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.

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.

[The invasive properties of Escherichia coli O18 in relation to cell cultures and infections in inbred mice]. / Prouchvaniia vurkhu invazionnite svoistva na Escherichia coli O18 po otnoshenie na kletuchni kulturi i pri infektsii u inbredni mishki.

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 development of the infectious process and the changes in the number of bacteria in the viscera of the inoculated mice for both ways of introduction of the agent were of the same type. The infectious process after subcutaneous inoculation was accompanied with serious orchitis and progressive inflammatory necrotic changes in the inoculated paws leading to demarcation of the whole limb.

[Yersinia enterocolitica--its multiplication on nutrient media containing rhamnose, raffinose and sodium succinate]. / Yersinia enterocolitica--razmnozhavane v khranitelni sredi, sudurzhashti ramnoza, rafinoza i natriev suktsinat.

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. The cultivation at 37 degrees C caused a sharp increase in the growth rate which, however, decreased at the end of the experiment (96th hour of cultivation), and certain stimulation of growth was observed on D-raffinose-containing medium. The growth of cells cultivated at 4 degrees C using L-rhamnose as substrate started after a lag-phase of 24 hours, which was better expressed for serovars 0:8 and 0:9. The results reported could be applied to experiments, using methods of isolation of Yersinia enterocolitica from different sources after cultivation at 4 degrees C on L-rhamnose-containing media.

[The in vitro multiplication kinetics of Yersinia pseudotuberculosis--the effect of rhamnose, raffinose and sodium succinate]. / Kinetika na razmnozhavaneto in vitro na Yersinia pseudotuberculosis--efekt na ramnoza, rafinoza i natriev suktsinat.

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. The studies on the effect of different substrates on the growth of Yersinia pseudotuberculosis in a wide temperature range acquire great importance for the investigating of the process of infection, revealing some aspects of the microorganism-macroorganism relationship.