[Property of collection strains and new isolates of Shigella sonnei].

The vital ability, serological properties, antibioticograms and biochemical properties of collection strains and new isolates of Shigella sonnei have been studied. It was ascertained that the determined factors are sufficiently variable, thus they cannot be used as the independent basis for the classification of pathogens.

[Change of serological properties of museum strains of Shigella flexneri in different terms of storage].

The viability, purity, biological and serological properties of museum strains of Shigella flexneri which were kept in lyophilized state during above 30 years were studied. Primary serological characteristics were specified, it was established that type 2a is the predominant serotype independent of the years and regions of isolation. Some strains lost antigens as a result of the long-term preservation or reinoculation on agar media.

[The pathogenetic aspects of the hyaluronidase activity of Proteus mirabilis].

The hyaluronidase activity of 83 P. mirabilis strains has been studied. The strains isolated from patients with chronic urologic infection possess the highest hyaluronidase activity, while the activity of strains isolated in cases of enteric disturbances and from purulent wound exudate has proved to be considerably lower, the difference between the latter being statistically insignificant.

[The mechanisms of Proteus mirabilis resistance to the bactericidal action of blood serum].

When studying sensitivity of Proteus mirabilis to bactericide effect of blood serum the resistance to alternative way of the complement activation was found in a number of strains. The population of cells with morphologically determinable changes of the surface structures resistant to bactericide effect of the serum is formed as affected by the blood serum of the culture P. mirabilis.

[The antibacterial immunity of people under dynamic observation in an altered radiation situation].

The comparative study of the isolation rate, level, antigenic and class specificity of serum antibodies to the causative agents of purulent septic infections (Staphylococcus aureus, Pseudomonas aeruginosa, Proteus mirabilis) and acute enteric infections in healthy adults with different ABO blood groups before (836 persons) and after (1,429 persons) the catastrophe at the Chernobyl nuclear power station was made. The study revealed the fact that the genesis of antibodies directed against different microorganisms can be stimulated without additional antigenic challenge in the form of disease or immunization, which was definitely indicative of the influence of small radiation doses in Kiev on the humoral immunity of the population. The multifactor character of the dependence of antibacterial antibody formation under altered radiation conditions on the specific features of the infective agent and the intensity of its circulation among the population, individual immune responsiveness of the body and concrete radiation conditions was established.