An animal model of Helicobacter pylori infection was obtained with Mon
golian gerbils. Culture broth of H. pylori ATCC 43504 was orally admin
istered to the gerbils. Animals were killed 1, 7, 14, 21, and 42 days
after the oral inoculation and the stomachs were excised. Colonization
of H. pylori was maintained in the stomachs of all animals throughout
the study period of up to 42 days. On microscopic examination after i
mmunological and hematoxylin and eosin staining, the organisms were de
tected in the mucus layer of the gastric epithelium. All gerbils exhib
ited a slowly progressive but typical gastritis, showing superficial e
rosion with increasing numbers of infiltrating neutrophils and mononuc
lear cells. Forty-two days after the inoculation, lymph follicles were
detected in the gastric submucosa. These features are similar to the
manifestations of H. pylori infection in humans and, accordingly, this
model could be of value for studying H. pylori pathogenicity and for
research into agents for the treatment of H. pylori infection in human
s.