Lab Practicum #2 Question Set - 3. Urease Test (Urea Hydrolysis)

Right tube

Which tube is positive in the Urease test?

Proteus mirabilis and Proteus vulgaris cause diaper rash

26. What other disease is caused by this organism? (refers to #25)

ammonia (NH3) urease

24. Urea can be hydrolyzed to carbon dioxide and ___________________ by bacteria that produce the enzyme ______________________________.

Proteus

25. Urinary tract pathogens from the genus ______________________ can be distinguished from other enteric bacteria by their rapid urease activity

ammonia, raises, orange/yellow to pink

27. Urease-positive organisms break down urea to _______________, which ________________ the pH of the medium and changes the color of the pH indicator phenol red from _______________ to _______________.

Positive - pink tube; bacteria uses urease to breakdown urea Negative - yellow/pale orange; no urease present

28. Describe a positive urease test and a negative test (include the relative pH).

increase buffer

29. In order for a urease-positive organism to turn the urea broth pink, the organism must ___________________ the pH of the medium enough to overcome the effects of the __________________, potassium phosphate.

Helicobacter pylori

30. The urease test is an important part of the identification of the organism_________________________ , that causes peptic ulcers.

secretes enzyme urease that neutralizes stomach acid so organisms can eat the muccous membrane

31. How does this organism (refers to #30) survive stomach acid?*

majority

32. A rapid urease test is performed on the ______________________ of patients with peptic ulcer symptoms.

to not obtain a false positive from reversion of peptone metabolism

33. Why is it important that urease broth contain a buffer that can resist alkalinization of the medium from peptone metabolism?*

nitrogen

34. Ammonia is used by many bacteria as a source of the element ______________________.

nucleic acids and protein

35. Bacteria use the element listed in #34, in order to make what two classes of macromolecules?*