Evaluation of Gastric Lesions Based on Helicobacter pylori and Helicobacter-Like Organisms (HLOs) in Cats; A Histopathological and Bacteriological Study

The lesions induced by Helicobacter pylori in a candidate animal model should always be examined thoroughly. The resemblance of these lesions to those observed in humans can indicate whether the usage of this model will contribute to the understanding of the various pathogenic mechanisms involved in the development of human H. pylori-associated diseases.

The aim of this study was to perform a histopathological and bacteriological evaluation of gastric lesions based on H. pylori and Helicobacter-like organisms (HLOs) in cats.

The present study was carried out on 28 cat's (13 male and 15 female cases) gastric mucosae, which were tested by bacteriological and histopathological methods. Biochemical tests such as catalase, oxidase and urease were utilized in addition to Gram and Giemsa staining.

This research demonstrated that solely one case of H. pylori was isolated by gastric mucosal culture. Microscopically, the infected stomachs by HLOs comprised a mild to severe diffuse lymphoplasmacytic infiltration into the subglandular and gastric mucosa. Lymphoid follicles were also marked, particularly within pyloric tissues and mostly in displaced mucosal glands. For 75% of the gastritis cases, both HLOs and rapid urease tests were positive, whereas 83% of cases were more than one-year-old with gastritis. Furthermore, 75% of cats indicated gastritis, though 25% encompassed no gastritis; hence 20% had negative results for the rapid urease test and 25% for the Giemsa staining test. Such results may indicate that cats without gastritis were considered as free of HLOs pathogenic bacteria.

These results suggest that most cases of gastritis were located in the antral region. Additionally, the isolation of H. pylori from domestic cats raises the possibility of zoonotic characteristics for the slightly pathogen; therefore transmission occurs from cats to human and vice versa.