[Pathogenic properties of Yersinia pseudotuberculosis in different biological models]

The study of the action of Y. pseudotuberculosis introduced into the cavity of the ligated intestinal loop of a rabbit, into the stomach of 2- to 4-day-old suckling mice or injected intradermally has made it possible to establish the importance of the invasive and toxic activity of this microbe in the pathogenesis of pseudotuberculosis infection. The lesion of the small intestine develops due to the penetration of the bacteria into the mucous membrane and the combined action of the microbial cells inhabiting the stroma, and secreting into the environment of cytotoxins, toxic substances with an enterotropic action or enterotoxins and factors increasing the permeability of the vessels. Y. pseudotuberculosis strains with high and low invasiveness have been isolated.