Gastritis and intestinal metaplasia in Syrian hamsters infected with Helicobacter aurati and two other microaerobes

Chronic gastritis and intestinal metaplasia associated with naturally occur ring colonization by Helicobacter aurati and two other microaerobic species were observed in Syrian hamsters. Thirty-five hamsters, between 7 and 12 m onths of age, were evaluated from two research and three commercial facilit ies. Microaerobic bacteria were cultured from the hamster stomachs. These b acteria included H. aurati, a fusiform, urease-positive species; a second n ovel helical, urease-negative Helicobacter sp.; as well as a smaller, ureas e-negative Campylobacter sp. Southern blot analysis detected Helicobacter s pp. DNA in the gastric tissues of all 35 hamsters; 15 hamsters also had Cam pylobacter sp. DNA in their gastric tissues. When examined by light microsc opy, argyrophilic bacteria consistent with H. aurati or the second Helicoba cter sp. were present in antral sections of 12 out of the 15 hamsters where bacteria were seen, while 9 out of the 15 hamsters had bacteria resembling the Campylobacter sp. The presence of Helicobacter spp. but not the presen ce of Campylobacter sp. was significantly correlated to gastritis severity (P < 0.0001 for Helicobacter spp., P = 0.6025 for Campylobacter sp.) and in testinal metaplasia, as measured by numbers of goblet cells (P = 0.0239 for Helicobacter spp., P = 0.5525 for Campylobacter sp.). Severely affected ha msters also had Giardia sp. within their metaplastic gastric pits. Hamsters with naturally occurring helicobacter-associated gastritis provide a model for studying the development of intestinal metaplasia and gastric giardias is in H. pylori-infected humans.