[The urease test for the diagnosis of Campylobacter pylori infection]

To evaluate the usefulness of urea media routinely applied in the diagnosis of Campylobacter pylori infection, 50 patients with gastroduodenal pathology were studied. Two biopsies of antral mucosa were taken; one of them was placed on Urea Agar Base (Difco) prepared without agar, and the other in saline for Gram staining and culture in selective and enriched media. In 39 patients Campylobacter pylori was found by Gram staining and/or culture. 38 of them were urease test positive, 24 (61.5%) during the first hour, 8 (20.5%) between the first and fourth hours and 6 (15.3%) between 4 and 24 hours. The sensitivity of the test increased from 61.5% at the first hour to 82.0% and 97.3% at 4 and 24 hours, respectively. The specificity was 100% for all the readings. We believe that the urease test with medium of Urea Agar Base is useful for the diagnosis of Campylobacter pylori infection. However, we recommend the selection of two or three combined methods for better confirmation of the infection.