[Study of the sensitivity of the L-forms of group A Streptococcus to antibiotics in artificial nutrient media and in human cell cultures]. / Izuchenie chuvstvite'lnosti k antibiotikam L-form streptokokka gruppy A v iskusstvennoi pitate'lnoi srede i v ku'lturakh kletok cheloveka.

Sensitivity of L-forms of group A streptococci to 5 antibiotics such as erythromycin, lincomycin, tetracycline, gentamicin and chloramphenicol was studied in an artificial nutrient medium and cell cultures i.e. human fibroblast diploid cells and transplantable human heart cells (Girardi). In vitro investigation of the antibiotic effect on the streptococcal L-forms revealed their sensitivity to erythromycin (MIC, 0.4 micrograms/ml), lincomycin (MIC, 0.08 microgram/ml) and tetracycline (MIC, 2 micrograms/ml). The streptococcal L-forms were slightly sensitive to gentamicin (MIC, 6 micrograms/ml) and chloramphenicol (MIC, 30 micrograms/ml). Complete inhibition of the growth of the L-forms in the Girardi cells on the 1st day of the experiment after the antibiotics administration in single doses was induced by lincomycin, 5 micrograms/ml, erythromycin, 10 micrograms/ml, and tetracycline, 100 micrograms/ml. In the diploid cells, the respective figures were 50, 100 and 200 micrograms/ml. Chloramphenicol and gentamicin had an inhibitory effect on the growth of the L-forms but produced no sanative effect.

[Effect of intraperitoneal administration of Streptococcus group A and its cell fractions on the development of adjuvant arthritis in rats]. / Vliianie vnutribriushinnogo vvedeniia streptokokka gruppy A i ego kletochnykh fraktsii na razvitie ad''iuvantnogo artrita u krys.

The effect produced by the intraperitoneal injection of live and heat-killed group A streptococci, the fractions of their cell walls (both intact and sonicated) and cytoplasm was studied on 450 white rats with experimental adjuvant arthritis (AA). The injection of live streptococci into rats with AA decreased the swelling of joints (by 70-80% in the second half of the experiment), reduced the titers of rheumatoid-like factor (RLF), and inhibited the development of polyarthritis. The use of heat-killed streptococci gave a less pronounced antiarthritic effect, while the fraction of streptococcal cell walls, similarly to live streptococci, decreased the swelling of joints (by 27-64%); at the same time a considerable drop in the titers of RLF was observed in 3 experiments, and the development of polyarthritis was registered in 38% of the test animals and in 62% of the control animals. In rats with AA the cytoplasm not subjected to ultracentrifugal purification decreased the swelling of joints (by 21-50%) and the titers of RLF. In this case the development of polyarthritis was observed in 48% of the test animals and in 70% of the control animals.

[Determination of the cytotoxic action of cell fractions of Streptococcus group A on continuous human heart cells]. / Opredelenie tsitotoksicheskogo deistviia kletochnykh fraktsii streptokokka gruppy A na perevivaemye kletki serdtsa cheloveka.

The work deals with the study of the cytotoxic action of the fractions of group A streptococcal cells, type 1, on human heart cells in continuous cell cultures, carried out by the method of J. L. Middlebrook and R. B. Dorland based on the determination of the protein content in the surviving monolayer cells. The addition of crude cytoplasm and the supernatant of sonicated streptococcal cell walls to human heart cell culture has made it possible to obtain a statistically significant decrease in the protein content of the remaining monolayer cells. The action of purified cytoplasm has resulted in faint statistically insignificant suppression of cell growth, thus decreasing the content of cell protein. This method of studying the cytotoxicity of streptococcal cell fractions is simple, convenient and can be used in research work.

[Erythrocyte and lymphocyte interaction with streptococcal L-forms]. / Vzaimodeistvie éritrotsitov i limfotsitov s L-formami streptokokka.

The adsorption of human, sheep and human red blood cells and human lymphocytes on the colonies of streptococci in the L-form has been studied. Th electron-microscopic study of the interaction between human lymphocytes and streptococcal L-forms is suspensions has also been carried out. The red blood cells of all species under study, as well as human lymphocytes, have been found capable of being adsorbed on the colonies of streptococci in the L-form, this adsorption occurring only on the periphery of the colony. The study of electron-microscopic preparations has revealed that streptococcal L-forms adhere to the surface (on 1 or 2 sites) and to the processes of human lymphocytes.

[Interaction of streptococcal L-forms and tissue culture cells]. / Vzaimodeistvie L-form streptokokkov i kletok kul'tur tkanei.

The interaction between 2 strains of group A streptococci in L-forms and the cells of the continuous cell lines HEp, HeLa, L, GPK and PEK, as well as the cells of primary human and chick embryo cell cultures was studied under conditions of infection with different doses. In most of the cell cultures used in this study L-form of streptococci showed no pronounced cytopathic effect. They could be isolated, when using cell cultures as inoculum, from the cultivated cells of continuous cell lines during the whole period of the cultivation of the infected monolayer (6--7 days), primary human embryo cell culture up to days 8--11 and from chick embryo cell culture up to days 1--3. In the cells of the continuous cell lines the maximum amount of L-forms was revealed on days 2--3 by the immunofluorescent technique. The ultrathin sections of HEp and HeLa cells infected with L-forms of streptococci were found to contain small elements similar to L-forms inside the cells and on their surface, which was not detected in the infected primary cell cultures.

[Intracytoplasmic membrane structures in the L forms of the hemolytic streptococcus]. / Vnutritsitoplazmaticheskie membrannye struktury u L-form gemoliticheskogo streptokokka.

In studying the submicroscopic structure of the L-form of streptococcus, group A, isolated from the heart tissue of rabbit there were revealed intracytoplasmic membrane structures. Ring lamellar structures were most frequently revealed in the spheroid cells with dense and loose cytoplasm. They were also found in dense cytoplasm of elementary bodies. Myelin-like structures or those resembling a bundle of microtubules were less incident. Fibrillar structures collected into bands, 64--140 nm in with, and located on one or both sides of the cells beside the cytoplasmic membrane were revealed in the spheroid cells. Individual fibrillae, 8 to 10 nm in diameter, adhered one to another, interlaced, and were sometimes located in parallel. The fibrillar band was loose in the lysed cells.

[Submicroscopic structure of the streptococcal L forms isolated from a living body]. / Submikroskopicheskaia struktura L-form streptokokka, vydelennykh iz zhivogo organizma.

The authors studied in the L-forms of streptococcus induced in the living organism. Submicroscopic structure of the L-forms under study was analogous to the L-forms of the museum streptococcus strain and to the L-forms of some other bacteria. As revealed on the ultra-thin sections of the protoplast-like cells the intracytoplasmic membrane structures were located close to the cytoplasmic membrane and also passed through the whole cell in the form of a band. The latter was in contact with the nucleotide. The elemental bodies were found in the vesicular and the protoplastic cells, and also in the space between the cells; sometimes they formed groups surrounded by a membrane.