Abstract
Gastric ulcers have been reported in wild and captive cetaceans for many decades.1,2,6,7,8-10 Lesions were most often noted in the esophagus, fore stomach and glandular mucosa. These gastric ulcers were associated with parasitic infections and foreign bodies; however, in other cases, no clearly defined etiologies were identified.1,6,8-10
Gastrointestinal Helicobacter spp. are pathogens causing chronic gastritis, peptic ulcers, gastric adenocarcinoma and lymphoma in humans and a wide variety of animals.3-5 Helicobacter does not always cause clinical signs in humans and animals. A novel dolphin Helicobacter sp. associated with gastritis was recently isolated and characterized.7 However, the role of Helicobacter spp. in the development of gastric ulcers and clinical disease in cetaceans requires further study.
The gastric fluid and feces of three belugas maintained in an aquarium were assessed for the presence of Helicobacter spp. by PCR and micro aerobic culture. Helicobacter sp. similar to the previously described dolphin Helicobacter sp. was isolated by culturing the feces, and identified by PCR and RFLP in the gastric fluid and feces of one beluga. The two other animals were negative for Helicobacter spp. Interestingly, the two Helicobacter negative belugas did not exhibit clinical signs and esophageal and fore stomach lesions were not seen on endoscopy. The Helicobacter-positive animal manifested clinical signs including intermittent in appetence and lethargy. Endoscopy revealed esophageal and fore stomach ulcers.
These findings provide additional data to support a role of Helicobacter spp. in the development of gastric disease in cetaceans. To our knowledge this represents the first identification of Helicobacter spp. in a whale, and the first successful attempt to culture and characterize the organism from the feces and gastric fluid of any cetacean. The isolation of a gastric Helicobacter from the feces suggests that fecal-oral transmission may be important in the epizootiology of this disease in marine mammals.
Acknowledgements
This work was supported in part by NIH grants R01-AI37750 and T32-RR07036. We thank Ms. Gayle Sirpenski, Dr. David St. Aubin, and the marine mammal team from Mystic Aquarium for their help and expertise.
References
1. Abollo, E. 1998. Long-term recording of gastric ulcers in cetaceans stranded in the Galician (NW Spain) coast. Dis. Aquat. Org. 32:71-73.
2. De Guise, S. A. Lagace, P. Beland, C. Girard, R. Higgins. 1995. Non-neoplastic lesions in beluga - whales (Delphinapterus leucas) and other marine mammals from the St Lawrence Estuary. J. Comp. Pathol. 112(3):257-71
3. Fox, J. G. 1997. The expanding genus of Helicobacter: Pathogenic and zoonotic potential. Semin, Gastrointest. Dis. 8: 124-141.
4. Fox, J~ G. 1998. Helicobacter species and in vivo models of gastrointestinal cancer. Aliment. Pharmacol. Ther. 12:37-60.
5. Fox, J: G., R. P. Marini. 1999. Animal model of Helicobacter (Ferrets). Handbook of Animal Models of Infection. Chapter 31 .Academic Press. p.274-284.
6. Geraci, J. R., K. Gerstmann. 1966. Relationship of dietary histamine to gastric ulcers in the dolphin. JAV MA. 149:884-890.
7. Harper, C. M., C. Dangler, A. Stamper, J. G. Fox, et al. 2000. Isolation and characterization of Helicobacter sp. from the gastric mucosa of dolphins, Lagenorhynchus acutus and Delphinus delphis. Applied and Environmental Microbiology Nov 2000. P.4751-4757
8. Herreras, M. V., S. E. Kaarstad, J. A. Balbuema, C. C. Kinze. 1997. Helminth parasites of the digestive tract of the harbor porpoise Phocoena phocoena in Danish waters: a comparative geographical analysis. Dis. Aquat. Org. 28" 163-167.
9. Ridgway, S. H. 1968. The Bottlenose Dolphin in Biomedical Research. In Methods of Animal Experimentation, Volume III. Gay, W. I. Academic Press, New York. p. 435.
10. Sweeney, J. C., Ridgway, S. H. 1975. Common Diseases of Small Cetaceans. JAVMA 167:533-540.