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V V Gosteva

Publications and source records attributed to V V Gosteva.

At least 19 recordsLinked to original sources
PubMed1991

Mixed Rickettsia-virus infection in Dermacentor reticulatus imago.

Electron microscopic examination revealed replication and accumulation of Rickettsia sibirica in the fat body of experimentally infected Dermacentor reticulatus ticks. Rickettsia are released from the fat body cells by budding being surrounded with cytoplasm and plasmalemma of the host cell. Eukaryotic cell structures have been detected consisting of lamella layers whirled around the intact rickettsiae. In addition to rickettsia, microorganisms morphologically resembling Francisella tularensis and an orbivirus were found in tick tissues at morphological examination. The morphology of the virus and stages of its morphogenesis are described. Mixed viral and rickettsial infection has been shown to develop in the same ticks and even in the same fat body cells in a very close association.

Animals↗
PubMed1991

[The ultrastructure of the interaction of Rickettsia sibirica and R. slovaca with the cells of ixodid ticks].

The ultrastructural aspects of the interaction of R. sibirica and R. slovaca with cells of mites of the species Dermacentor reticulatus, D. marginatus and Ixodes ricinus after their parenteral infection, as well as in the organs of D. marginatus infected naturally in the environment, have been studied. Both rickettsial species have similar morphology in different organs of the vector. These rickettsiae not only multiply, their populations are also partly destroyed in phagolysosomes. The natural mixed infection of R. sibirica and orbivirus in cells of D. reticulatus is described. As shown in this study, both associates pass through the complete ontogenetic cycle of development on the level of the host body and also on the level of an individual cell.

Animals↗
PubMed1990

[The surface antigens of Rickettsia prowazekii studied with monoclonal antibodies].

R. prowazekii antigens have been tested with the use of monoclonal antibodies (McAb) to different epitopes of the microorganism. As revealed in these tests, McAb B4/4 and A-3/D, active against species-specific thermolabile antigen, interact with protein having a molecular weight of 90-120 KD. McAb C5/2, active against thermostable group antigen common with that of Rickettsia typhi, interact with LPS-like antigen having a molecular weight of 30 KD. Ultrastructural immunochemical studies have revealed that both R. prowazekii antigens are located on surface structures of rickettsiae, such as the microcapsule and cell wall.

Antibodies, Monoclonal↗
PubMed1990

[The role of fibronectin in the pathogenesis of meningococcal infection].

We have characterized an interaction of 20 strains of Neisseria meningitidis serogroups A, B, C, 29E, W-135 and Z with immobilized fibronectin of human plasma. The adhesion of meningococci to fibronectin was determined by the extent of piliated cells and did not depend on the meningococcal serogroup. Binding of non-piliated or weakly piliated strains (2-5% of piliated cells in the stock) was sufficiently greater than those piliated (8-10%), where the adhesion to fibronectin was not at all observed. The examination of two well-piliated strains showed that the loss of pili resulted in the increase of bacterial adhesion to fibronectin. Constants of association and dissociation of piliated and non-piliated strains to fibronectin were calculated. The role of meningococci-fibronectin interaction in the pathogenesis of meningococcal infection is discussed.

Bacterial Adhesion↗
PubMed1989

[Change in the ultrastructure of the cell wall of Bacillus cereus, determined by RP4 MUCTS62 plasmid].

The influence of plasmid RP4 Mucts62, heterologous for B. cereus, on the growth rate of B. cereus strains GA 682 and 319 obtained in our earlier experiments and on changes in the ultrastructure of their cell walls in comparison with B. cereus initial strains GP 7 and DSM 318 has been studied. Plasmid RP4 Mucts62 with a wide spectrum of action has been found not only to determine the functional signs of resistance to antibiotics and thermal sensitivity in the heterologous host, but also to take part in the morphological organization of the cell surface structure, and in particular in the structure of the S-layer. B. cereus strains containing plasmid RP4 Mucts62 are characterized by slower growth rate and cell fragility.

Bacillus cereus↗
PubMed1989

[Adhesion in meningococcus].

