Morphology of intestinal colonization of Yersinia enterocolitica serovar O3 in mice

The present study was made to know the morphology of the initial invasion a nd lesions involved in the intestinal colonization of Yersinia enterocoliti ca serovar O3 in the epithelium of Peyer's patches of mice. Microfold (M) c ells formed a specific structure like a pseudopodium and the bacteria were observed on the surface of the pseudopodium-like structure 4 hr after oral administration of serovar O3. The colonies of serovar O3 were observed in t he epithelium and the lamina propria of the Peyer's patches dome region, an d the bacteria grown in the Peyer's patches were in direct contact with the lumen without covered with the host tissue 24 hr after the administration.