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N A Pereverzev

Publications and source records attributed to N A Pereverzev.

At least 19 recordsLinked to original sources
PubMed1990

[Characteristics of the damage to immunocompetent organs in experimental slow influenza infection].

Morphological changes in immunocompetent organs were studied in 30 mice with slow influenza infection. Histological, histochemical, and electron microscopy studies revealed destructive changes in different cell populations of the thymus and spleen. The changes were more pronounced in the reticuloendothelial cells of the thymus and endothelium of thymic capillaries. Complex examination helps to outline the general pathological patterns in interpreting the pathogenesis of experimental slow influenza infection.

Animals↗
PubMed1986

[Purification and properties of Bordetella pertussis toxin].

The modified method for the isolation and purification of B. pertussis toxin has been proposed. Chromatography with the use of hydroxylapatite and lentil lectin--Sepharose 4B has permitted the isolation of the preparation purified 600 times. Its molecular weight is about 90,000. The preparation has been found to possess leukocytosis-stimulating, histamine-sensitising and hemagglutinating activity. Electrophoretic analysis has revealed that the isolated substance consists of four subunits with molecular weights 28,400, 24,300, 21,800 and 15,200. This substance has proved to be capable of hydrolyzing NAD+, as well as of suppressing the GTPase activity of transducin, which is indicative of the covalent modification (ADP-ribosylyzing) of GTP-binding protein under the action of B. pertussis toxin. Two methods for the isolation of B. pertussis toxin (from liquid and solid growth media), as well as the isolation of the toxin from different B. pertussis strains, are evaluated.

Animals↗
PubMed1985

[Adhesion in Corynebacterium diphtheriae].

The study of 8 C. diphtheriae strains of different origin revealed that these strains were capable of inducing the agglutination of trypsinized sheep red blood cells (SRBC). Toxigenic strains gravis isolated from diphtheria patients were more active in their adhesion to SRBC than toxigenic strains gravis isolated from carriers. The latter were, in their turn, more active than nontoxigenic strains mitis. No fimbriae were detected on the cell surface by electron microscopy.

Adhesiveness↗
PubMed1984

[Characteristics of the ionic composition and ultrastructure of Bordetella pertussis in controlled regulation of the mineral element content in a growth medium].

The content of trace elements necessary for the normal growth of bacteria was found to have no effect on the intracellular concentration of Ca2+ and Al3+. The content of Cu2+, Fe3+, Mn2+, Mg2+ was considerably reduced. The addition of Mg2+ at different concentrations to this culture medium stimulated the capacity of cells for accumulating not only Mg2+, but also some other ions. Their maximum intracellular concentration was observed when the concentration of Mg2+ in the culture medium was 41 mM. The growth of microbial cells in the standard culture medium containing Mg2+ at a concentration of 4 mM was accompanied by the increased consumption of elements actively participating in redox reactions (Cu2+, Fe3+, Mn2+). Shifts in the ionic composition of microbial cells were manifested by the morphological features of B. pertussis, linked with the increased synthesis of crystalloid structures. The influence of Mn2+, Al3+, Zn2+ at different concentrations on the ionic composition and morphology of B. pertussis was studied.

Bordetella pertussis↗
PubMed1984

[Detection of Bordetella bronchiseptica strains containing the main agglutinogens of all species of the genus Bordetella].

The study of 26 B. bronchiseptica strains with typical morphological and biochemical properties resulted in the detection of 8 strains having the main specific agglutinogens of 3 Bordetella species (serovars) in different combinations. The presence of the agglutinogens was confirmed in the agglutination test and the agglutinin adsorption test with the use of monospecific antisera to the main agglutinogens. The comparison of natural B. bronchiseptica serovars and artificial convertants (resulting from the conversion of B. parapertussis by B. pertussis phages) revealed their identical biochemical activity, their capacity for causing necrosis when injected intradermally into rabbits and for the formation of two types of colonies, differing in size and serological activity. In contrast to B. parapertussis convertants, B. bronchiseptica serovars had no lysogenic properties and were sensitive to B. pertussis and B. bronchiseptica phages.

