SEVERE GASTRITIS IN GUINEA-PIGS INFECTED WITH HELICOBACTER-PYLORI

An appropriate animal model is essential to study Helicobacter. pylori infection. The aim of this study was to investigate if H. pylori can colonise the guinea-pig stomach and whether the infection causes gastr itis and a serological response similar to that observed in man. Guine a-pigs were infected either with fresh H, pylori isolates from human g astric biopsies or with a guinea-pig passaged strain. When the animals were killed, 3 and 7 weeks after inoculation, samples were taken for culture, histopathology and serology. H. pylori was cultured from 22 o f 29 challenged animals. All culture-positive animals exhibited a spec ific immune response against H. pylori antigens in Western blotting an d gastritis in histopathological examination. Antibody titres in enzym e immunoassay were elevated among animals challenged with H, pylori. T he inflammatory response was graded as severe in most animals and cons isted of both polymorphonuclear leucocytes and lymphocytes. Erosion of the gastric epithelium was found in infected animals. These results s uggest that the guinea-pig is suitable for studying H. pylori-associat ed diseases. Moreover, guinea-pigs are probably more similar to man th an any other small laboratory animal as regards gastric anatomy and ph ysiology.