RESUMO
AIM: Studies of influence of Yersinia pestis fra-operon carriage on morphological properties of Y. pseudotuberculosis recipient strain cells and colonies at different temperature and cultivation time. MATERIALS AND METHODS: Cultures of Y. pseudotuberculosis isogenic variants were grown on solid nutrient medium at 4 - 6, 9 - 11, 26 - 28 and 36 - 38 degrees C. Indirect hemagglutination was used to determine F1 antigen production. Cytorefractometry was used to determine live cell percentage in colonies. Size and dividing cells percentage was evaluated by using phase-contrast microscope "Lyumam-I2". RESULTS: Time period between appearance of micro-colonies and achievement of maximum colony size increased with cultivation temperature decrease. Size of fra+ and fra- variant colony was not significantly different for every temperature regiment used and was significantly lower at the temperature of 36 - 38 degrees C. CONCLUSION: Temperature has a significant influence on population growth, colony size and form.
Assuntos
Proteínas de Bactérias/análise , Yersinia pseudotuberculosis , Contagem de Colônia Microbiana , Testes de Hemaglutinação , Viabilidade Microbiana , Óperon/genética , Plasmídeos , Temperatura , Transformação Genética , Yersinia pestis/genética , Yersinia pestis/crescimento & desenvolvimento , Yersinia pseudotuberculosis/genética , Yersinia pseudotuberculosis/crescimento & desenvolvimentoRESUMO
The biological and physico-chemical properties of cultures of two isogenous recombinant variants of Yersinia pseudotuberculosis were studied. The cell genomes of the cultures are distinguished from one another only by the presence or by the absence of the fra-operon, which is a determined attribute of the plague microbe capsule-forming process. The expression of the attribute is amplified by rising the microbial biomass cultivation temperature and stimulates the decrease in the viability of the bacteria and adaptation potential in vitro. In the warm-blooded owner organism the microbes of the capsule-forming recombinant variant are characterized by the greater residual pathogenicity and immunogenic ability to the experimental plague of the laboratory animals as compared to the reference-variant cells. These specific features could be explained by more expressed colonizing ability of the capsule-forming microbes provided by owner cells' stability to the phagocyte process.
Assuntos
Cápsulas Bacterianas/genética , Genoma Bacteriano/genética , Óperon/genética , Yersinia pestis/genética , Yersinia pseudotuberculosis/genética , Cápsulas Bacterianas/imunologia , Contagem de Colônia Microbiana , Genoma Bacteriano/imunologia , Óperon/imunologia , Yersinia pestis/imunologia , Yersinia pseudotuberculosis/crescimento & desenvolvimento , Yersinia pseudotuberculosis/imunologiaRESUMO
The results of the evaluation of the immunogenic properties of B-antigen, earlier identified in the culture fluid of Yersinia pseudotuberculosis submerged culture, with respect to experimental plague and pseudotuberculosis are presented. B-antigen has been shown to produce protective effect in guinea pigs and, probably, hamadryas baboons, but not in white mice infected with the causative agent of plague. Immunizaton with B-antigen protects guinea pigs from primary pneumonic plague caused by both capsule-forming and noncapsular Y. pestis virulent strains. Passive immunization with antibodies to B-antigen induces limitedly pronounced protective effect in guinea pigs and is not effective for white mice with respect to experimental plague. No active or passive protection of white mice or guinea pigs, infected with Y. pseudotuberculosis cultures, has been achieved by the injection of B-antigen or antibodies to it.
Assuntos
Proteínas de Bactérias/administração & dosagem , Imunização Passiva , Vacina contra a Peste/administração & dosagem , Peste/prevenção & controle , Superantígenos/administração & dosagem , Vacinação , Infecções por Yersinia pseudotuberculosis/prevenção & controle , Yersinia pseudotuberculosis , Animais , Anticorpos Antibacterianos/administração & dosagem , Proteínas de Bactérias/imunologia , Esquema de Medicação , Avaliação Pré-Clínica de Medicamentos , Cobaias , Imunoglobulina G/administração & dosagem , Injeções Intraperitoneais , Injeções Subcutâneas , Camundongos , Papio hamadryas , Peste/terapia , Vacina contra a Peste/imunologia , Coelhos , Superantígenos/imunologia , Yersinia pseudotuberculosis/imunologia , Infecções por Yersinia pseudotuberculosis/terapiaRESUMO
Effect of inoculation with canine distemper virus (CDV) strains of various virulence or vaccination with commercial polyvalent preparations on the immune status of puppies has been studied. Serum interferon concentration did not change, irrespective of the strain appurtenance of CDV, while the concentration of tumor necrosis factor-alpha decreased on days 4-14 after the virus inoculation. According to the lymphocyte stimulation test (LST), virulent strain Snyder Hill and reactogenic variant U were characterized by a pronounced immunosuppressive effect. Vaccine strain VNiiViM-88 exerted a stimulating effect in LST. Vanguard 5/L vaccine suppressed the immunity for up to 2 weeks. Vacchum, VNiiViM, and experimental vaccine manufactured by a joint-stock company Vetzverotsentr+ activated the mitogen-induced lymphocyte blastogenesis.