Adsorption↗
PubMed1981

[Effect of certain factors on the variability of strains of pertussis microbes].

The population of degraded cells having stable changes in some phenotypical properties were isolated after subculturing some laboratory Bordetella pertussis strains in Bordet-Gengou culture medium and casein-charcoal agar with blood, treated with mitomycin C and allowed to proliferate in the spleen of mice injected intravenously with microbial suspensions. The characteristics indicative of cell degradation were the growth of large yellowish-white colonies appearing in 24 hours, the destruction of the agglutinogenic complex and toxic substances causing the atrophy of the spleen in mice, the increased capacity for active proliferation in the spleen. Electron-microscopic study revealed that the variants obtained by subculturing in culture media had the damaged membrane with the formation of cell-wall invaginations having rounded membrane-like formations on their surface, disappearing after treatment with mitomycin C; the treatment of the initial strains with mitomycin C resulted in cytoplasmic damage with the coagulation of the nucleoid.

Agglutination↗
PubMed1980

[Bordetella pertussis bacteriophage].

For the first time Bordetella pertussis bacteriophage was isolated, and its presence was confirmed by electron microscopy and by agar layer titration. The lysogenic strains were activated by their treatment with mitomycin C in a dose of 4.5 mg/ml. The phage system of the Bordetella genus, heretofore unknown, has been revealed: Bordetella pertussis phage lyzed all the tested strains of Bordetella parapertussis (25 strains) and could be passaged in these strains. The phage formed turbid and transparent negative colonies 0.1 mm and 0.15 mm in size. The phage titer (e. g., in strain No. 3865) was 1 X 10(10). The lysogenic variants of Bordetella pertussis, capable of spontaneous release of the phage, were obtained. These variants were characterized by changes in some of their phenotypical properties, e.g., the increased content of certain toxic substances and increased virulence.

Bacteriophages↗
PubMed1978

[Identification and biological characteristics of strains of psychrophilic bacteria isolated from the diarrhea of polar research workers and from the water of Antarctic lakes].

Bacteria of Klebsiella genus and psychrophylic microbes affiliated by morphological and biochemical properties to Bac. psychrosaccharolyticus were isolated in bacteriological examination of diarrhea in 8 of 14 participants of the 12th Soviet Antarctic expedition. Psychrophylic bacteria isolated from the human intestinal contents possessed pathogenicity signs, i.e. these microbes liquefied gelatine, produced a cytotoxic action in the cells line Hep-2, and caused death of 50% chick embryos in infection with a dose of 5 X 10(8) bacteria.

Animals↗
PubMed1976

[New structural components detected in B. pertussis of different serotypes].

The authors present electron microscopic data on the study of morphological peculiarities of the strains belonging to various serological types. All the strains studied had a structure characteristic of Gram-negative bacteria. Two types intracellular membranes and intracytoplasmic crystal-like structures were revealed in a number of strains (No. 222, No. gZ353, No. 475), irrespective of the serological types. Dynamics of formation of the crystal-like structures in the bacterial cell was described. Marked changes occurred in the cells with the formation of crystal-like structures: cytoplasmic membrane became detached from the cell wall with the resultant contraction of the cytoplasm; large periplastic spaces formed.

Bordetella pertussis↗
PubMed1976

[Ultrastructure of B. pertussis using cryoultramicrotomy].

