Identification of Helicobacter sp. From the Gastric Mucosa of Stranded Bottlenose Dolphins (Tursiops truncatus), with Gastric Ulcers
IAAAM Archive
Claudia Harper1; Yan Feng1; Barbara Sheppard1; James G. Fox1; Charles Potter2
1Massachusetts Institute of Technology, Division of Comparative Medicine, Cambridge, MA; 2Smithsonian Institution, Marine Mammal Program, Washington, DC


Gastric ulcers have been reported in wild and captive dolphins for decades.1 Some lesions have been associated with parasitic infections and others had no clearly defined etiology.2,8,10-13

Gastric Helicobacter sp. are important pathogens causing chronic gastritis, peptic ulcers, gastric adenocarcinoma and lymphoma in humans and a wide variety of animals.3-7 Helicobacter infected humans and animals do not always exhibit clinical signs; however, histological analysis of gastric biopsies confirms inflammation induced by the presence of these bacteria.

Novel Helicobacter sp. have been isolated and characterized in stranded dolphins' inflamed stomach tissues.9 These findings suggest that a novel Helicobacter sp. is associated with the etiopathogenesis of gastritis. However, speculation still exists as to whether dolphins have Helicobacter sp. associated peptic ulcer disease.

The stomachs of 9 stranded bottlenose dolphins with gastric ulcers in either, or both the main and the pyloric stomach were assessed by PCR for the presence of Helicobacter sp. Helicobacter sp. similar to the previously described dolphin Helicobacter sp. were identified by PCR and RFLP in the gastric mucosa of 8 dolphins studied. Partial 16S rRNA sequence analysis clustered with gastric helicobacters including the previously described dolphin Helicobacter spp.9

These findings suggest that Helicobacter sp. may play a role in the etiopathogenesis of gastric ulcers in dolphins. To our knowledge this represents the first identification and characterization of a novel dolphin Helicobacter sp. from stranded bottlenose dolphins with gastric ulcers in the glandular mucosa.


This work was supported in part by R01-AI37750 and T32-RR07036. The authors wish to thank Ms. Diane Pitassy from the Smithsonian Institution for her support during this project.


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Speaker Information
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Claudia M.G. Harper, DVM
Tufts University School of Veterinary Medicine
North Grafton, MA, USA