Which color change indicates a positive result in the Campylobacter urease test?

In the Campylobacter urease test, a positive result is indicated by a color change to red. This transformation occurs due to the hydrolysis of urea to ammonia and carbon dioxide, which increases the pH of the medium. As the pH rises, the phenol indicator in the medium shifts to a red color, demonstrating the presence of urease activity in the bacteria being tested.

For a more comprehensive understanding, it’s helpful to note the role of the other potential indicators. A yellow color generally signals an acidic environment and would indicate a negative urease result, while colors like blue and green may not be relevant in this context or do not pertain to the urease test. The specificity of the color change to red is crucial for accurately interpreting the test results associated with Campylobacter species.