A role for culture in diagnosis of Helicobacter pylori-related gastric disease.

UNLABELLED

In this study, our objective was to determine the presence of Helicobacter pylori and other rapid urease-positive (RUP) organisms in gastric biopsies in 70 patients, 30 of whom had ulcers or erosions. A retrospective chart review was undertaken to correlate diagnostic tests (culture and direct urease) with results of endoscopic examination and the patient's clinical information. Eleven of 70 (15.7%) patients' biopsies were positive by both culture and direct urease for H. pylori, seven (10%) patients' biopsies were positive by culture only, and eight (11.4%) biopsies by direct urease only. Of 30 patients with ulcers (esophageal, antral, stomach, or duodenal), 15 had evidence of H. pylori infection by culture and/or direct urease test. In addition, patients with a positive direct urease test but a negative culture for H. pylori were more likely to have other rapid urease-positive organisms (RUP) isolated from their gastric biopsy cultures than patients with negative results from both tests.

CONCLUSIONS

As a result of problems associated with commonly used diagnostic tests, a combination of tests performed on multiple biopsies is more sensitive and specific for the diagnosis of H. pylori infection than any single test. The common occurrence of RUP streptococcal and staphylococcal species in gastric biopsy tissue is demonstrated and proposed as a cause of false-positive direct urease tests.