Studies on the pathogenicity of Yersinia enterocolitica. II. Interaction with cultured cells in vitro.

Analysis of the pathogenicity of Yersinia enterocolitica was performed by means of cell culture studies on the interaction of the organisms with HeLa cells and rabbit peritoneal macrophages based on observations of the pathogenic behavior of the organisms in vivo (II). The pathogenic strains, which successfully produced experimental enterocolitis in rabbits (II), had the ability to penetrate HeLa cells and to survive or multiply within the macrophages. The nonpathogenic strains, lacking the ability to produce pathological changes in rabbits (II), failed to penetrate HeLa cells, except for one strain, and also to survive totally or multiply within the macrophages. It was evident that the abilities of the organisms to penetrate epithelial linings which serve as the barrier of intestinal mucosa and to survive or multiply within the host cells appears to be closely related to the pathogenicity of Y. enterocolitica.