows signs of hemorrhagic leptomeningitis, the manifestations of which are more pronounced in mice infected with weakly virulent plasmid strains of B. anthracis and fallen mice.Conclusion. Multicomponent exotoxin and specialized proteins, encoded in the pathogenicity plasmid of microorganisms, allow B. anthracis to easily overcome histohematological barriers and cause severe septic anthrax. The results obtained during the study supplement the available information on the pathogenesis of anthrax and indicate the need for further research in this direction

Characteristics of an antioxidant activity of Yersinia pestis with different plasmid spectrum

Experimental data concerning complex study of antioxidant activity of Y. pestis with different plasmid spectrum (wild-type Yersinia pestis subsp. pestis, Yersinia pestis subsp. altaica and their isogenic variants) are represented in the article. Superoxide dismutase activity of the tested Y. pestis strains was from 6.0 to 9.0 x 109 microbe cells. Significant differences between the Y. pestis strains with different plasmid composition were not detected by this parameter. Our results, consistent with the data of other authors, tell that superoxide dismutase activity is a thermo-inducible feature and does not depend on a plasmid spectrum. High peroxide destroying activity was also detected in all tested Y. pestis strains. The differences between the strains regarding their common peroxide destroying activity were found. This parameter of the plague microbe strains lacking pYP plasmid was at least 3 times lower than common peroxide destroying activity in strains with this plasmid in the genome. In our opinion these revealed differences were caused by characteristics of plasmid spectrum. The common peroxide destroying activity's degree of Y. pestis strains can be associated with the presence of pYP plasmid in the genome. The isogenic variants of Y. pestis strains lacking one of the plasmids had smaller pathogenic activity. This fact points to the need for further study of these strains

Studying of immunophysiological properties of Yersinia Pestis strains with various plasmid composition

Data of Yersinia pestis plasmid structure influence on its adhesive properties and phagocytic activity of peritoneal macrophages in vitro are represented. It is shown that Y. pestis strains of diverse subspecies differing by a plasmid profile, particularly by one of the plasmids (pYP, pYV) lacking, possess low adhesive activity and promote the increase of laboratory animal phagocyte absorbing capacity

Structural rearrangement of organs of white mice vaccinated with Yersinia pestis EV in combination with organoselenium compound 974zh

Introduction. An urgent direction is the search for means that increase the effectiveness of the Y. pestis EV NIIEG vaccine and reduce the side pathological manifestations caused by it. Organoselenium compounds have immunotropic properties and increase the antioxidant potential of the body, as well as have an antidystrophic effect and an antiallergic effect. Materials of the study of the immunomodulating effect of the experimental selenium-containing compound 2,6-dipyridinium-9-selenabicyclo[3.3.1]nonane dibromide (974zh) on the macroorganism of laboratory animals are presented.The aim. To evaluate the effect of the organoselenium compound 974zh on the structural rearrangement of the organs of experimental animals in the dynamics of the vaccine process caused by Y. pestis EV.Methods. The study was carried out on 70 certified outbred white mice. Histological material (thymus, lymph nodes, spleen, adrenal glands, liver) was embedded in paraffin, semi-thin sections were stained with hematoxylin and eosin, thionin, and by the Brachet method. The severity of pathological changes in the liver and adrenal glands, proliferation of plasma cells and structural changes in immunocompetent organs (thymus, lymph nodes and spleen) were assessed. Microphotography and quantitative analysis were performed using MoticImagesPlus 2.0. Statistical processing was carried out using the computer program Statistica.Results. It has been established that the combined administration of 974zh and Y. pestis EV leads to morphological and functional restructuring of immunocompetent organs, enhances the proliferation of plasma cells in the spleen and lymph nodes, and eliminates negative changes in the liver and adrenal glands. Conclusion. Thus, the 974zh preparation enhances the immunogenic effect of the Y. pestis EV vaccine strain, increasing the T- and B-dependent zones of the spleen and lymph nodes, increasing the proliferation of plasma cells, and also significantly reduces pathological changes in the liver and adrenal glands

