The inflammatory response of the gastric mucosa of mice experimentally infected with "Gastrospirillum suis"

To establish an experimental model to study gastric spiral non-cultivable bacteria, 30 4-week-old female CFW (LOB) mice were inoculated with porcine gastric mucus containing "Gastrospirillum suis" and 25 mice were inoculated with mucus without "G. suis". Mice were examined 3, 7, 14, 21, 28 and 60 days after inoculation. Fragments from the membranous, oxyntic and antral gastric mucosa and from the duodenal mucosa were obtained for histological and microbiological analysis. Tightly spiralled bacteria were seen in smears and in histological sections of the antral and oxyntic mucosa from all G. suis-infected mice. The pre-formed urease test also gave positive results in both tissues. In control mice, no tightly spiralled bacteria were seen. By 7 days after inoculation, the test animals had developed an inflammatory infiltrate of mononuclear cells, some neutrophils and a few eosinophils, mainly in the lower third of the antral and oxyntic mucosa, which persisted for the remainder of the observation period. This model can assist in the understanding of several clinical, pathological and immunological aspects of infection with spiral gastric bacteria, particularly those associated with non-cultivable spiral bacteria.