Why is the urease test useful?
Uses of Urease Test This test is used to differentiate organisms based on their ability to hydrolyze urea with the enzyme urease. It is also useful to identify Cryptococcus spp., Brucella, Helicobacter pylori, and many other bacteria that produce the urease enzyme.
What does the urea test determine in microbiology?
Urease test is a biochemical test that detects the alkaline fermentation of urine (urea) with the resultant production of ammonia by microorganisms. The fermentation of urea occurs in the presence of the enzyme ‘urease’, resulting in two molecules of ammonia and carbon dioxide.
What is the principle of urease test?
1- Rapid urease test The principle of the test is the ability of H. pylori to secrete the enzyme urease, the sample (eg gastric biopsy) is placed in a gel containing urea. The urease produced by H. pylori rapidly hydrolyzes urea, producing ammonia, which causes the indicator to change color.
What purpose does a buffer serve in urea broth specifically?
Members of the genus Proteus are included among these organisms. Urea broth is formulated to test for rapid urease-positive organisms. The restrictive amount of nutrients coupled with the use of pH buffers prevent all but rapid urease-positive organisms from producing enough ammonia to turn the phenol red pink.
What bacteria are urease-positive?
Urease-positive pathogens include:
- Proteus mirabilis and Proteus vulgaris.
- Ureaplasma urealyticum, a relative of Mycoplasma spp.
- Nocardia.
- Corynebacterium urealyticum.
- Cryptococcus spp., an opportunistic fungus.
- Helicobacter pylori.
What is the purpose of carbohydrate fermentation test?
The carbohydrate fermentation test is used to determine whether or not a bacteria can utilize a certain carbohydrate. It tests for the presence of acid and/or gas produced from the fermentation of a single particular carbohydrate.
What is the purpose of phenol red in the urea broth medium?
what is the purpose of the phenol red in the urea broth or slant medium? phenol red is added so that it can detect urease activity. It is a pH indicator.
What is the indicator used in urea media?
phenol red
Urea Agar is a lightly buffered medium containing urea and phenol red, a pH indicator. When organisms utilize urea, ammonia is formed which turns the medium alkaline. Phenol red changes the medium color from pale-yellow to pink-red in an alkaline environment.
What happens if H. pylori positive?
If your results were positive, it means you have an H. pylori infection. H. pylori infections are treatable.
What is a positive urea test?
Urease test is used for the presumptive evidence of the presence of Helicobacter pylori in tissue biopsy material. This is done by placing a portion of crushed tissue biopsy material directly into urease broth. A positive urease test is considered presence of Helicobacter pylori.
Is urea broth selective or differential media?
Urease broth is a differential medium that tests the ability of an organism to produce an exoenzyme, called urease, that hydrolyzes urea to ammonia and carbon dioxide. The broth contains two pH buffers, urea, a very small amount of nutrients for the bacteria, and the pH indicator phenol red.
What is the purpose of the urea hydrolysis test?
The purpose of the urea hydrolysis test is to determine if a bacterium is able to degrade urea with the enzyme urease. INTRODUCTION: Biochemical tests serve as an important resource in identifying bacteria.
What do results from a blood urea nitrogen (BUN) test mean?
The blood urea nitrogen test, which is also called a BUN or serum BUN test, measures how much of the waste product you have in your blood. If your levels are off the normal range, this could mean that either your kidneys or your liver may not be working properly. Your doctor may order a BUN test as part of a routine checkup.