Sanitary-Hygienic and Microbiological Monitoring over the Water Supply Sources and Surface Water Reservoirs during Natural Disaster in the Amur-River Territory

Emergency situation in summer 2013 due to flooding of extensive areas of the Russian Amur-River territories (including residential areas with different level of development of public services and amenities, agricultural land, sites of cattle grazing and stock-keeping) resulted in the increased microbiological, virologic and physical-chemical load upon water reservoir ecosystems. The results of monitoring over water supply sources, quality of drinking water and surface reservoir waters in the devastated territories were analyzed by the specialists from Rospotrebnadzor and specialized anti-epidemic teams No. 1 and 2. Complex approach presuming increase in extent and frequency of the examinations, performance of operative epidemiological analysis along with daily adequation of preventive and anti-epidemic measures allowed for taking control over the situation and to avoid epidemic complications as regards acute water-borne intestinal infections

Pathological Changes in Respiratory Part of Lungs White Mice with Experimental Plague

The paper presents data on changes in the respiratory part of lungs of white mice with experimental plague caused by Yersinia рestis strains with different plasmid composition of Tuva and Gorno-Altaisk natural foci of plague and breeding clones. Morphological and structural changes in the lungs, which appear different degree of activation of the immune response and the severity of the pathological process caused by Y. pestis subsp. altaica and Y. pestis subsp. pestis and their isogenic plasmid options

Immunophenotyping of Blood Cell Subpopulations from Experimental Animals Infected by Yersinia Pestis with Different Plasmid Composition

Relevance. The vast majority of the virulence factors of Yersinia pestis is determined by genes of plasmid. The genome of the plague pathogen Altai subspecies Y. pestis subsp. altaica has three plasmids: pYV, pYP and pYT. Plasmids pYV Yersinia strains exhibit phenotypic traits, the effect of which is aimed at the suppression of the phagocytic activity of the cells of the immune system. Species-specific plasmid pYP determines synthesis bacteriocine (pesticin 1) and plasminogen activator, and plasmid pYT - murine toxin and a capsular antigen F1. Loss of one or more plasmids leads to a change of the pathogenic properties and a reduction or even total loss of the virulence of the pathogen, as well as affect the functional state organs of the immune system. Goal. To reveal characteristics of subpopulations of blood cells of experimental animals infected with Y. pestis containing various plasmids Materials and methods. The study was conducted on 370 white improved conventional mice with standard of content and weight (17 -19 g). As objects of study used 7 strains of Y. pestis from the collection of the museum of living cultures of the Irkutsk Scientific Research Anti-Plague Institute: Y. pestis subsp. altaica I-2948/3, Y. pestis subsp. altaica I-2948, Y. pestis subsp. altaica I-2359, Y. pestis subsp. I-3560 pestis, Y. pestis subsp. I-3480 pestis, Y. pestis subsp. I-2638 pestis, Y. pestis subsp. pestis I-3479. Results. Immunograms analysis showed that changes in the composition of blood cells in experimental animals depends on plasmids of the strain and time of observation. Importantly, the infectious process induced strains with a complete set of plasmids (Y. pestis subsp. pestis I-3560, Y. pestis subsp. pestis I-2638), is accompanied by significant changes in cell populations, as the causative agent of plague blocking barrier system key mechanisms innate immunity and prevents the formation of high-grade microorganism adaptive immunity. Conclusions. Are established features of subpopulation structure of blood cells of white mice, infected with strains of the main and Altai subspecies and their isogene options which are associated with a plasmid profile of a plague microbe. Strains of Y. pestis subsp. pestis of I-3479 and Y. pestis subsp. pestis of I-3480 can be recommended for further studying as perspective as vaccinal

Comparative Evaluation of Proteolytic and Superoxide Dismutase Activities of Yersinia pestis Strains with Different Plasmid imposition

Data of the proteolytic and superoxide dismutase activities of Yersinia pestis strains with different plasmid spectrum are presented. It was established that superoxide dismutase activity of the tested Y. pestis strains was not associated with its plasmid composition. Some differences were revealed concerning the proteolytic activity. Direct dependence of proteolytic activity level of the studied Y. pestis strains on pYV plasmid presence in its genome was found