Comparison ofHelicobacterspp. in Cheetahs (Acinonyx jubatus) with and without Gastritis

Abstract

Chronic gastritis causes significant morbidity and mortality in captive cheetahs but is rare in wild cheetahs despite colonization by abundant spiral bacteria. This research aimed to identify the Helicobacter species that were associated with gastritis in captive cheetahs but are apparently commensal in wild cheetahs. Helicobacter species were characterized by PCR amplification and sequencing of the 16S rRNA, urease, and cagA genes and by transmission electron microscopy of frozen or formalin-fixed paraffin-embedded gastric samples from 33 cheetahs infected with Helicobacter organisms (10 wild without gastritis and 23 captive with gastritis). Samples were screened for mixed infections by denaturant gel gradient electrophoresis of the 16S rRNA gene and by transmission electron microscopy. There was no association between Helicobacter infection and the presence or severity of gastritis. Eight cheetahs had 16S rRNA sequences that were most similar (98 to 99%) to H. pylori. Twenty-five cheetahs had sequences that were most similar (97 to 99%) to "H. heilmannii" or H. felis. No cheetahs had mixed infections. The ultrastructural morphology of all bacteria was most consistent with "H. heilmannii," even when 16S rRNA sequences were H. pylori-like. The urease gene from H. pylori-like bacteria could not be amplified with primers for either "H. heilmannii" or H. pylori urease, suggesting that this bacteria is neither H. pylori nor "H. heilmannii." The cagA gene was not identified in any case. These findings question a direct role for Helicobacter infection in the pathogenesis of gastritis and support the premise that host factors account for the differences in disease between captive and wild cheetah populations.Since the initial isolation of Helicobacter pylori from humans and its association with gastritis and peptic ulceration (23), Helicobacter spp. have been isolated from an ever-expanding range of host species (38). While Helicobacter pylori infection in humans has been associated with chronic gastritis, peptic ulceration, gastric adenocarcinoma, and lymphoma (23,31,32), Helicobacter pathogenicity in many species is less clear.

Gastric Helicobacter spp. infection in captive neotropical Brazilian feline

“…By contrast, others researches found no association between infection and gastric mucosal inflammatory infiltrate, suggesting that the bacteria are commensal or opportunist pathogens (7,23). Also, the study of 28 semi captive cheetahs found out mild or no lesions in 27, concluding that gastritis was uncommon in these animals and…”

“…In captive wild feline animals stress and host factors might be important issues in the development of gastritis associated with Helicobacter infection (23). The presence of Helicobacter spp.…”

Characterization of the Gastric Immune Response in Cheetahs (Acinonyx jubatus) WithHelicobacter-Associated Gastritis

“…is a major cause of morbidity and mortality in captive cheetah populations. 5,[9][10][11]38,39,54 This reaction is unlike that seen in free-ranging cheetahs or other felid species (both domestic and zoo held) that usually only develop mild inflammatory lesions when infected with similar Helicobacter. 20,24,25,27,29,30,40,44,49,54,58 The lesions in cheetahs occur predominantly in the gastric fundus and are characterized by florid lymphocyte and plasma cell infiltrates, infiltration of glandular epithelium, parietal cell apoptosis and, in more chronic cases, may include gland hyperplasia, goblet cell metaplasia, fibrosis and/or atrophy.…”

Fatal Septicemia Caused by Helicobacter Infection in a Pancake Tortoise (Malacochersus Tornieri)

“…In mammals and birds, Helicobacter have been associated with gastric ulcers, ulcerative colitis, cholangiohepatitis, cellulitis, and bacteremia. 5,7,10 Reported cases of infection by spiral bacteria in reptiles are very limited. The first documented case described the detection and ultrastructural characterization of spiralshaped bacteria associated with septicemia in a moribund rhinoceros iguana (Cyclura cornuta).…”