@article {Graham1235, author = {D Y Graham and A R Opekun and M S Osato and H M T El-Zimaity and C K Lee and Y Yamaoka and W A Qureshi and M Cadoz and T P Monath}, title = {Challenge model for Helicobacter pylori infection in human volunteers}, volume = {53}, number = {9}, pages = {1235--1243}, year = {2004}, doi = {10.1136/gut.2003.037499}, publisher = {BMJ Publishing Group}, abstract = {Background: A reliable challenge model is needed to evaluate Helicobacter pylori vaccine candidates. Methods: A cag pathogenicity island negative, OipA positive, multiple antibiotic susceptible strain of H pylori obtained from an individual with mild gastritis (Baylor strain 100) was used to challenge volunteers. Volunteers received 40 mg of famotidine at bedtime and 104{\textendash}1010 cfu of H pylori in beef broth the next morning. Infection was confirmed by 13C urea breath test (13C-UBT), culture, and histology. Eradication therapy was given four or 12 weeks post challenge and eradication was confirmed by at least two separate UBTs, as well as culture and histology. Results: Twenty subjects (nine women and 11 men; aged 23{\textendash}33 years) received a H pylori challenge. Eighteen (90\%) became infected. Mild to moderate dyspeptic symptoms occurred, peaked between days 9 and 12, and resolved. Vomitus from one subject contained \>103 viable/ml H pylori. By two weeks post challenge gastric histology showed typical chronic H pylori gastritis with intense acute and chronic inflammation. The density of H pylori (as assessed by cfu/biopsy) was similarly independent of the challenge dose. A minimal infectious dose was not found. Gastric mucosal interleukin 8 levels increased more than 20-fold by two weeks after the challenge. Conclusion: Challenge reliably resulted in H pylori infection. Infection was associated with typical H pylori gastritis with intense polymorphonuclear cell infiltration and interleukin 8 induction in gastric mucosa, despite absence of the cag pathogenicity island. Experimental H pylori infection is one of the viable approaches to evaluate vaccine candidates.}, issn = {0017-5749}, URL = {https://gut.bmj.com/content/53/9/1235}, eprint = {https://gut.bmj.com/content/53/9/1235.full.pdf}, journal = {Gut} }