Demonstration of Helicobacter pylori-like organisms in the gastric mucosa of captive exotic carnivores.

Samples of gastric tissue from the cardiac, fundic and pyloric region of 30 carnivores comprising 12 tigers (Panthera tigris), 10 lions (Panthera leo), three pumas (Felis concolor), two leopards (Panthera pardus), one serval (Felis serval), one wolf (Canis lupus) and one hyena (Crocuta crocuta) kept at German zoological gardens were subjected to histopathological and immunohistochemical examination. Selected tissue specimens of 12 animals were examined also by electron microscopy. The purpose of this study was to determine the prevalence of Helicobacter-like organisms in carnivores and to record infection rates, degree of colonization and associated histopathological changes. Three morphologically different types of spiral-shaped bacteria were demonstrated. A Helicobacter pylori-like organism (HPLO) was found in 42% of the tigers and 90% of the lions examined. Large Helicobacter-like organisms (HLOs) were identified in three pumas, one serval, one hyena and in three lions (in the latter, in coexistence with HPLOs). A third organism with a spiral periplasmic fibril (Helicobacter felis-like) was demonstrated in a wolf. The most striking histopathological finding associated with HPLO and HLO colonization was the formation of lymphoid follicles in the mucosa. Additional lymphoplasmacytic and neutrophilic infiltrates in the gastric mucosa were found in a number of tigers and lions infected with HPLOs, but none in the other carnivores infected with HLOs. From these results it is concluded that gastric bacteria similar or identical with H. pylori may also be an important cause of chronic gastritis in tigers and lions.