UREASE TEST TABLETS

K650 50 tablets

K1650 28 WEE-TAB

DISCUSSION:

Several species of Enterobacteriaceae, including Proteus, Klebsiella, and some Citrobacter species,as well as some Haemophilus species, some anaerobes. and several other bacteria, fungi, and yeast species produce the enzyme urease. This enzyme hydrolyzes urea into ammonia, water and carbon dioxide.(1) Since most stool pathogens, particularly Salmonella, Shigella, and E. coli, are urease negative, it can be useful to determine an organism's urease activity. A noteable exception to this is Yersinia enterocolitica, which is urease positive. Key Urease Test tablets indicate the presence of the alkaline ammonia end product by a color change from straw color to pink or red. WEE-TAB urease is ideal for testing anaerobes since a special atmosphere does not have to be achieved.

MATERIAL SAFETY:

Each K650 tablet contains 10 mg. of urea. K1650 tablets contain less than 2 mg. of urea. This product does not contain any material known at this time to be hazardous.

MATERIALS:

K650 Urease Tablets are sold on bottles of 50 tablets only.

K1650 WEE-TABS are sold in packs of 28 ready-to-use, pre-labeled tubes. Urease test tablets require preliminary growth on certain culture media. Consult a reference manual such as the Manual of Clinical Microbiology for the appropriate media to use. The following items are required but not provided:

Test tubes (K650 only)

Loop for harvesting colonies

Distilled water, neutral pH

QUALITY CONTROL:

Key Urease tablets should be tested prior to use with organism of known reactivity. We recommend Proteus vulgaris ATCC 8427 and E. coli ATCC 25922. Discard used tests in a manner conforming with accepted laboratory procedures for biohazardous materials.

INSTRUCTIONS:

1) Add 1 Urease Test Tablet to 1 ml. of distilled water in a small test tube. For WEE-TAB Urease add 3-5 drops of water.

2) Inoculate heavily from a culture grown on a slant or plate. Kliger, Russell, or T.S.I. agar may be used without affecting the results.

3) Incubate at 37 degrees C. Proteus gives a positive test in 1-8 hours. Some Klebsiella strains produce urease in smaller amounts and may require up to 24 hours in the K650 to show a positive reaction. Any pink or red color is a positive result.

WEE-TAB reactions take as little as 15 minutes and are finished at 6 hours.

REACTIONS:

Organism Reaction % Positive

Citrobacter sp. + 78

Edwardsiella - 0

Enterobacter sp. * - 10

E. coli - 1

Hafnia - 0

Kleb. pneumoniae + 96

Morganella + 98

Proteus mirabilis + 98

Proteus vulgaris + 98

Providencia sp.* +/- 30

Salmonella sp. - 99

Shigella sp. - 0

Yersinia sp. * + 80

* Reactions vary within sp.

REFERENCES:

(1) Bailey and Scott's Diagnostic Microbiology, 8th Editions,Chapters 9 and 27.

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