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N D Konstantinova

Publications and source records attributed to N D Konstantinova.

At least 19 recordsLinked to original sources
PubMed1992

[Pseudomonads as parasites of protozoa].

The experimental study of the interaction of Tetrahymena pyriformis with different microorganisms of the genus Pseudomonas, isolated from the soil, was made. The study revealed that T. pyriformis phagocytosed some Pseudomonas pigment-forming species (P. cepacia, P. putida, P. fluorescens, P. pirkettii). The most pronounced cytopathogenic effect was produced by P. cepacia. The dynamic observations of the ultrastructural features of interaction between P. cepacia and protozoa were made. Even at early stages of this interaction some types of parasitiferous phagosomes containing both intact bacteria capable of multiplication by binary division and Pseudomonas cells exhibiting different degrees of destruction were registered. In several phagosomes morphologically intact bacteria differing in their cell-wall profiles and the density of their cytoplasm and nucleotide were present simultaneously. More dense cells with sinuous cell-wall membranes were more virulent. By hour 18 one giant parasitiferous vacuole was formed by fusion of smaller phagosomes, which subsequently broke up, liberating a new generation of bacteria. In infected cells disturbances in the structure of their mitochondria and macronucleus appeared. During the first 2 days of the joint cultivation of P. cepacia and T. pyriformis the accumulation of bacteria occurred due to the selection and multiplication of digestion-resistant bacterial cells, which ensured the resistance of this Pseudomonas population in association with protozoa.

Animals↗
PubMed1991

[The ultrastructural characteristics of the interaction of Legionella pneumophila with the infusorian protozoon Tetrahymena pyriformis].

In this work the morphological features of the interaction of L. pneumophila virulent strain and T. pyriformis have been studied on the submicroscopic level in the time course of the process. The study has shown the process of the destruction of the bacterial population and the penetration of individual intact Legionella cells from the phagosome into the endoplasm of T. pyriformis after 6-9 hours of interaction in the form of the budding of the phagosome and further multiplication of Legionella in the endoplasm. As revealed in this study, T. pyriformis have two types of phagosomes characterized by different variants of the destruction of Legionella. In T. pyriformis lysosomes-like granules, mitochondria and the granular endoplasmatic network take part in the process of interaction. The process of interaction has been found to end by day 7 in the death of all protozoal cells taking part in interaction.

Animals↗
PubMed1990

[An analysis of the mechanisms of interpopulation interaction of Yersinia with Tetrahymena pyriformis infusorians at the cellular and subcellular levels].

The mechanisms of interaction between the populations of Yersinia and T. pyriformis have been analyzed on the cellular and subcellular levels. As shown in this investigation, Yersinia, when phagocytized by T. pyriformis, may undergo morphological changes, remain unchanged and also multiply, destroying the host cell in the process.

Animals↗
PubMed1990

[The combined action of microwave radiation and hydrogen peroxide on the viability and ultrastructure of Pseudomonas aeruginosa cells].

The comparative study of the action of microwave radiation and hydrogen peroxide, as well as their combined action, on the viability and ultrastructure of P. aeruginosa cells has been made. The combined use of microwave radiation and hydrogen peroxide has been shown to decrease the viability of P. aeruginosa 1.5-2 times in comparison with the isolated action of each factor. The electron microscopic study of the ultrastructure of cells have shown the deterioration of the surface structures, nuclear and ribosomal apparatus of the cells under the isolated action of each of the above-mentioned factors or under their combined action. The morphological picture of these changes has proved to be different. The maximum changes in the ultrastructure of P. aeruginosa cells have been registered after the combined action of these bactericidal factors.

Colony Count, Microbial↗
PubMed1989

[Outer membranes of Francisella tularensis and their protein composition].

Four strains of the species Francisella tularensis were used in the present work: a live vaccine strain 15/10 and three virulent strains (503, Schu, 543) from three different subspecies. The bacterial membranes were prepared by the 0.5% N-laurylsarcosinate (Sarcosyl) treatment. These membranes were identified as the outer membranes by morphological, immunological and biochemical analyses. The outer membrane proteins contained up to 30-35 polypeptides with three dominant fractions having the 63, 48 and 41-43 kD molecular masses. Despite the significant similarity between the membranes protein profiles there were some quantitative and qualitative differences between the three variants of Francisella tularensis in polypeptides compositions and patterns.

Bacterial Outer Membrane Proteins↗
PubMed1989

[Dissociation and ultrastructure of the cells of Shigella sonnei isolated from gnotobiotes and obtained in vitro].

The dissociation variants of S. sonnei in phase I, isolated from germ-free rats and obtained in vitro, have been studied. Such dissociation variants have been found to form colonies with classical and atypical morphology. The electronmicroscopic study has revealed that different dissociation variants include small dense cells with the markedly thickened cell wall and pronounced microcapsule and spheroplasts with the damaged cell wall and less pronounced microcapsule. The formation of these cells is supposed to be the way of the adaptation of S. sonnei in the course of the infectious process and linked with changes in their virulence in the population cycle.

Animals↗
PubMed1988

[Isolation and ultrastructure of Yersinia spheroplasts and protoplasts].

The conditions suitable for the cultivation of Yersinia and the inhibition of their cell-wall synthesis have been selected with the aim of obtaining spheroplasts and protoplasts of these microorganisms. Penicillin, streptomycin and lithium chloride have proved to be not very suitable for this purpose as they induce essential changes in the structure of the cytoplasmic membrane in altered Yersinia forms. The addition of 1% of glycine (for Y. pseudotuberculosis), 1-1.5% of methionine in combination with growth stimulators has made it possible to obtain Yersinia spheroplasts and protoplasts with the intact cytoplasmic membrane, thus permitting the isolation and purification of the cytoplasmic membrane fraction.

