INFECTION OF BALB C A MICE BY SPIRAL AND COCCOID FORMS OF HELICOBACTER-PYLORI/

Helicobacter pylori exists in two different morphological forms, spira l and coccoid, This study demonstrated that both forms can infect BALB /c A mice, The animals were inoculated orally three times at 2-day int ervals with 10(8) cfu of both spiral and coccoid forms of strain CCUG 17874 (NCTC 11637), strain 25 and strain 553/93. Infection was followe d over a 30-week period by histological scoring of the grade of inflam mation in gastric biopsies, At each time point sera were collected for analysis in ELISA and immunoblot analysis, Both spiral and coccoid fo rms of all H. pylori strains gave significantly higher inflammation sc ores than a control group of animals I week after inoculation. The his tological evidence persisted throughout the entire 30 weeks, The infla mmation was most severe in the pylorus and duodenum, Infection with st rain 553/93 displayed the most severe gastritis. The spiral form of st rain CCUG 17874 gave an immune response after only 4 weeks, whereas it s coccoid form as well as strains 25 and 553/93 (spiral and coccoid fo rms) gave a significant increase in antibody response in ELISA and imm unoblot after 16 weeks. It is concluded that both spiral and coccoid f orms of H. pylori can cause acute gastritis in BALB/c A mice.