[The problems of identification of various strains of vegetative form of Bacillus anthracis using MALDI-ToF MS technique.]

The article considers experience of application of mass-spectrometry with matrix-activated laser desorption/ionization for fast and reliable identification of Bacillus anthracis and heterologous species of microorganisms. The particular interesting characteristics and difficulties occurred during identification are covered.

[The diagnostic significance of particular immune-dominating proteins of isogenic variants of Bacillus Anthracis.]

The polyclonal mono-specific sera to proteins of toxin and antigens of S-layer of Bacillus Anthracis separated in preparative electrophoresis. While fluorescent antibody technique was applied, immunoglobulins of sera to protein of S-layer of Bacillus Anthracis m.m. 94 kDa had specificity and specific activity in presented number of strains. In the soil samples spores in concentration of 1x104 KOE/ml were detected that permits to recommend the given immunoglobulins for indexation of Bacillus Anthracis. The proteins m.m. 90 kDa relevant to antigens of toxin of Bacillus Anthracis reacted in immuno-blotting with sera from patients with skin form of anthrax and guinea pigs immunized and survived after infection. Thew sera to them are species specified and can be applied for diagnostic of disease (detection of protective antigen) and detection of production of proteins in reaction of immunodiffusion with growing cultures.

[Characteristics of isogenic variants of Bacillus anthracis with various content of virulence plasmids].

AIM: Production and characteristics by main cultural-morphologic and antigenic properties of isogenic variants Bacillus anthracis, that differ by the presence of virulence plasmids. MATERIALS AND METHODS: B. anthracis 81/1, 575/122 virulent and B. anthracis STI, 55, Sterne vaccine strains were used in the study. Isogenic variants, that differ by the presence of virulence plasmids, were obtained by temperature elimination of plasmids, as well as during cultivation of anthrax strains in medium with kanamycin. The strains were characterized by cultural-morphologic, biochemical properties. The presence of virulence plasmids was determined by polymerase chain reaction method. Antigenic properties were studied in immune diffusion reaction with growing cultures with sera against protective antigen and S-layer proteins, electrophoresis, immune blotting. RESULTS: Isogenic variants were produced from virulent strains B. anthracis 81/1, 575/122 and vaccine strains STI, 55, Sterne: mono-plasmid toxin-producing (81/1 R01, 575/122 R01) and capsule-containing (81/1 R02, 575/122 R02), and plasmid-less (81/1 R00, 575/122 R00, STI R00, 55 R00, Sterne R00), that differ by the presence of virulence plasmids. Strains had typical cultural-morphologic properties, differed by biochemical and antigenic properties. Cultural filtrates of toxin-producing strains had protein of anthrax toxin; plasmid-less strains--had proteins, that had molecular masses corresponding to molecular masses of S-layer EA1 and Sap proteins. CONCLUSION: These strains may be used to study variability and proteomic analysis of anthrax causative agent, as well as for isolation of antigens with the aim of evaluating their immune diagnostic significance.

[The optimization of algorithm of laboratory diagnostic of Western Nile fever in territory of Russia].

The article deals with results of study of antigenic chiasms between viruses of Western Nile fever and tick-borne encephalitis using binding immunoassay applied to blood serum from patients residing in various regions of Russia. It is established that to get accurate laboratory diagnostic it is reasonable to apply the proposed algorithm of analysis in which alongside with binding immunoassay such differential criterion as positivity rate is to be implemented to speed up and simplify laboratory diagnostic of infections brought on by viruses of Western Nile fever and tick-borne encephalitis.

[Species-specific sera against surface antigens of Bacillus anthracis strains].

The species-related specificity of sera against 94-KD proteins isolated from culture filtrates of B. anthracis strains with different levels of virulence plasmids was studied to determine whether they might be used to identify the pathogen of anthrax. Sera against fractions 1 of culture filtrates of B. anthracis strains CTI (pXO1+ pXO2-), 81/1TR (pXO1- pXO2-), Davies (pXO1- pXO) separated by gel chromatography on Sephacryl S-300 were examined. In the gel immunodiffusion test with growing cultures, the sera exhibited non-identical antigens and differed in the presence of antibodies to antigens of related bacilli. The sera against fractions 1 of culture filtrates of toxin-producing and plasmidless strains displayed antigens produced only by B. anthracis strains into nutrient agar. Electroimmunotransblotting revealed that they contained antibodies mainly to 94-kD proteins and failed to react with B. cereus proteins with a molecular weight of 94 kD and with B. thuringiensis proteins with a molecular weight of 97 kD, which were extracted from autonomous cells. In the immunofluorescence test, immunoglobulins of sera against fractions 1 of culture filtrates of three strains stained autonomous cells and spores of 23 B. anthracis strains with different levels of virulence plasmids. In working dilutions, they did not react with antigens of 18 strains of related bacilli, which presents a possibility of using them for species identification of B. anthracis.