1. UREASE TEST

2. UREASE TEST Dr. Abdelraouf A. Elmanama BY : SHEFAA EL ASTAL
ID :
Supervisedby:
Dr. Abdelraouf A. Elmanama

3. Introduction
Urea is a waste product of protein digestion in most vertebrates is excreted in the urine. Presence of the enzyme urease ,which liberates ammonia from urea ,is a useful diagnostic test for identifying bacteria.

4. Introduction
Urea agar contains peptone,glucose ,urea, and phenol red.pH of the prepared medium is 6.8(phenol red turns yellow ) .During incubation , bacteria possessing urease will produce ammonia that raise the pH of the medium ,turning the indicator fuchsia (hot pink) at pH 8.4.

5. Urease Test
Urease, an enzyme produced by some microorganisms, attacks the nitrogen and carbon bond in amide compounds and forms the alkaline end product ammonia. 

6. Significance
The urease test is particularly helpful in identifying Proteus from other species to due to the rapid action of the enzyme by Proteus compared to other non-lactose fermenting enterics.  The pH indicator phenol red changes to a deep pink color in the present of the alkaline ammonia.

7. Proteus * gram (-ve) bacilli * (+ve) glucose fermentation
*(-ve) oxidase test
*(-ve) lactose fermentation
*(+ve) urease test

8. Proteus

9. Salmonella *Gram (-)bacilli *(+ve) glucose fermentation
*(-ve) oxidase test
*(-ve) lactose fermentation
*(-ve)urease test
*motile

10. Salmonella enteica
Salmonella infection

11. Shigella *Gram (-)bacilli *(+ve) glucose fermentation
*(-ve) oxidase test
*(-ve) lactose fermentation
*(-ve)urease test
*(-ve) motile
Shigella grow on XLD agar

13. Procedure
1-streak the slant of christensen s urea medium with the test organism .
2-incubate at 35C (or the appropriate temperature for the organism) for 24 hours to four days.

14. Result
Positive:A bright pink with proteus ,and some citrobacter species
Negative :No charge with salmonella and shigella species

15. The tube on the left is a positive reaction, the tube in the middle is a negative reaction and the tube on the right in an un-inoculated control.

16. Urease test for the differentiation of T. mentagrophytes var
Urease test for the differentiation of T. mentagrophytes var. interdigitale [+7days] from T. rubrum. [-7days]

17. Urease test
Urea Agar

18. Control and positive urease test

20. Urease Test *Strong Urease production *Uninoculated Tube
*Negative Urease production