Uptake of Killed Yersinia enterocolitica by Pseudopodia of M Cells in the Peyers' Patches of the Murine Small Intestines

To understand the mechanisms of uptake of killed bacteria of Yersinia enterocolitica serovar O3 into the epithelium of Peyer's patches, the killed bacteria were perorally inoculated into mice and observation was carried out by scanning and transmission electron microscopy. Microfold (M) cells formed a specific pseudopodium-like structure and the bacteria were observed on the surface and the interior of the pseudopodium-like structure 8 hr after oral administration of killed bacteria of serovar O3.