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
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
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