Four groups of 23 one-day-old broiler chickens were each inoculated by gavage with a different Helicobacter pullorum strain isolated from
humans or poultry. As a control, a fifth group of eight animals was inoculated with phosphate-buffered saline. Faecal samples were collected
weekly and tested for the presence of H. pullorum DNA using PCR. At 1, 8, 15, 22 and 42 days postinoculation, birds were euthanized and
samples from the liver and intestinal tract were histologically, immunohistochemically and bacteriologically examined. The samples were also
tested for the presence of H. pullorum DNA by PCR.