2000 Volume 62 Issue 9 Pages 947-951
Seven adult free−ranging sika deer(Cervus nippon yesoensis)were examined by histology, immunohistochemistry and electron microscopy for intestinal spirochetal infection.Histologically epithelial and goblet cell hyperplasia and edema of the lamina propria mucosa with macrophage and lymphocyte infiltration were observed in the cecum and colon in 6 of the 7 deer.Numerous argyrophilic spirochetes were present in the crypts and some had invaded epithelial and goblet cells and caused degeneration.Immunohistochemically the organisms stained positively with polyclonal antisera against Brachyspira(Serpulina)hyodysenteriae and B.pilosicoli.Ultrastructurally they were 6−14 μm long, 0.2−0.3 μm wide and had 4−6 coils and 13 axial filaments per cell;such features were closely similar to those in the Brachyspira species.These results showed that the spirochetes were capable of inducing enteritis in deer and this intestinal spirochete infection might already be prevalent among wild sika deer in Japan.There is a possibility that this spirochetal colitis is a new syndrome in sika deer and that the same and/or similar spirochetes have infected ruminants, including sika deer and cattle.