Summary. Spiral-helical shaped bacteria other than Carnpylobacter pylori have been shown to infect the human stomach. The characteristic helical morphology of these bacteria appears to be similar to that of bacteria found in the stomachs of many other animal species. Early reports on gastric bacteria suggested that rodents may be useful for investigation and isolation of stomach-associated bacteria. Therefore, anaesthetised mice were given, through a stomach tube, a heavy suspension of a spiral-helical bacterium from a cat, scrapings of gastric mucus from primates, or a homogenised whole-antral biopsy from a human patient. At intervals after inoculation, gastric biopsies were examined by lightmicroscopy and electronmicroscopy for the presence of spiral-helical bacteria. Significant colonisation was observed in 40% of mice 1 week, and in 80% of mice 1 1 weeks, after inoculation with suspensions of the cat isolate. Mice were also successfully colonised by spiral bacteria present in homogenised human biopsy material and by other spiral bacteria from a monkey. These observations suggest that mice may prove to be useful animals for the study of gastric bacteria that are, as yet, non-cultivable and for analysis of some of the attributes commonly thought to be involved in colonisation.

Colonisation of the human gastric antrum with non Campylobacter pylori spiral organisms is described. A moderately severe histological gastritis was present despite the fact that these organisms, in contrast to C. pylori, were not closely associated with the epithelial cell surface. Although in vitro culture of the organisms was unsuccessful, in vivo culture was achieved in the mouse stomach. Further study of these spiral organisms should provide important clues to the role of bacteria in upper gastrointestinal disease.