Pigs were divided into 4 groups of uninfected (n=9), infected with H. pylori strain J99 (n=9), strain SS1 (n=8) and SW-SS1 (n=9). Following a 12-hour fasting period, bacterial challenge was performed by orogastric gavage with 1x1010 CFU H. pylori live organisms (strains J99, SS1 or SW-SS1) resuspended in sterile brucella broth administered on days 0 and 2 of the study. As a control, the uninfected group received sterile brucella broth without any bacteria. A delay in gastric emptying was ensured by oral administration of brucella broth supplemented with fetal bovine serum (FBS) prior to the bacterial or mock challenges. To suppress gastric acidity and to increase the efficiency of H. pylori colonization, all pigs received Famotidine (1mg/kg) intramuscularly 90 minutes prior to each bacterial and control inoculation and 5% urea was added to drinking water for 4 days post-infection to provide sufficient substrate for H. pylori urease and to increase gastric pH. Pigs were monitored and scored for clinical signs of disease daily.
Peripheral blood was collected from the vena cava weekly to study systemic immune responses by flow cytometry. Pigs were euthanized between day 51 and 60 post-infection to assess gastric colonization with H. pylori, to study lesions and local immune responses in the gastric mucosa and lymph node (GLN). Tissue was collected from 3 major regions of the stomach: fundus gland (F), pyloric gland (P), cardiac gland (C) and further subdivided in 2 sections (F-A, F-B, P-A, P-B, C-A, C-B) for specific applications. Furthermore, Spleen and GLN were collected for further analysis.
Suppl Fig 1 pigstomach.tiff