Experimental Campylobacter diarrhea in chickens.

An animal model for Campylobacter fetus subsp. jejuni enteritis was developed in 3-day-old chickens. Diarrhea was induced in 88% (22 of 25) of chickens inoculated with 9 X 10(7) bacteria given orally. The mean incubation time was 45 h (range, 24 to 72 h). Considerable weight loss was observed in the experimental group compared with the control group. Ninety bacteria was the minimal infective dose capable of inducing diarrhea in 90% of the chickens. Overall mortality was 32% (8 of 25). Light microscopy, immunofluorescence, and electron microscopy of the gastrointestinal tract of serially sacrificed chickens were performed in control and experimental groups. A moderate infiltration of mononuclear cells was observed in ileum and cecum in the experimental group, with no disruption of intestinal mucosa. By immunofluorescence and electron microscopy, campylobacter was located within the epithelial cells and phagocytosed to a greater degree by mononuclear cells of the lamina propria.