Studies on aerosol Yersinia pseudotuberculosis infection of guinea-pigs.

Aerosol Y. pseudotuberculosis infection in guinea-pigs has been reproduced. In the course of infectious process, alveolar macrophages respiration is activated due to a rise in their cytochrome oxidase activity.

Virulence and susceptibility to phagocytosis of Pseudomonas pseudomallei R- and S-forms for ground squirrels (Citellus citellus L.).

Virulence and susceptibility to phagocytosis of Pseudomonas pseudomallei R- and S-forms for ground squirrels were studied. The alveolar macrophages and blood leucocytes (polymorphonuclear and mononuclear) was used. S-forms survived and multiplied intracellularly more actively in alveolar macrophages than R-forms and their virulence was considerably higher.

[The invasive properties of Escherichia coli O18 in relation to cell cultures and infections in inbred mice].

Comparative analyses have been carried out on the dynamics of invasion of cell cultures from epithelioid (MK and HE-p-2) and fibroblast (mice fibroblasts) types with strain Escherichia coli 0 18 isolated and characterized earlier, as well as on the invasion of the viscera of inbred mice (BDF1) after subcutaneous (foot pad lesion test) and intravenous inoculation with the same strain. It was established that the realization of the invasion potential of E. coli 018 depends on the cell culture used: cell cultures of epithelioid type are much more sensitive.

[The in vitro multiplication kinetics of Yersinia pseudotuberculosis--the effect of rhamnose, raffinose and sodium succinate].

The reproductive potentials of strains Yersinia pseudotuberculosis serovars I, II, III, IV and V cultivated at different temperatures on media containing rhamnose, raffinose and sodium succinate were examined comparatively. It was established that the growth of serovars I, II and III was activated by sodium succinate at temperatures 4 degrees and 25 degrees C, while serovars IV and V showed lower growth rate regardless of the substrate used. At 37 degrees C D-raffinose activated the growth of the cells of serovars IV and V.

[Yersinia enterocolitica--its multiplication on nutrient media containing rhamnose, raffinose and sodium succinate].

The kinetics of growth in vitro of strains Yersinia enterocolitica, serovars 0:3, 0:5, 0:8 and 0:9, on culture media containing rhamnose, raffinose and sodium succinate and at different temperatures of cultivation (4 degrees, 25 degrees and 37 degrees C) was characterized. It was established, that all the Yersinia enterocolitica serovars tested, cultivated at 25 degrees C, had the highest growth rate. A significant activation of growth at this temperature was observed when L-rhamnose and especially sodium succinate were used as substrates.