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S A Gulevskaia

Publications and source records attributed to S A Gulevskaia.

At least 19 recordsLinked to original sources
PubMed1984

[Yield of Chlamydia from an infected cell studied by scanning electron microscopy].

The study of the monolayer cell culture L-929, infected with strain CP-1 isolated from a patient with Reiter's syndrome, by means of scanning electron microscopy demonstrated that the release of chlamydiae from infected cells occurred in two ways: (1) by active ejection, probably as the consequence of the local rupture of the host cell, and (2) by more quiet "eruption" due to rupture in the plasmolemma . Elementary chlamydial bodies released from the cell had a spherical form, and reticular bodies had an irregularly spherical form, often with recesses and digitiform protrusions.

Animals↗
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

[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↗
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↗
PubMed1975

[Current data on the polymorphism of Rickettsia prowazekii and burneti in cultured cells].

In cultivation of Rickettsia prowazeki (strains Breinl and E) in the cell cultures of guinea pig kidneys (GPK) and chick embryo fibroblasts (CEF) ultrastructure of rickettsia of unusual shape (filamentous, irregularpleomorphic and spheroplast-like) were revealed along with rickettsia of the usual shape and size. The polymorphism was less pronounced in the GPK and the CEF cells of Rickettsia burneti (strain M-44). It is supposed that rickettsial polymorphism was not associated with their developmental cycle and served as a morphological expression of the changes in the microorganism under the effect of unfavourable ecological conditions. The appearance of filamentous forms could be associated with disturbed cell division process; changed rigidity of the cell wall could serve as the cause of appearance of pleomorphic rickettsia. In difference from polymorphism, the cycle of rickettsial development is considered to be (in the basis of modern electron microscopic data) as a biological replacement of the vegetative (rod-like, bacillary) forms by those more stable in the external environment, resting (coccoid).

Animals↗
PubMedDate not supplied

[The 1(2)-dehydrogenation of steroid substrates by Nocardioides simplex VKM Ac-2033D].

The bacterium formerly known as Arthrobacter globiformis 193 has high 1(2)-dehydrogenase activity toward pharmaceutically important steroids, 9(11)-dehydrocortexolone in particular. The complex analysis of the morphostructural, physiological, biochemical, and phylogenetic properties of this bacterium allowed us to reclassify it into Nocardioides simplex (N. simplex VKM Ac-2033D).

Arthrobacter↗