In situ detection of urease-positive Helicobacter pylori-like organisms on swine gastric mucosa.

The objective of this study was to improve the visual localization of urease activity of Helicobacter pylori-like organisms (HPLO) on swine gastric mucosa by in vitro optimization of the urea concentration and pH indicator of a urease test reagent. Five 21-day-old conventional pigs were infected orally with HPLO (3 pigs) or Brucella broth alone (2 pigs). At 17 d after infection the pigs were euthanized and their stomachs excised and tested for HPLO by a modified urease test formulation sprayed onto the gastric mucosa, as well as confirmatory culture and isolation of HPLO from urease-positive sites. This study showed improved detection of HPLO in porcine gastric mucosa with the use of a modified urease test formulation containing 5% urea and the pH indicator bromocresol purple compared with the use of a conventional formulation of 2% urea and phenol red. This test can readily be applied to achieve a presumptive diagnosis of HPLO in cases of gastritis or gastric esophageal ulceration in pigs.