The adhesive activity of 113 meningococcal strains with different invasive properties and 10 Neisseria nonpathogenic strains have been studied. Adhesive properties have been revealed in 80-82% of these strains. Meningococcal strains isolated from the nasopharynx of carriers possess high hemagglutinating activity. The percentage of cells with pili in these strain was also higher than that in meningococcal strains isolated from the liquor of patients. This shows the presence of direct correlation between the number of pili in the cells (according to the data of electron microscopy) and their activity in the hemagglutination test, which makes it possible to use this test for the determination of the adhesive capacity of meningococci, associated with the presence of pili.

Animals↗
PubMed1988

[Interaction of Neisseria meningitidis with eukaryotic cells in a mixed infection in vitro].

To study the adhesion of meningococci under the conditions of a monoinfection and mixed infection (in association with influenza virus), the experimental model of mixed influenzal and meningococcal infection has been created in the culture of epithelial cells HEp-2. On this model in increase in the intensity of the adhesion of meningococci to eukaryotic cells, as well as in the intensity of the meningococcal colonization of such cells, after their preliminary infection with influenza virus has been observed. The study has revealed that in mixed infection the adsorption of extracellular virions onto the surface of bacteria occurs. During this adsorption viral processes directly interact with the microcapsule of the meningococcus.

Adsorption↗
PubMed1987

[Ultrastructural characteristics of Proteus vulgaris and Proteus mirabilis cells differing in the capacity for swarming].

Specific differences in the structure of colonies and the location of microbial cells in colonies, characteristic for aggregating and nonaggregating genetically related pairs of P. vulgaris and P. mirabilis strains, have been demonstrated by means of transmission and scanning electron microscopy. In calculating the number of flagellae per 100 outlines of microbial bodies revealed in negatively stained preparations, the fact that both aggregating and nonaggregating bacteria possess practically the same number of flagellae, on the average 4-8 flagellae per microbial cell outline, has been established. This fact indicates that the presence of flagellae in microbial cells is unrelated to their capacity for swarming.

Cell Movement↗
PubMed1986

[Ultrastructural aspects of the process of Salmonella typhi bacterial interaction with L929-line cells].

The study of the use of scanning electron microscopy and the analysis of the initial stages of interaction between S. typhi and eukaryotic cells by the method of three-dimensional reconstruction has revealed that the infective agent penetrates into the cytoplasm on the principle of internalization. The internalization of S. typhi occurs with the active participation of the eukaryotic cells which, at the beginning, envelopes the bacteria with its processes, and the infective agents firmly adhere to the glycocalyx of the host cell by means of special fimbria-like formations differing from fimbriae by their lesser rigidity and thickness; then the microbes fixed to the membrane penetrate inside the cell without destroying its cytoplasmic membrane. Differences in the processes of the interaction of eukaryotic cells with S. typhi initial strain 238 and its variant free from the plasmid with a molecular weight of 6 Md, characterized by its lower capacity for association with cells of continuous cell culture L929, have been revealed. The factors stimulating the ingestion of S. typhi by eukaryotic cells are under study at present.

Adhesiveness↗
PubMed1984

[Klebsiella pneumoniae adhesion to epithelioid cells in vitro].

The adhesion of K. pneumoniae K24 capsular strain No. 6723 onto subcultured epithelioid human kidney cells RN was studied overtime by light microscopy and by transmission and scanning electron microscopy. To find out the bacterial capsule and glycocalyx of epithelioid cells, the method of staining the samples with ruthenium red was used, this stain producing the coloration of extracellular acidic mucopolusaccharides . The bacteria were found to attach to the qlycocalyx of epithelioid cells by means of protruding areas on the capsule which retained its form and size after both stabilization with ruthenium red and standard glutar -osmium fixation. Under the action of the bacteria epithelioid cells were found to round off, become longer and increase the number of processes. At the sites of contact with the bacteria specific short cytoplasmic processes serving for the attachment of K. pneumoniae cells were discovered.

