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L N Kats

Publications and source records attributed to L N Kats.

At least 19 recordsLinked to original sources
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↗
PubMed1987

[Ultrastructure of the L forms of Streptococcus group B].

The submicroscopic organization of the L-forms of beta-hemolytic streptococci of group B has been studied in the course of their cultivation. The L-forms of group B streptococci differ from those of group A streptococci by a higher growth rate. On the submicroscopic level, the activity of ATP-ase has been revealed on the internal side of the cytoplasmic membrane. Regularities in the localization of intramembranous particles sized 6-18 nm in the hydrophobic area of the membrane have been established by means of freezing-etching. With the adequate methods of fixation, the continuous three-layer structure of the cytoplasmic membrane can be determined in all elements of the L-form population.

Adenosine Triphosphatases↗
PubMed1986

[Comparative biological characteristics of the L-form of Streptococcus group A and B].

The comparative study of the biological and serological properties of the L-forms of streptococci, groups A and B, has been made. Their morphological similarity on the level of light microscopy has been demonstrated. The use of ring precipitation, gel diffusion, passive hemagglutination, aggregate hemagglutination, as well as the immunoferritin technique, has made it possible to establish the presence of specific antigens in the L-forms of streptococci, groups A and B. Serological cross reactions are negligible. The future development of a diagnosticum for the specific indication of these antigens is proposed. The fact of the presence of specific antigens in the L-forms of streptococci in comparison with the initial streptococcal strains has been confirmed.

Antigens, Bacterial↗
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

[Cell structure and the pathogenicity of Brucella at different stages of L transformation].

On the basis of changes in the biological properties and morphology of Br. abortus culture under the action of penicillin 3 stages of L-transformation in Brucella were determined. The prevalence of first bacilliform and then typical L-cells and rapid reversion hampering the determination of virulence were characteristic of the initial stage (passages 1-4). Typical L-cells with the wrinkled surface, deep depressions and holes as well as a decrease in virulence and slight pathomorphological changes in the organs of the infected animals were characteristics of the intermediate stage (passages 5-10). Typical L-cells and amorphous masses, a further decrease in virulence, pathomorphological changes of toxic character (only after the injection of L-culture in large doses) were characteristic of the late stage (from passage 11 and further on). At all stages of L-transformation Brucella cultures showed a high reproductive capacity, binary division, the formation of elementary bodies by budding both inside and on the surface of L-cells.

Animals↗
PubMed1979

[Population of L-forms of Bacillus subtilis studied in Ficoll density gradients].

The distribution of cells in the population of L-forms of Bas. subtilis was analysed by isopicnic centrifugation in density gradient of ficoll. Two main fractions of L-forms different in their density were found. The study of the fractions by various methods indicated that a considerable part of the L-forms population is presented by unviable cells of diverse size with fragments of genome or without DNA.

Bacillus subtilis↗
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↗
PubMed1977

[Study of streptococcal L forms in the scanning electron microscope. II. Dynamics of the development of structural elements of L colonies at different stages of growth].

The method of scanning electron microscopy showed that the L-colonies of streptococcus were formed by the spherical structures 0.1--1.5 micronm in diameter, elements of polygonal shape (large bodies) 10--30 micronm in size, filamentous structures 01--7 micronm in diameter and structureless matrix. A regular replacement of one form by another was observed in the process of the L-colonies development. Thus, the spherical elements appeared in the lag-phase, and polygonal elements were found mostly at the initial stages of the L-colonies formation; as to the filamentous structures -- they were present at all the developmental stages, but their diameter increased, and their structure and number changed at different growth phases. The spherical elements of the L-colonies formed evenly both on the structureless depth matrix of the colonies, on the filamentous structures in the form of buds on the "large bodies", and the disintegration of the latter. The role of the filamentous structures in the development of the L-colonies is discussed.

L Forms↗
PubMed1977

[Morphologic characteristics of the large bodies in cultures of the L-forms of bacteria according to scanning electron microscope studies].

Large bodies appear at the time of protoplast and spheroplast formation and are revealed at all the L-transformation stages and at the initial stage of reversion. They can be represented both by a single giant cell and by a conglomerate of different cells connected with one another. They are not only spheroid, but can be of the most varied shape, and structurally they are connected with other L-colony elements: filamentous structures, spheroid cells, elementary bodies and the so-called acellular material. At the early L-transformation stage the large bodies probably appear as a result of coalescence of lysed cells and represent polygenome formations. Elementary bodies and spheroid cells form within the large bodies and on their surface at the late stage of L-transformation. In case of reversion bacterial cells form from them.

L Forms↗
PubMed1977

[Biological properties and ultrastructure of brucellae during L-transformation and reversion].

