Yersinia pestis Surface Antigens in Reception of Specific Bacteriophages.

The significance of Yersinia pestis surface antigens in adhesiveness to specific bacteriophages has been studied with the use of two methodological approaches. It was shown that Ail protein immobilized on the surface of polystyrene microspheres (but not in the solution), can bind both the Pokrovskaya phage and pseudotuberculous diagnostic phage. YapF autotransporter interacted with both phages in a water-soluble form, but YapF bound to polystyrene microspheres interacted only with the Pokrovskaya phage. An assumption was made that Ail and YapF proteins can be the primary receptors providing non-specific reversible binding to the phages used in this work.

Influence of Specific Bacteriophage on the Level of Vesicle Formation and Morphology of Cells of Yersinia pseudotuberculosis.

Incubation of Yersinia pseudotuberculosis cells grown on a solid medium with pseudotuberculous diagnostic bacteriophage for 20 min at 37oC led to a significant decrease in the concentration of both components of the system. This effect was absent when the bacteria were grown in a fluid medium. At the same time, this incubation regimen promoted vesicle formation and typical morphological changes in bacteria grown in both surface and suspension cultures. Co-incubation of the bacteriophage with suspension of vesicles isolated from the suspension culture of Y. pseudotuberculosis grown at 10oC (but not 37oC) led to a decrease in plaque-forming activity of the bacteriophage.

Immunochemical Nature of Receptors of Pseudotuberculosis Diagnostic Bacteriophage.

The effect of treatment of Yersinia pseudotuberculosis cells with antibodies of various specificities on adhesiveness of pseudotuberculosis bacteriophage was analyzed by competitive inhibition technique. Bacteriophage adsorption to bacteria was sterically inhibited by monoclonal antibodies to protein epitopes of Y. pseudotuberculosis outer membrane. These results suggest that receptors of pseudotuberculosis diagnostic bacteriophage are localized on the LPS core of microbial cell.

[IMMUNOCHEMICAL ACTIVITY OF YERSINIA PSEUDOTUBERCULOSIS B-ANTIGEN].

A hybridoma panel producing monoclonal antibodies to immunochemically non-identical antigenic epitopes of the protein nature located in outer membrane of Yersinia pseudotuberculosis was obtained. It was revealed that the previously identified B-antigen protecting laboratory animals from experimental plague was detected using both monoclonal antibodies against mentioned protein determinants and the determinants of lipopolysaccharide O-side chains. The B-antigen is a component of the Y. pseudotuberculosis outer membrane, egested in the form of the vesicles (OMVs) by bacteria cultivated in fluid nutrient medium.

[Study of Yersinia pseudotuberculosis surface antigen epitopes using monoclonal antibodies].

A study of the influence of exogenous factors on the immunochemical activity of the bacterium Yersinia pseudotuberculosis and lipopolysaccharide preparations isolated from bacteria was performed using monoclonal antibodies. It was shown that the hybridomas that were obtained in this work produce antibodies against different and, most likely, species-specific epitopes associated with lipopolysaccharide O side chains. The antibody concentrations produced increased with a decrease in the temperature, at which the bacteria were cultivated. An inhibitory effect of proteinase K, pepsin, and trypsin on the immunochemical activity of bacterial cells, determined using a solid-phase enzyme immunoassay, was demonstrated. Treatment with sodium periodate showed no uniform effect on the reactions between monoclonal antibodies and antigens (lipopolysaccharides and microbial cells), as adjudged by an immunoassay, which is most likely a consequence of the different localization of lipopolysaccharide epitopes recognized by the antibodies from four hybridomas.