Yersinia pseudotuberculosis-derived adhesins

Around fifteen surface components referred to adhesins have been identified in Yersinia pseudotuberculosis combining primarily microbiological, molecular and genetic, as well as immunochemical and biophysical methods. Y. pseudotuberculosis-derived adhesins vary in structure and chemical composition but they are mainly presented by protein molecules. Some of them were shown to participate not only in adhesive but in other pathogen-related physiological functions in the host-parasite interplay. Adhesins can mediate bacterial adhesion to eukaryotic cell either directly or via the extracellular matrix components. These adhesion molecules are encoded by chromosomal DNA excepting YadA protein which gene is located in the calcium-dependence plasmid pYV common for pathogenic yersisniae. An optimum temperature for adhesin biosynthesis is located close to the body temperature of warm-blooded animals; however, at low temperature only invasin InvA, full-length smooth lipopolysaccharide and porin OmpF are produced in Y. pseudotuberculosis. Several adhesins (Psa, InvA) can be expressed at low pH (corresponds to intracellular content), thereby defining pathogenic yersiniae as facultative intracellular parasites. Three human Yersinia genus pathogens differ by ability to produce adhesins. Y. pseudotuberculosis adherence to host cells or extracellular matrix components is determined by a cumulative adhesion-based activity, which expression depends on chemical composition and physicochemical environmental conditions. It’s proposed that at the initial stage of infectious process adherence of Y. pseudotuberculosis to intestinal epithelium is mediated by InvA protein and “smooth” LPS form. These adhesins are produced in bacterial cells at low (lower than 30°С) temperature occurring in environment from which a pathogen invades into the host. At later stages of pathogenesis, after penetrating through intestinal epithelium, bacterial cells produce other adhesins, which promote survival and dissemination primarily into the mesenteric lymph nodes and, possibly, liver and spleen. At later stages of pathogenesis, after penetrating through intestinal epithelium, bacterial cells produce other adhesins, which promote survival and dissemination primarily into the mesenteric lymph nodes and, perhaps, liver and spleen. Qualitative and quantitative spectrum of Y. pseudotuberculosis adhesins is determined by environmental parameters (intercellular space, intracellular content within the diverse eukaryotic cells)

Effect of Bacteriophages and Gentamycine on Morphology and Vesicle Formation of Bacteria Yersinia pestis EV

Objective was to assess the effect of specific bacteriophages and gentamycine on the morphological-functional properties of bacteria in the vaccine strain Yersinia pestis EV.Materials and methods. The vaccine strain Y. pestis EV, Pokrovskaya bacteriophage and the pseudotuberculous diagnostic bacteriophage were used for the study. The microbial culture was grown on solid and in liquid growth media at 27 °C for 20–24 h. The co-incubation of bacteria and bacteriophage or gentamycine was carried out at 27 °C for 20 minutes or at 37 °C for 2 hours, respectively. Culture preparations were examined by transmission electron microscopy.Results and discussion. The influence of cultivation conditions and various stress factors on the vesicle production by the vaccine strain Y. pestis EV cells was evaluated. The nature and intensity of morphological-functional changes in Y. pestis EV cells in response to the effect of bacteriophages (plague Pokrovskaya and pseudotuberculous bacteriophages) or an antibiotic (gentamycine) were determined. It was established that co-incubation of Y. pestis EV with Pokrovskaya bacteriophage or gentamycine for 20 min leads to the increase in the production of extracellular vesicles and is accompanied by the development of degenerative changes in bacterial cells

Electron-Microscopic Investigation of Interactions between <I>Yersinia pseudotuberculosis</I>, <I>Yersinia pestis</I> Cells and Specific Bacteriophages

Carried out has been electron-microscopic investigation of dynamics of interactions between Yersinia pseudotuberculosis, Yersinia pestis cells and specific bacteriophages in vitro. Identified have been peculiarities in morphological manifestation of the interactions. Determined are morphometric characteristics of the bacteriophages utilized in the experiment. It is demonstrated that after 40 minutes of co-incubation of Y. pseudotuberculosis with specific bacteriophage emergence of persisting forms of microbial cells is observed, while in case of EV strain infecting with Pokrovskaya bacteriophage, this phenomenon is not detected

The Experience of Application of <i>Yersinia pestis</i> Antigens for Plague Chemical Vaccine Development

The review presents data on history and current status of the problem of chemical plague vaccine development Literature data about protective activity of some Yersinia pestis monoantigens as well as immunogenic properties of complex antigen preparations are summarized. The possibility and expediency of development of the appropriate vaccine preparations are evaluated, including their potential role and significance for the specific plague prophylaxis as the anti-epidemic measure