Bacteriological Techniques↗
PubMed1987

[Ultrastructure of Staphylococcus in disruption of the integrity of the cell wall].

The effects of penicillin, lithium chloride and homologous antiserum with complement on S. aureus after a single exposure to these agents and in subsequent subculturing were studied. The viability of the altered forms obtained in these experiments was evaluated by the number of colony-forming units per ml. The action of all above-mentioned agents resulted in the appearance of staphylococcal forms with the altered cell wall. The lesions in the submicroscopic organization of the cell wall, produced by the action of the above-mentioned agents, differed in the appearance of porosity and ruptures in the wall under the action of penicillin and antiserum, thinning and peeling-off of the wall under the action of lithium chloride. The damage of the cell wall is accompanied by the disorganized septal development and mitosis, and sometimes by the formation of elementary bodies in the cytoplasm.

Cell Wall↗
PubMed1986

[Antibiotic resistance of revertant cultures of Streptococcus group A and of unclassified streptococci isolated from the blood of rheumatism patients].

Sensitivity of one strain of group A Streptococcus, its L-form and revertant was tested to 7 antibiotics and it was observed that the revertant was highly resistant to beta-lactam antibiotics and lincomycin, tolerant to ristomycin and had a high value of MBcC/MIC for erythromycin and tetracycline. Testing of other analogous revertant strains showed the same results. In streptococcal strains freshly isolated from blood of patients with rheumatism and resistant to some antibiotics there were recorded by electron microscopy heterogeneity of their population and presence in it of a significant number of cells with altered (unevenly thickened) cell walls and cells with microcapsules on the cell wall surface characteristic of the revertants. In vivo occurrence of streptococcal revertants may be the cause of their antibiotic resistance which obviously requires correction of the rational antibiotic therapy schemes.

Anti-Bacterial Agents↗
PubMed1985

[Isolation of unbalanced growth forms from Listeria and their ultrastructure].

As the result of the action of penicillin, LiCl and UV irradiation on Listeria culture in the logarithmic phase, unbalanced growth forms (UGF) were obtained. Their viability was determined by the number of colony-forming units per ml. In this investigation the action of the above factors in a single cultivation and in consecutive subcultures was studied. Viable UGF were obtained under the action of all the above factors. UGF obtained under the action of penicillin were found to convert easily into L-forms in the process of subculturing. On the contrary, UGF obtained under the action of UV irradiation and LiCl produced no L-forms and reverted easily when the action of these factors stopped. In all three cases the formation of UGF was accompanied by changes in the structure of the cell wall and, partially, the cytoplasmic membrane, but in each case these changes had different character.

Cell Division↗
PubMed1979

[Submicroscopic organization of M. pneumoniae studied by means of negative contrasting, ultrathin sections and scanning electron microscopy].

The ultrastructure of M. pneumoniae, grown on a solid culture medium and in a liquid one, was studied by a number of methods. Two types of cells were shown to prevail in the culture: spherical cells (0.5--1 micrometer) forming chains of different configurations and filamentous cells (5 micrometer long and greater) with spherical enlargements along their whole length. The absence of microcapsules made M. pneumoniae different from other species of mycoplasms, and the organism proliferated by division into 2 daughter cells, equal or unequal in size, by the segmentation of the cytoplasm and the formation of elementary bodies inside the cell and on its surface.

Bacteriological Techniques↗
PubMed1978

[Improving tetanus prevention in the Krasnodar area taking the current epidemic situation into account].

An increase of percentage of elderly persons among those who fell ill with tetanus (70%) was noted against a sharp reduction of tetanus incidence under the effect of mass active immunization against this disease. A study of immunity in older and elderly individuals showed the percentage of immune persons among them to be rather low (48.8--55.6%). Due to difficulty of elderly individuals embracement by vaccination the authors suggest a single immunization scheme with a double toxoid dose (20 BU) followed by revaccination with 10 BU in one year. A total of 21 472 persons were placed under observation. The suggested immunization scheme was harmless, promoted stimulation of antitetanus immunity in persons vaccinated earlier; as to unvaccinated persons--it created a favourable immunological preparedness for revaccination, permitting to do without any antitetanus serum in case of trauma.

Adolescent↗
PubMed1978

[Ultrastructure of the L forms of meningococcus].

The authors carried out an electron microscope study of the ultrastructure of the L-form of meningococcus. Several types of cells differing by shape, size, and electron density were revealed. Sharply angular cells closely adjacent to one another prevailed in the culture. Structureless material, possibly representing material of cellular wall was not infrequently revealed around the cells. Elemental bodies and membranous structures of the lamellar type were revealed within the cells.

L Forms↗
PubMed1978

[Structural study of Mycoplasma by a scanning electron microscopy method].

Scanning electron microscopy was applied to the study of Mycoplasma arthritidis, Myc. gallisepticum, and Acholeplasma laidlawii. Small spherical elements (0.3--0.5 micrometer) formed a reticular "framework" of the colonies in which larger (1--1.5 micrometer) spheroid or irregular-shaped cells (in case of Myc. gallisepticum) and also rod-shaped (1--3 micrometer), filamentous (3--5 micrometer) forms and "large bodies" (5 x 3--8 x 3.5 micrometer) were located. Apparently the latter represented conglomerates of adherent spheroid elements that resembled somewhat "large bodies" of L-forms. Small spheroid buds were revealed on the surface of all the elements.

L Forms↗