Figure 1.

Patterns of inflammation, colonization, and acid survival induced by archival versus recent Helicobacter pylori J99 isolates. A, Two antral biopsy specimens were obtained at each endoscopy from a single site 2–6 cm from the pylorus on the greater curvature of the stomach and were used for histopathologic examination. Similarly, 2 corpus biopsy specimens were obtained at each endoscopy from a single site 6–10 cm proximal to the termination of the gastric rugae on the greater curvature of the stomach. For each specimen, 10 high-powered fields were examined. Acute and chronic inflammation were each graded 0–3 in the gastric antrum and corpus, for a cumulative score ranging from 0 to 6, and data represent mean histologic scores from the 2 biopsy specimens at each site at each point in time. *P < .05; ^†P < .01. B, Mongolian gerbils were challenged with the H. pylori archival or recent J99 strains. Two weeks after infection, they were euthanized, and their stomachs harvested. One-fourth of the stomach was homogenized in sterile phosphate-buffered saline, as reported elsewhere [10]. After serial dilution, samples were plated on selective trypticase soy agar plates with 5% sheep blood containing vancomycin, nalidixic acid, bacitracin, and amphotericin B and were incubated at 37°C with 5% carbon dioxide for 5–7 days. Colonization efficiency was expressed as the percentage of gerbils colonized versus the percentage gerbils challenged (n = 5 per group). ^‡P = .04. C, Colonization density in wild-type C57Bl/6 mice (n = 5 per group) was determined by means of quantitative culture. ^§P = .008. CFUs, colony-forming units (CFUs). D, Archival and recent J99 strains were cultured in Brucella broth adjusted to a pH of 5.0 or 7.0 and incubated for 60 minutes. Bacteria were then plated by serial dilution, and colonies were counted. ^§P = .008. Abbreviation: NS, not significant.