There was shown a difference in the biological properties and the ultrastructure of two strains of brucellae, spheroplasts obtained from them under the action of penicillin, L-form and revertants obtained from the L-form. Spheroplasts formation was characterized by a change of brucellae into R-form and some virulence reduction. The cells had an outer and a cytoplasmic membranes, and usually lost their capacity to binary division. L-forms were obtained during the 9th and the 35th passage on a medium with penicillin; their formation was accompanied by the change in serological properties of the culture and significant reduction of the virulence; the cells were characterized by a marked polymorphism and the capacity to budding; they had 2 membranes on the cell surface and an intensively developed system of intracytoplasmic membranes. The revertants formed on the medium without penicillin during the 16th-30th passage or spontaneously on the medium with penicillin. They differed from the initial strains of brucella culture by a marked increase in penicillin-resistance, by the changes in serological properties, and also by polymorphism of cells, capable, however, of binary division.

Brucella abortus↗
PubMed1977

[Morphologic characteristics of spheroid elements in a culture of bacterial L-forms according to scanning electron microscopy findings].

The authors studied stable L-cultures of Proteus valgaris, Bac. subtillis, Staphylococcus aureus, Streptococcus pyogenes of group A, and also unstable cultures of the L-forms of Proteus vulgaris and Proteus vulgaris culture at the stage of spheroplasts. Spheroid cells proved to appear at the stage of spheroplasts, prevailed at the log phase in stable and unstable L-cultures, but were less frequent at the stationary phase. Cross section of L-colonies showed that they were located at the surface. The size of spheroid elements was from 1 to 5 micron; their surface was smooth or slightly wrinkled with numerous protrusions and individual sockets. The spheroid cells were distributed in the colonies freely, in clusters, or were connected to one another by anastomosis. Several methods of reproduction of spheroid cells are described, including equal and unequal binary fission, budding, and formation of elementary bodies within the cell. Morphological connection of spheroid cells with large bodies, filamentous structures and structureless matrix of the L-colony apparently pointed to their origin from the corresponding elements of the L-cultures.

Bacillus subtilis↗
PubMed1977

[Certain data on the protoplast ultrastructure].

A study was made of the structure of Bac. subtilis and Listeria monocytogenes protoplasts by the method of scanning electron microscopy. The mechanism of protoplast formation in Gram-positive bacteria and in spheroplasts of Gram-negative bacteria proved to differ. A loss of the rigid form of the cell, round protrusions on cell surface, and an escape of the cytoplasm through the ruptured cell wall in some one place was noted in case of protoplasts. Individual cells can coalesce with one another with the formation of shapeless masses. The formation of small spheroid bodies by budding, and also a division of protoplasts by constriction was described.

Bacillus subtilis↗
PubMed1976

[L-forms of streptococcus in the scanning electron microscope. 1. Structural elements of L-colonies].

Broth culture of stable L-forms of beta-hemolytic streptococcus, group A, was studied in the log phase. Internal portion of the centrifugate constituting the matrix of the L-population represented a structureless mass in which the borders of individual cells were not always distinct; the cells adhered to one another and were irregular in shape. The described morphological picture corresponded to the internal part of the L-colonies from the semifluid medium in observation under phase and scanning microscope. A more peripheral portion of the centrifugate was formed by the spherical cells, about 2 mum in diameter; penetrating holes or crater-like invaginates and also small spherical structures, about 0.5 mum in diameter were often revealed on these cells. Filamentous structures, up to 200 mum in length which protruded far into the surrounding environment served as the most peripheral elements. Analogous structure were described in the L-colonies examined by phase contrast microscopy. The data of transmission and scanning microscopy are compared.

L Forms↗
PubMed1976

[A study of Proteus L forms during reversion by means of electron microscopy and ultrathin sections].

The method of scanning electron microscopy was applied to the study of the Proteus L-forms which reversed directly on the millipore filters. It appeared that reversion was accompanied by elongation of the cell, piriform cells forming as the result. Filamentous cells segmented into short fragments and large bodies with a spongy surface structure with numerous ruptures were also revealed in the reversing culture. The method of ultrathin sections showed the other membrane in many cells to be fragile and readily twisting forming vesicles collecting into chains. As supposed, this is connected with degenerative changes involving the outer membrane of the paternal L-forms at the early reversion periods. An interrupted structure of the outer membrane was also demonstrated in many cells. It is supposed that in this case a synthesis of the outer membrane de novo at the later stages of reversion is dealt with. Phenomenon of "extrusion" of the multilayer structures into the periplasmic space, characteristic of spheroplasts, is described. A marked similarity of the morphological picture of reversion and at the initial stages of L-transformation, i.e. of the processes representing a looking glass reflection of one another, is described.

Cell Membrane↗
PubMed1976

[In vitro obtaining stable L forms of group A beta-hemolytic streptococci type 1 and 12].

Stable L-forms of hemolytic streptococcus of group A of the 1st and 12th types were obtained in vitro under the effect of penicillin. L-form strains were passaged over 40 times and failed to reverse to the initial. Stability of the obtained L-cultures of the 1st and 12th types was confirmed by electron microscopy which showed the absence of cell wall in them. Morphology of the colonies on hard nutrient medium showed some difference in the L-form strains of the 1st and 12th type. Phage contrast microscopy demonstrated in the culture of the 12th type a relatively greater number of granular structures; as to the L-form cultures of the 1st type, it was mainly represented by the globular elements. Submicroscopic characteristic of the L-form of streptococcus was revealed on the ultra-thin sections of both L-form strains.

Culture Media↗