Total of 30 domestic stray cats (Felis cattus) were investigated for the presence of different species of gastric Helicobacter-like organisms (GHLO) by immunohistochemistry and polymerase chain reaction (PCR) analysis. The severity and distribution of pathologic changes in different regions of stomach were assessed microscopically. GHLO were present in all areas of the stomach in 93.3% cats investigated. Morphologically two different types of spiral bacteria were recognized. In 53.3% cats H. felis like organisms and in 76.7% cats H. heilmannii like organisms were determined. Mixed presence of both bacteria was seen in 43.3% cases. H. pylori was not detected in any of the cats. Mild to severe gastritis were observed in 90.0% cats. GHLO were present in fundus, corpus and pyloric antrum regions in similar densities. The most striking histopathological changes were lymphocyte and neutrophil infiltrations, fibrosis in the lamina propria, and lymphoid follicle formation. There was no significant relationship between the degree of bacterial density and the extent of histopathological changes. GHLOs were present on the mucosal surface, in the lumen of gastric glands, and in the cytoplasm of parietal cells. In conclusion, PCR and immunohistochemistry can be successfully used in detection of GHLOs. The results of the study show also that H. heilmannii and H. felis are frequent agents in stray cats, and hence suggest that these animals might be common reservoirs for these microorganisms. However, the bacteria do not seem to be solely responsible for gastritis observed in some stray cats.

Key words: Cat, Gastritis, Helicobacter, Immunohistochemistry, PCR