Case 31. Intestinal spirochetosis (63 y-o F)
    Ascending colon biopsy from an asymptomatic female (accompanying focal redness in the colonic mucosa)    
Key words : Brachyspira aalborgi, intestinal spirochetosis
Furred, basophilic material is adhered onto the surface of the crypt epithelium (HE).   The furred, basophilic material is composed of long and coiled, argyrophilic spiral microbes named Brachyspira aalborgi (Warthin-Starry's silver).
Electron micrograph of Brachyspira aalborgi on the colonic epithelium
Another case of intestinal spirochetosis (45 y-o M). Coiled long bacteria are adhesive to the colonic microvillous surface.