Prevention and treatment of Helicobacter pylori infection with adhesin conservatory region vaccine: an animal model study

AIM: To investigate the effects of Helicobacter pylori (H pylori) adhesin conservatory region vaccine in the pre- vention and treatment of H pylori infection in a mouse model. METHODS: The study was divided into two parts. In the first part, the specific germ free C57BL/6 mice were orally immunized with vaccine (100 µg) plus cholera toxin (CT) (2 µg), vaccine (100 µg), CT(2 µg), or PBS once a week for four weeks. Two weeks after the last immunization, all animals were challenged by live H pylori, and were sacrificed 4 weeks after the challenge. In the second part, H pylori infected mice were treated in the same way as in the first part. Four weeks after the last treatment, all animals were sacrificed, and the stomach biopsies were collected to detect H pylori by the semi-quantitative bacterial culture assay. RESULTS: The prophylactic rate from H pylori infection was 61.5% (16/26) in the mice immunized with vaccine plus CT. The eradication rate of the vaccine plus CT group was 38.5% (10/26). No protective or therapeutic effect was observed in all other 3 groups. The H pylori colony density in the vaccine plus CT group was significantly lower than those inother three groups in the second part of experi- ment (P<0.05).