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Biomedical subjects

G S Dunaev

Publications and source records attributed to G S Dunaev.

14 recordsLinked to original sources

[Yersinia pestis L-forms in rodents and ectoparasites].

Y. pestis L-forms and bacterial forms persist in the body of great gerbils for 40 days. L-forms are poorly phagocytized and can persist in phagocytes for a long time. In guinea pigs immunized with vaccine EV, Y. pestis antigen could be detected till day 160. An unstable L-form was isolated from Ornithodoros mites 3 years after their experimental infection with Y. pestis. Bacterial forms persist in mites for 1-3 years. For 5 years Y. pestis antigen is regularly detected in a high percentage of mites.

Animals↗

[Isolation of L-form of Yersinia pestis from wild rodents in an epizootic focus].

Four Y. pestis cultures with unbalanced growth and 15 Y. pestis cultures in unstable L-forms were isolated from wild rodents Rhombomys opimus in the vicinity of lake Balkhash. Morphologically they were mainly represented by granular, spheroplast-like and filiform elements. When stained with luminescent serum, they acquired specific fluorescence; in indirect hemagglutination they yielded positive result. Electron microscopy revealed the presence of morphological elements characteristic of the process of L-transformation. After subculturing reversion to rod-like forms was observed in 13 Y. pestis strains.

Animals↗

[Production of L forms of the plague microbe].

Experiments were conducted in vitro. The process of formation of unstable L-form cultures of Pasteurella pestis under the effect of penicillin was studied. A comparatively high frequency of this phenomenon in various strains was demonstrated. A possible role of the L-transformation process in the persistence of the causative agent in the organism of wild animals in endemic foci of infection is put forward.

Culture Media↗

[Pathogenicity of nonagglutinating vibrios].

In studying the pathogenicity of nonagglutinating vibrios it was established that the majority of the strains isolated from the patients suffering from enteritis possessed enteropathogenic properties which were revealed in the trials on nursling rabbits and on the isolated intestinal loop a of an adult rabbit. In difference to the cholera vibryos, these microorganisms produced no typical cholerogenicity syndrome expressing, however, a number of enteropathogenic properties: caused diarrhea, overfilling of the intestine with fluid, etc. Autopsy showed a typical enterocolitis picture, confirmed by histological studies. Nonagglutinating vibrio cultures isolated from the water and from healthy persons possessed no enteropathogenic properties. An isolated intestinal loop of an adult rabbit proved to be the most sensitive experimental model.

Animals↗

[Specific immune complexes and neutrophil injury test in the diagnosis of experimental glanders and melioidosis].

The authors have demonstrated the possibility of using solid-phase enzyme immunoassay to detect specific circulating immune complexes without their preliminary separation in guinea pigs infected with Pseudomonas mallei and Pseudomonas pseudomallei. They have examined the prospects of using neutrophil injury test and solid-phase enzyme immunoassay for the detection of specific immune complexes as additional tests used to predict the outcome of an infectious process in glanders and melioidosis.

Animals↗