Novel intestinal Helicobacter species isolated from cotton-top tamarins (Saguinus oedipus) with chronic colitis

A disease similar to ulcerative colitis in humans has been identified in co tton-top tamarins (CTTs) in captivity. The clinical signs include weight lo ss, diarrhea, and rectal bleeding with the pathological features and bioche mical abnormalities of ulcerative colitis. Approximately 25 to 40% of these animals develop colon cancer after 2 to 5 years of captivity. An infectiou s etiology has been proposed; however, no microbial agent to date has been identified. Helicobacter spp. have been associated with enterocolitis and i nflammatory bowel disease (IBD) in humans and animals. Infection with Helic obacter pylori or Helicobacter mustelae is associated with an increased ris k of gastric adenocarcinoma and lymphoma of the mucosa-associated lymphoid tissue. Helicobacter hepaticus causes hepatitis, hepatic adenomas, and hepa tocellular carcinomas in susceptible strains of mice. The aim of this study was to assess a colony of CTTs with a high incidence of IBD and colon canc er for the presence of colonic Helicobacter spp, A fusiform, gram-negative bacterium,vith bipolar flagella and periplasmic fibers was isolated from th e feces of CTTs, The bacterium grew under microaerobic conditions at 37 and 42 degrees C but not at 25 degrees C, did not hydrolyze urea, was positive for catalase and oxidase, did not reduce nitrate to nitrite, did not hydro lyze indoxyl acetate or alkaline phosphatase, and was resistant to nalidixi c acid, cephalothin, and trimethoprim-sulfamethoxazole. On the basis of 16S rRNA gene sequence analysis, the organism was classified as a novel Helico bacter species. This is the first Helicobacter isolated from CTTs. Further studies are needed to elucidate the role of this novel Helicobacter sp, in the pathogenesis of ulcerative colitis and colonic adenocarcinoma in CTTs.