Experimental infection of gnotobiotic mice with Campylobacter jejuni: colonisation of intestine and spread to lymphoid and reticulo-endothelial organs.

Axenic and monoxenic C3H mice were used to develop an animal model for enteroinvasiveness and translocation of Campylobacter jejuni. After oral administration of 10(7)-10(8) viable cells of C. jejuni on day 0 (D0), bacterial colonisation was followed quantitatively during 23 days by counting free luminal bacteria and tissue-associated bacteria in the duodenum, ileum and colon. The kinetics of bacterial colonisation were the same in axenic and monoxenic mice; bacteria were more numerous in distal than in proximal intestinal segments. Electronmicroscope studies of axenic infected mice showed C. jejuni free in the intestinal lumen on D2 and D7, and adhering to microvilli or included in enterocyte vacuoles in the colon on D2 without inflammatory reaction; C. jejuni was isolated from mesenteric lymph nodes until D23, but from blood, spleen, liver and bile until D1 only. In monoxenic infected mice, C. jejuni was found from D1 to D4 in mesenteric lymph nodes and Peyer's patches, whereas the associated bacterium (Clostridium perenne) was never cultured from any organs. On the basis of our observations in this gnotobiotic model, C. jejuni appears to be an enteroinvasive bacterium with a particular affinity for lymphoid organs.