[The choice of the method for determining the potential pathogenicity of shigellae].

The biological characteristics of 196 Shigella strains, isolated in regions with different levels of the geomagnetic field tension, were under study. Strains able to adsorb Congo red, characterized by antilysozyme activity, hydrophobic, resistant to gentamycin, monomycin, kanamycin, rifampicin were more frequently isolated in the regions with a higher tension of the field, this being confirmed by a stable correlation. The ability of Shigellae to fix Congo red correlated with the before signs and with colicinogenicity, therefore this test may be recommended for the assessment of Shigella virulence.

[Changes in the clonal structure of staphylococcal populations in a kidney infection model in mice].

The intraperitoneal infection of mice with previously titered doses of staphylococci has been found to regularly induce the formation of the foci of inflammation in the kidneys of mice, from which staphylococcal cultures has been obtained by the inoculation of the kidney material for 8 days (the term of observation). The use of this model has made it possible to carry out the dynamic study of structural changes in the populations of staphylococci by studying the biological properties of 100 subcultures isolated from the kidneys of the infected animals dissected every 24 hours. A decrease in the heterogeneity of the initial population, occurring due to a drop in the number of clones with hemolytic activity, lecithinase activity and smooth variants, has been registered.

[Effect of terrilytin on the activity of nonspecific resistance factors during immunization with staphylococcal anatoxin and staphylococcal infection].

Terrilytin and immobilized terrilytin enhance the activity and intensity of phagocytosis and increase the concentration of lysozyme in nonimmunized animals. Both preparations increase the production of antibodies to staphylococcal alpha-hemolysin, the titers of beta-lysins, the activity and intensity of the phagocytosis of bacterial cells by peripheral blood leukocytes in animals immunized with staphylococcal toxoid and challenged with live staphylococcal culture. In healthy animals terrilytin and immobilized terrilytin induce an increase in total proteolytic activity and in the activity of alpha-1-antitrypsin and alpha-2-macroglobulin, decreased as the result of staphylococcal infection.

[Structural characteristics of staphylococcal populations with various immunobiological exposures in an experiment].

Staphylococcal populations isolated from patients have been found to be heterogeneous with respect to their medicinal resistance and biological properties. Due to the action of the protective factors of the body, a decrease in the number of clones resistant to tetracycline and erythromycin and, after immunobiological procedures (specific immunization, levamisole), also in the number of clones having hemolytic and DNAase activity occurs among staphylococcal populations isolated from the kidneys of infected animals.