CHARACTERIZATION OF FELINE HELICOBACTER-PYLORI STRAINS AND ASSOCIATEDGASTRITIS IN A COLONY OF DOMESTIC CATS

Twenty-four young adult domestic cats from a commercial vendor were fo und to be infected with Helicobacter pylori. Histopathologic analyses, selected electron microscopy, and urease mapping were performed on mu cosal samples collected from the cardias and fundi, bodies, and antra of these cats' stomachs, Pi pylori organisms were abundant in all area s of the stomach on the basis of histologic evaluation and urease mapp ing. Pi. pylori infection was associated with a moderate to severe lym phofollicular gastritis in 21 of 24 cats (88%). The gastritis was most pronounced in the antral region and consisted mainly of multifocal ly mphoplasmacytic follicular infiltrates in the deep mucosa. The severit y of gastritis in the antrum corresponded to high numbers of H. pylori there on the basis of the use of the urease assay as an indicator of H. pylori colonization. Ten of 24 cats (42%) also had small to moderat e numbers of eosinophils in the gastric mucosa. All 24 cats had gastri c lymphoid follicles, with follicles being most prevalent in the antru m, Electron microscopy of gastric tissue revealed numerous H. pylori o rganisms, some of which were closely adhered to the mucosal epithelium . Human H. pylori gene-specific primers to ureA and ureB amplified pro ducts of similar sizes from H. pylori cat isolates, Digestion of the p roducts with restriction enzymes resulted in fragments characteristic of the restriction fragment length polymorphism patterns of H. pylori isolates from humans, In the domestic cat, H. pylori infection is asso ciated with a lymphofollicular gastritis, consisting of lymphocytic an d plasmacytic infiltration into the lamina propria, and the organism a ppears to provide chronic antigenic stimulation resulting in the forma tion of gastric lymphoid follicles.