The authors pointed to a possibility of using the method of cryoultramicrotomy in studying the ultrastructure of Gram negative B. pertussis bacteria under the following conditions: a) fixationwith a 5% glutaraldehyde on cacodylate buffer (pH 7.5) for 30 min; b) replacement with a 30% dimethylsulfoxide in distilled water with a subsequent embedding of the material into tissue-tek; c) freezing in fluid nitrogen for 5 min; d) cutting at a temperature of -- 90% degrees C and at the temperature of glass knife of -- 40 degrees C, the knife angle of alpha = 45 degrees, beta = 6 degrees, and the cutting velocity of 5 mm/sec; e) placing of sections on copper grates covered with a 0.1% moulding membrane; d) contrasting with a 2% phosphotungstic acid queous solution (pH 7.5) for 5 sec and with a 3% uranil acetate on water for 5 min. Use of the mentioned method pemitted to detect structures localized in B. pertussis cytoplasm and also to trace the dynamics of their formation.

Bordetella pertussis↗
PubMed1976

[Isolation of various structural elements of gram-negative bacteria of the Bordetella genus and a study of their properties. II. Isolation of the cytoplasmic membrane fraction from the protoplasts of B. pertussis and a study of their chemical and enzymatic properties].

A possibility of obtaining a fraction of cytoplasmic membranes maximally purified of the cell wall material was for the first time shown on a model of Gram negative bacteria (B. pertussis). The results of electron microscopy, chemical analysis for the presence of the cell wall material--hexosamines, and of the activity of the respiratory chain enzymes served as control.

Bordetella pertussis↗
PubMed1976

[Vaccine from the cell fragments of Bordetella pertussis. I. Protective, sensitizing properties and morphological characteristics of the vaccine].

The authors present the results of studying the protective and sensitizing properties of a new preparation made of a ultrasonic disintegrate of pertussis microbes treated by ethyl ether. As shown by electron microscopy, the preparation consisted of the cell wall elements (the membrane), remnants of the cytoplasm and protectosome, i.e. it represented a vaccine consisting of cell fragments. In crude and sorbed condition it possessed marked protective properties (a test on mice). The content of protective units in the adsorbed preparation increased 1.5-3 times. The vaccine produced no sensitizing action, and its histamine-sensitizing activity was 3-5 times lower by protein and 5-10 times--by IOU than that of the whole-cell vaccine prepared form the same microbial suspension.

Animals↗
PubMed1975

[The role of the ability of Sh. flexneri to synthesize pili of the common type in the development of dysenteric infections].

HEp-2 epithelial cells infected with isogenic Sh. flexneri strains characterized by capacity to synthesize common pili (confirmed by electron microscopy) were studied. It was shown that although pili promoted an earlier adhesion of shigellae to the cells, they were not very significant for the penetration and intracellular development of dysentery bacilli in the epithelium. The use of bacteria labeled with 3H-glucose offers a possibility of an objective rapid and precise determination of the capacity of the microbes to adhere to the cell surface.

Animals↗
PubMed1975

[Isolation of the individual structural elements of bacteria of the genus Bordetella and a study of their properties. I. The formation of mureinoplasts and true protoplasts from B. pertussis].

B. pertussis suspension was tested by De Voe et al. method (1970) and its modification with the solutions of a definite ionic composition and a lysozyme. The best results were obtained by the following modification elaborated by the authors. The microbes were grown on the casein-carbon agar for 36 hours and were washed with chilled 0.5 M NaCl. The suspension was washed 4 times with the same solution and then the precipitate was suspended in saccharose solution (0.5 M). In 2 hours the saccharose was replaced by a solution of salts with lysozyme. After a 2-hour incubation at 35 degrees C the substance was centrifugated for 20 minutes and the precipitate suspended in the tris-buffer at pH 7.8. The following changes were observed: after the washing and incubation with saccharose there was seen a strong stretching and separation of the cell wall (CW) from the cytoplasmic membrane (CPM); cells without the CW were rarely revealed; 2) after the lysozyme treatment there were many cells of spherical shape (phasic-contrast microscopy) without any CW, limited by the CPM only. Morphologically they were no different from the true protoplasts of the Gram-positive bacteria. The chemical analysis also confirmed a possibility of obtaining the true protoplasts of the Gram-negative bacteria.

Bordetella↗