Naturally occurring chronic gastritis and C pylori infection in the rhesus monkey: a potential model for gastritis in man.

Histological examination of the stomachs of Rhesus monkeys at autopsy showed chronic gastritis in a high proportion of all ages. Lesions consisted of mild to heavy infiltration of the lamina propria by lymphocytes, plasma cells, and histiocytes. The antrum was most consistently affected, but lesions were also present in the fundus and pylorus. Gastric Campylobacter-like organisms (GCLO) apparently identical to human C pylori were cultured and/or detected immunohistologically in several animals. Electron microscopy showed the spiral bacteria on the epithelial surface and in gastric pits. They did not penetrate the cells but were intimately attached to the apical plasma membrane and caused loss of microvilli. Antibodies to C pylori were detected in serum of the monkeys by ELISA. The immunospecificity of this antibody response was confirmed by Western blotting techniques. A small number of cynomolgus monkeys examined had gastritis, which may also be associated with the presence of C pylori. Baboons did not have gastritis, nor was C pylori cultured from their stomachs. The study indicates that the Rhesus monkey has a naturally occurring gastritis associated with C pylori infection and may therefore be a suitable experimental animal for the human disease.