Spreading of Salmonella enteritidis in the cecum of chickens.

Adhesion and colonization of high (2 x 10(8) CFU) and low doses (2 x 10(2) CFU) of Salmonella enteritidis (phage type 4) was determined in the ceca collected 6 h-4 weeks after inoculation (pi), of 1-d-old White Plymouth Rock orally-inoculated chickens. S. enteritidis was associated with the epithelial surface of the villi in the low-dose group 18 h-7 d pi, the penetration in the cecal lamina propria was observed on day 1 and 10 pi. In the high-dose group, adhesion and colonization was observed in all birds killed 6 h-14 d pi; penetration of the bacteria into the cecal lamina propria was seen 1-21 d pi. Large numbers of macrophage-like cells containing S. enteritidis were observed in the cecal lamina propria on days 3-21 pi. Colonization and migration by S. enteritidis in the intestinal tract of chickens was shown to be dose dependent.