The urease test is a laboratory test used to identify some types of bacteria by detecting an enzyme, urease, which the bacteria may or may not possess. Urease is the enzyme responsible for the degradation of urea into ammonia and bicarbonate, which increases the pH of the location where it is present.
The urease test is mainly used to diagnose infection with H. pylori, which is responsible for several gastric problems, such as gastritis, esophagitis, duodenitis, ulcers and even stomach cancer. Understand better what H. Pylori is.
If infection by H. pylori, the gastroenterologist can perform the urease test during endoscopy. If positive, treatment is started quickly with the aim of preventing the disease from progressing and relieving the person’s symptoms.
How the test is done
When the urease test is performed as a laboratory routine, no preparation is necessary for the exam. However, if it is performed during endoscopy, it is important that the person follows all the exam rules, such as avoiding using antacid medications and fasting for at least 8 hours. The urease test is carried out in the laboratory through the analysis of the collected material, with the isolation of the microorganism and biochemical identification tests, including the urease test.
In the case of the urease test to detect infection by H. pylorithe test is carried out during the upper endoscopy exam, which is an exam that evaluates the health of the esophagus and stomach, without causing pain or discomfort to the patient and the result can be evaluated in a few minutes.
During the examination, a small piece of the stomach wall is removed and placed in a vial containing urea and a pH indicator. If after a few minutes the medium changes color from yellow to pink/red, the test is said to be urease positive, confirming the infection by the H. pylori. See what symptoms may indicate a yeast infection. H. pylori.
How to understand the result
The result of the urease test may be:
- Urease positive: means that the person has an infection with a bacteria that has the urease enzyme, such as H. pylori, Staphylococcus saprophyticus, Staphylococcus epidermidis, Proteus spp. e Klebsiella pneumoniae;
- Urease negative: there is no infection with bacteria that possess the enzyme. In the case of searching for H. pyloria negative result indicates that the person does not carry this bacteria.
It is important that the results are interpreted within 24 hours so that there is no chance of false-positive results, which are those where, due to the aging of the medium, the urea starts to be degraded, which can change the color.
Bibliography
- LOURENÇO, Catarina Isabel F. Laboratory diagnosis in clinical microbiology: A study in the hospital center. Master’s thesis, 2012. Universidade Nova de Lisboa.
- ANVISA. Clinical Microbiology for the Control of Healthcare-Associated Infection. 2013. Available at: <http://www.saude.mt.gov.br/upload/controle-infeccoes/pasta13/modulo5.pdf>. Accessed on 25 Jul 2019
- ANVISA. Detection and Identification of Bacteria of Medical Importance. 2004. Available at: <http://www.anvisa.gov.br/servicosaude/microbiologia/mod_5_2004.pdf>. Accessed on 25 Jul 2019
