GASTROINTESTINAL COLONIZATION OF BALB CA MICE BY HELICOBACTER-PYLORI MONITORED BY HEPARIN MAGNETIC SEPARATION/

Immunocompetent and immunodeficient BALB/cA mice were fed orally with 10(8) colony forming units of 2-day-old spiral or coccoid (12 days old ) Helicobacter pylori strain NCTC 11637. Immunocompetent BALB/cA mice were also fed orally with decreasing numbers. of spiral or coccoid for ms of H. pylori. The gastrointestinal colonisation process was monitor ed for 34 days post-infection by heparin magnetic separation and subse quent enzyme immunoassay (EIA) for the detection of the H. pylori cell s. Both mice types were colonised with H. pylori. The coccoid form of H. pylori gave higher EIA absorbance values and more efficient colonis ation in the mice than the spiral form. Immunocompetent BALB/cA mice f ed with the coccoid form of H. pylori exhibited an acute inflammation process in histopathological samples from the stomachs. In conclusion, H. pylori can infect both immunocompetent as well as immunodeficient BALB/cA mice and coccoids (viable but non-culturable) obtained after 1 2 days of culturing can infect BALB/cA mice.