Chronic atrophic gastritis in SCID mice experimentally infected with Campylobacter fetus

Campylobacter fetus is a cause of enteritis and invasive extraintestinal disease in humans. In order to develop an animal model of C.fetus infection, outbred ICR SCID mice sere orally challenged with a clinical isolate of C.fetus. The stomachs of SCID mice were heavily colonized with C. fetus, and colonization was associated with the development of chronic atrophic gastritis. This lesion was characterized by an inflammatory infiltrate of granulocytes and macrophages that over time resulted in a loss of specialized parietal and chief cells in the corpus and the appearance of a metaplastic mucous epithelium. This lesion bears similarity to that encountered during experimental murine infection with Helicobacter pylori or Helicobacter felis. Despite colonization of the cecum and colon tissues by C.fetus in SCID mice, no lesions were noted in these tissues. A follow-up study confirmed these findings for SCID mice and also demonstrated that C.fetus could also infect the gastric mucose of wild-type, outbred ICR mice. However, in ICR mice, the anatomic extent of colonization was more limited and the severity of inflammation and epithelial alterations was significantly less than that observed in infected SCID mice. The stomach may represent an unrecognized environmental niche for Campylobacter species.