. The infected captive cetaceans were either subclinical, or clinical signs included intermittent regurgitation, inappetance, weight loss, and lethargy. Ulcers were observed in the esophagus and forestomach during endoscopic examination in two of the three captive animals. In the third animal, esophageal linear erosions were visualized endoscopically, and histopathological evaluation of the main stomach revealed multifocal lymphoplasmacytic gastritis with silver-stained spiral-shaped bacteria. Helicobacter cetorum is a fusiform gram-negative bacterium with a single bipolar flagellum. The isolates grow under microaerobic conditions at 37 and 42°C but not at 25°C. H. cetorum is urease, catalase, and oxidase positive, and it is sensitive to cephalothin. The isolates from the wild, stranded dolphins were sensitive to nalidixic acid, whereas the isolates from the collection animals were resistant. By 16S rRNA sequencing it was determined that H. cetorum represented a distinct taxon that clusters most closely with H. pylori. Further studies are necessary to determine the role of H. cetorum in the development of gastric ulcers and gastritis of cetaceans. This is the first description and formal naming of a novel Helicobacter species from a marine mammal. More than 24Helicobacter species have been identified and named in a wide variety of animals, as well as in humans (13,39). Members of the genus Helicobacter are microaerobic, have a fusiform or curved to spiral rod morphology, and are motile by flagella that vary in number and location among different species (13,20,21,26,39,40). Helicobacters colonize the gastrointestinal tract of humans and animals and are known to cause gastrointestinal disease in various hosts, whereas others appear to be nonpathogenic (13,20,30). In humans, Helicobacter pylori is a significant cause of peptic ulcer disease, gastritis, and gastric tumors (25,39,40). In animals, Helicobacter spp. may cause ulcerative or nonulcerative gastritis, typhlocolitis, and hepatitis and can lead to tumors in chronic infections (13,14,17). The ability of gastric Helicobacter spp. to colonize the stomach is largely dependent on the production of urease (4). Urease hydrolyzes urea into ammonia, resulting in alkalinization of the gastric mucosa, which promotes bacterial colonization and survival (4).Gastric ulcers have been reported in cetaceans for several decades (8,33,37,38). Parasitic infections have been associated with some lesions, but in other cases no clearly defined etiologies have been identified. We previously described a novel urease-positive Helicobacter sp. cultured from the main stomachs of stranded Atlantic white-sided dolphins that died on the beach in Cape Cod, Mass., and a beluga whale from Mystic Aquarium, Conn. (23,24). Since then, additional strains of this species were cultured from the feces of a Pacific whitesided dolphin, and an Atlantic bottlenose dolphin from various aquaria in the United States (23). Based on morphological, biochemical, and growth characteristics, as well as 16S rRN...

Since the recent discovery of Helicobacter cetorum in cetaceans and its role in the development of gastritis, speculation has existed as to whether pinnipeds have Helicobacter spp. associated gastritis and peptic ulcer disease. The gastric mucosa of 4 stranded harp seals Phoca groenlandica from the Massachusetts coastline were assessed for Helicobacter spp. by culture and PCR. We cultured 2 novel Helicobacter spp. from the pyloric antrum of 1 of the 4 harp seals studied, and identified these by PCR in 2 of the 4 seals. Both gram-negative bacterial isolates were catalaseand oxidase-positive. However, a fusiform helicobacter with flexispira morphology was ureasepositive, and a spiral-shaped helicobacter was urease-negative. Slender, spiral and fusiform-shaped bacteria were detected in the gastric mucosa by the Warthin-Starry stain. Histopathologic analysis revealed mild diffuse lymphoplasmacytic gastritis within the superficial mucosa of the pyloric antrum of both infected seals. The 2 bacterial isolates were classified by 16S rRNA analysis; they clustered with other enteric helicobacters and represent 2 novel Helicobacter spp. The urease-negative bacterial isolate clustered with H. canis and the urease-positive isolate clustered with an isolate from a sea lion and isolates from sea otters. This cluster of pinniped isolates has 97% similarity to a number of Helicobacter species, but appears to be most closely related to other helicobacters with flexispira morphology. These findings suggest that the novel Helicobacter spp. may play a role in the etiopathogenesis of gastrointestinal diseases in pinnipeds. To our knowledge, this represents the first isolation and characterization of a novel Helicobacter spp. from pinnipeds. KEY WORDS: Harp seal · Pinniped · Helicobacter infection · Gastritis · Cryptosporidium Resale or republication not permitted without written consent of the publisherDis Aquat Org 57: [1][2][3][4][5][6][7][8][9] 2003 association seems to be unclear (Fox 2002, Harper et al. 2002a, Doster 2000. Recently, H. cetorum was isolated from cetaceans and thought to be involved in the development of gastritis (Harper et al. 2000(Harper et al. , 2002a.Like dogs, seals are monogastric, and gastric ulcers are usually associated with parasites and foreign bodies, although in some cases the cause of ulcers is unknown (Sweeney 1974, Bishop 1979, McClelland 1980. The distribution of harp seals ranges from the White Sea at Jan Mayen, Newfoundland, to the Gulf of St. Lawrence (Riedman 1990).The goal of this study was to determine if Helicobacter spp. could be isolated from the gastric mucosa of stranded pinnipeds. MATERIALS AND METHODS Seals.We evaluated 4 wild, stranded harp seals. All had died along the shores of New England, USA. Strandings occurred in Massachusetts in the winter of 2001, and the carcasses were collected by the New England Aquarium Marine Mammal Stranding.Sample collection. The stomach body and pyloric antrum were obtained by the submittors from 4 harp seals for culture, PCR and histop...

Helicobacter cetorum sp. nov. has been cultured from the stomach of Atlantic white-sided dolphins (Lagenorhynchus acutus) and the feces of Pacific white-sided (L. obliquidens) and Atlantic bottlenose (Tursiops truncatus) dolphins and a beluga whale (Delphinapterus leucas). H. cetorum has high homology to Helicobacter pylori as shown by 16S rRNA sequencing, and H. cetorum infection has been associated with gastritis and clinical signs in cetaceans. Because the prevalence of H. cetorum in wild populations is unknown, minimally invasive techniques for detecting H. cetorum were compared for 20 wild bottlenose dolphins sampled as part of a long-term health study. Fecal samples were tested for helicobacter by culture, Southern blotting, and PCR using genus-specific and H. cetorum-specific primers. An enzyme-linked immunosorbent assay (ELISA) was developed to measure H. cetorum immunoglobulin G (IgG). H. cetorum was cultured from 4 of 20 fecal samples, 7 samples were positive using Helicobacter sp. PCR, and 8 samples were positive for H. cetorum using speciesspecific primers. Two additional fecal samples were positive by Helicobacter sp. Southern blotting, suggesting infection with another helicobacter. All 20 sera contained high levels of IgG antibodies to H. cetorum that were significantly lowered by preabsorption of the sera with whole-cell suspensions of H. cetorum (P < 0.02). Until the specificity of the serum ELISA can be determined by testing sera from dolphins confirmed to be uninfected, PCR and Southern blot screenings of feces are the most sensitive techniques for detection of H. cetorum, and results indicate there is at least a 50% prevalence of H. cetorum infection in these dolphins.