Effects of <i>Yersinia pestis</i> Fra-Operon Carriage on the Cellular Morphologic Features of the Recipient <i>Yersinia pseudotuberculosis</i> Strain

Cellular morphologic variations of Yersinia pseudotuberculosis strain 164/84 were assessed depending on the cultivation temperature and the plague agent's fra-operon carriage by these cells. Notably slower population growth of the two isogenic variants of strain 164/84 (fra+ and fra-) was observed at the cultivation temperatures of 4 to 6 °C as compared with those at 26-28 °C and 36-38 °C. Only late growth stages at the temperatures of 36 to 38 °C brought about significant differences between the fra+ and fra- cell variants expressed in the occurrence of relatively bigger cells in the population of the capsule forming Y. pseudotuberculosis variant

IMMUNOCHEMICAL STUDY OF RECEPTION OF PLAGUE BACTERIOPHAGE POKROVSKY

Aim. Study of mechanism of reception of plague bacteriophage Pokrovsky to cells of Yersinia pestis using a panel of monoclonal antibodies. Materials and methods. Using a method of competitive inhibition, the ability of monoclonal antibodies against antigenic epitopes of outer membrane of Yersinia genus bacteria to inhibit adhesion of the studied bacteriophage to cells of Y. pestis EV strain, was evaluated. Results. A key role of structure of carbohydrate nature in reception of Pokrovsky bacteriophage was confirmed. Among 5 lines of monoclonal antibodies against protein epitopes 2 were established to cause significant inactivation of bacteriophage adhesion to bacterial cells. Conclusion. An assumption is proposed regarding participation of a structure of polypeptide nature in reception of Pokrovsky bacteriophage by cells of plague microbe

Force interactions between Yersiniae lipopolysaccharides and monoclonal antibodies: An optical tweezers study

© 2019 This article reports the force spectroscopy investigation of interactions between lipopolysaccharides (LPSs) of two species from Yersinia genus and complementary (or heterologous) monoclonal antibodies (mAbs). We have obtained the experimental data by optical trapping on the “sensitized polystyrene microsphere – sensitized glass substrate” model system at its approach – retraction in vertical plane. We detected non-specific interactions in low-amplitude areas on histograms mainly due to physicochemical properties of abiotic surface and specific interactions in complementary pairs “antigen – antibodies” in high-amplitude areas (100–120 pN) on histograms. The developed measurement procedure can be used for detection of rupture forces in other molecular pairs

Oxygen-Dependent Recovery of Yersinia pestis Viability

The following technique is offered for restoration of viability of Yersinia pestis cultures lyophilized at -(20±2) °C and stored for a long time (7-16 months): 10 cm3 melted culture in a 120 cm3 glass bottle under cotton stoppers is aerated by rocking in a shaker at (27±1) °C. The process of reparation of the injured bacteria was shown to depend on the presence of the oxygen and energetic sources. Viability reparation was prevented in the atmosphere of argon, when cells' breath was inhibited by cyanide (KCN), and in the case of uncoupling of the oxidative phosphorylation process by 2,4-dinitriphenol (2,4-DNF). Reparation capability was manifested by the bacterial cultures that had retained energy-dependent autoregulation of the breathing activity, estimated according to the respiration parameters, and especially by the magnitude of the metabolic breathing control (MBC)

\u3cem\u3e Yersinia\u3c/em\u3e Outer Membrane Vesicles as Potential Vaccine Candidates in Protecting Against Plague

Despite the relatively low incidence of plague, its etiological agent, Yersinia pestis, is an exceptional epidemic danger due to the high infectivity and mortality of this infectious disease. Reports on the isolation of drug-resistant Y. pestis strains indicate the advisability of using asymmetric responses, such as phage therapy and vaccine prophylaxis in the fight against this problem. The current relatively effective live plague vaccine is not approved for use in most countries because of its ability to cause heavy local and system reactions and even a generalized infectious process in people with a repressed immune status or metabolic disorders, as well as lethal infection in some species of nonhuman primates. Therefore, developing alternative vaccines is of high priority and importance. However, until now, work on the development of plague vaccines has mainly focused on screening for the potential immunogens. Several investigators have identified the protective potency of bacterial outer membrane vesicles (OMVs) as a promising basis for bacterial vaccine candidates. This review is aimed at presenting these candidates of plague vaccine and the results of their analysis in animal models