Comparison of three urease tests for detection of Helicobacter pylori in gastric biopsy specimens

Abstract

Objective: To propose two modified urease tests for the detection of Helicobacter pylori in gastric biopsy specimens.

Patients and methods: The presence of H. pylori infection was determined in 237 patients undergoing upper gastrointestinal endoscopy. Three media were used for the urease tests: Christensen's 2% urea broth and two urea agar media, modified by increasing the concentration of urea (to 4% and 10%) and phenol red and omitting the nutrients.

Results: The modified tests had good sensitivity (> 78%), specificity (96%) and accuracy (> or = 86%) at 2 h using small amounts (15%) of biopsy homogenates. They were statistically more sensitive and accurate than Christensen's broth.

Conclusion: Both the modified 4% and 10% urea agar tests are simple, sensitive and specific and can be performed with small amounts of sample.