Adsorption↗
PubMed1983

[Electron microscopic study of the interaction of nephritogenic strains of Escherichia coli carrying D-mannose-resistant fimbriae with the cells of a human kidney line].

The electron-microscopic study revealed that nephritogenic E. coli having L-mannose-resistant fimbriae contacted with subcultured human renal cells due to the interaction of fimbriae with microvilli and, less frequently, with the cytoplasmic membrane surrounding the main part of the cell, as well as with the electron-opaque fibrillar material in the intercellular space. The possibility of very close interaction was demonstrated; in some cases this interaction was so close that the outlines of bacterial and epitheloid cells followed each other, the invagination of the external membrane of the host cell being sometimes observed. The expediency of using ruthenium red for detecting fimbriae in morphological studies was shown. The cytopathogenic effect observed in this study and developing by the end of the 5-hour period from the moment of the inoculation of the monolayer with E. coli was manifested by the swelling of mitochondria accompanied by the partial ruptures of cristae, the widening of channels in the endoplasmic reticulum, the appearance of the secondary lysosomes and the increase of their number.

Cell Line↗
PubMed1983

[Bacterial adsorption on cultivated mammalian cells in conditions of mixed infection].

The method based on the use of 3H-labeled bacteria was applied to study the relationship between the magnitude of uropathogenic E. coli strain adsorption on mammalian cells in vitro and preinfection of the latter ones with virus. The presence of measles virus in cell culture raised the adsorption level of bacteria. Meanwhile oncoviruses did not alter the adsorption level. The possibility of generalized alterations of the cell surface by virus infection is discussed.

Adsorption↗
PubMed1981

[Streptococcus pneumoniae interaction with continuous human cell lines].

The in vitro model of pneumococcal infection, using continuous mammalian cell lines, is proposed. Two different types of interaction between bacteria and eucaryotic cells are described: the intracellular ingestion of bacteria or their proliferation on the surface of the cellular monolayer, these different types of interaction being characteristic of different cell lines. In case of the proliferation of bacteria on the surface of the monolayer the forms, morphologically similar to the stages of microbial L-transformation, have been detected.

Adsorption↗
PubMed1981

[Comparative study of the behavior of capsular and noncapsular pneumococcus variants in the L929 cell culture].

The comparative study of the behavior of the capsular and noncapsular variants of pneumococci, serotype 27, in culture L929 revealed that under the conditions of the experiment both variants showed the same capacity for adhesion, but the capsular variant had a stronger cytopathic effect which was retained after subculturing the infective material in the cell culture. The possibility of isolating the noncapsular variant of pneumococci from culture L929 on a solid nutrient medium lasted only 9 hours, while the capsular variant could be isolated during the whole experiment. The noncapsular variant showed greater sensitivity to the action of penicillin and more pronounced capacity for L-transformation in vitro than the capsular one.

Dose-Response Relationship, Drug↗
PubMedDate not supplied

[A surface membrane study of human cell lines with different interferon sensitivities].

A comparative study of surface membranes of human cell J-96 and J-48 cultures with different sensitivity to alpha/beta interferon (IF). Reduced sensitivity of J-41 cells to IF-alpha/beta was found to be accompanied by a loss of highly specific receptors for IF-alpha, the lack of changes in the cell surface structures upon treatment with IF-alpha/beta, reduced intensity of cell fusion upon successive treatment with IF and polyethylene glycol. The results are discussed in connection with the observed changes in the activity of superoxide dismutase in J-96 and J-41 cell lines after treatment with IF.

Cell Line↗
PubMedDate not supplied

[The multiple effect of plasmid RP4::Mu cts 62 in transcipient bacilli].

Transfer of conjugative hybrid plasmid RP4::Mu cts 62 from Escherichia coli into Bac. cereus, Bac. thuringiensis, Bac. mesentericus and Bac. polymyxa cells led to the multiple effects on the structure and physiology of bacillus cells. It has resulted in a decrease of the bacillus vitality, in the accelerated autolytic decay of cells, in the delay of cell growth and reproduction rate in liquid and solid media, in the disruption of ultrastructure of the cell membrane and its surface layer.

Bacillus↗