[Immunogenicity of Yersinia pestis grown on nutrient media at 28 and 37 degrees C].

The immunogenicity of Y. pestis strain EV, grown in yeast-casein medium, yeast medium with Hottinger digest and yeast medium with sunflower-seed protein at 28 degrees C and 37 degrees C, for guinea pigs and white mice has been studied. As revealed in this study, these media ensure the formation of highly immunogenic populations of Y.

[Virulence, viability and antibiotic sensitivity of the causative agent of plague growing on nutrient media at 28 and 37 degrees C].

A comparative study of virulence, viability and antibiotic sensitivity of Y. pestis strains grown at 28 degrees C and 37 degrees C in yeast-casein medium, yeast medium with Hottinger's meat digest and yeast medium with protein hydrolysate obtained from sunflower seed groats has been made. These media have been found to be suitable for the prolonged cultivation of Y.

[Determination of groups at risk for acute intestinal infections by a population questionnaire].

Questionnaires were distributed in 3308 families divided into two groups: group 1 with no cases of acute intestinal infections and group 2 where such cases were registered. Information contained in the questionnaires was processes by means of computers bzsm-6. The analysis of the data on the occurrence of characteristics indicating the quality of water supply and water consumption (25 characteristics), sewage and sanitation (12 characteristics), living conditions (19 characteristics) showed that the living conditions of the families in group 2 were worse than those of the families in group 1.

[NAG-vibrio serovar 2 causing a generalized infection].

A case of septicemia caused by NAG-vibrio, serovar 2, is described. In contrast to other vibrios, the strain under study was immobile at the moment of isolation and, when introduced enterally into suckling rabbits, showed the capacity of causing generalized infection.

[Electron microscopic study of the structural organization of cholera phage C].

Electron microscopy methods were used to determine the main parameters of the structural organization of cholera "C" phage. The particles of the phage were found to consist of a capsid of icosahedral shape and a thin noncontractile process. The capsid with the triangulation number 7 consists of 72 morphological subunits and contains DNA with the molecular weight of (68.

[Lysogenic conversion of cholera vibrios].

As a result of ultraviolet irradiation and treatment with nitrosmethyl urea, mitomycin C, ascorbic acid and sarcolysin, the elimination of prophage from wild lysogenic Vibrio cholerae strains, biotype El Tor, has been achieved. The elimination of prophage was accompanied by a change in the biological properties of the vibrios, and some of these biological properties were found to be correlated with the lysogenization of Vibrio cholerae by the definite races of temperate phages. Only a few races of type II phages, whose genome was responsible for the serological characteristics of the strain, its sensitivity to cholera diagnostic phages and polymyxin, were capable of conversion.

[Preservation of cholerogenicity in cholera vibrios in the incomplete L-cycle stage].

The work presents the characteristics of the forms appearing as a result of the incomplete L cycle of Vibrio cholerae obtained in experimental conditions after the cultivation of typical V. eltor strain, serovar Ogawa, for 5 months at room temperature in sterile river water without subculturing. The culture formed shaprly changed L-similar colonies, had decreased agglutinability and was resistant to diagnostic cholera phages, but retained its cholerogenicity for suckling rabbits.

[Ultrastructure of the L forms of cholera and NAG vibrios].

Ultrastructure of L-forms of cholera and NAG-vibrios obtained under the effect of penicillin, tetracycline, in prolonged cultivations, and isolated from the external environment was studied. There proved to be no principal differences in their ultrastructural organization. Cells of sphero- and protoplastic type were distinguished in the colonies.

[Detection of L forms of Vibrio cholerae in the water of open water reservoirs].

L-forms of cholera vibrios were isolated from the river water for the first time. The presence of L-forms in water permitted to suppose that such variants served as one of the forms of cholera causative agent preservation in the external medium.

[Electron microscopic study of the structure of cholera bacteriophage serotype II].

The methods of electron microscopy and optic difraction were used to determine the main parameters of the structural organization of cholera bacteriophage of serotype II. The virions of the phage under study were found to consist of a capsid of icosahedral shape and 77.4 X 66.

[Electron microscopy of cholera vibrios from the intestinal contents of infected suckling rabbits].

Electron microscopic study of the cells of classic, El Tor and NAG-vibrios showed them to be no different by the structure type from the cells of ofter Gram-negative bacteria. A characteristic peculiarity of the cholera vibrios revealed after their passage through the intestine of nursling rabbits was the presence of microcapsules and protrusions of the areas of the wall membranous apparatus.