RAPID UREA MEDIUM
| Cat. no. Z54 | Rapid Urea Medium, 15x45mm Vial, 2ml Deep | 10 tests/kit |
INTENDED USE
Hardy Diagnostics Rapid Urea Medium is used for the rapid determination of urease activity in bacteria such as Proteus spp., Helicobacter pylori, or in yeast, (such as Cryptococcus neoformans).
SUMMARY
Urease activity can be described as the splitting of urea via hydrolysis by a urease enzyme. The end products from this reaction yield ammonium carbonate and ammonia, which are alkaline in nature. Organisms that possess this urease enzyme may be characterized by this activity in a specific, yet rapid test formulated by Goldie.(4) The test is non-toxic, and the pH change that occurs from accumulation of alkaline end products is detected by a pH indicator in the media. Helicobacter pylori is an organism that may be easily identified by this test because of its very high endogenous urease activity. This method has been used to help simplify the diagnosis of H. pylori, especially those specimens originating from duodenal and gastric ulcers, and chronic antral gastritis (type B). The urease reaction obtained from H. pylori in Rapid Urease Medium occurs more quickly than that seen by other organisms which may split urea. As a result, it is an effective presumptive test for the presence of H. pylori.
REAGENT FORMULA
Ingredients per liter of deionized water:*
| Urea | 20.0gm |
| Monosodium Phosphate | 0.7gm |
| Phenol Red | 0.1gm |
| Agar | 4.0gm |
Final pH 6.0 +/- 0.2 at 25 degrees C.
* Adjusted and/or supplemented as required to meet performance criteria.
STORAGE AND SHELF LIFE
Upon receipt store at 2-8 degrees C. away from direct light. Media should not be used if there are any signs of contamination, deterioration, (shrinking, cracking or discoloration) or if the expiration date has passed. Product is light and temperature sensitive; protect from light, excessive heat, moisture, and freezing.
The expiration date applies to the product in its intact packaging when stored as directed.
This product has the following shelf life from the date of manufacture:
| 180 Days: | Z54 | Rapid Urea Medium |
Refer to the keyword "Storage", in the Hardy Diagnostics software program HUGO™, for more information on storing culture media.
PRECAUTIONS
This product is for in vitro diagnostic use only and is to be used only by adequately trained and qualified laboratory personnel. Observe approved biohazard precautions and aseptic techniques. All laboratory specimens should be considered infectious and handled according to "standard precautions". The "Guideline for Isolation Precautions" is available from the Centers of Disease Control and Prevention at www.cdc.gov/ncidod/dhqp/gl_isolation.html.
For additional information regarding specific precautions for the prevention of the transmission of all infectious agents from laboratory instruments and materials, and for recommendations for the management of exposure to infectious disease, refer to CLSI document M29.
Sterilize all biohazard waste before disposal.
Refer to the keyword "Precautions", in the Hardy Diagnostics software program HUGO™, for more information regarding general precautions when using culture media.
Refer to the keyword "MSDS", in the Hardy Diagnostics software program HUGO™, for more information on handling potentially hazardous material.
PROCEDURE
Isolated Organism: Using a sterile wooden applicator stick or platinum loop, obtain a loopful of a 24-48 hour old isolated organism from a non-selective agar plate (such as Chocolate Agar, Cat. no. E14). Inoculate the media by stabbing. Incubate at room temperature (15-30 degrees C.) aerobically. Observe at 15-20 minutes and again at one, three, and six hours of incubation for the development of a pink-red or red-violet color. Continue incubation of negative tests for up to 20 hours. Rapid Urea Medium may be incubated at 35 degrees C. in order to obtain faster reaction times.
Biopsy Specimen: Biopsy specimens are to be placed in 0.5ml of lactated Ringers solution at pH 6.5. Transport to laboratory on wet ice. Consult appropriate references for detailed directions on specimen collection.
Grind biopsy specimens with a sterile tissue grinder, and place a portion of the ground specimen into the Rapid Urea Medium. As an alternative to this method, the biopsy may be placed directly into the Rapid Urea Medium at the time of endoscopy, if desired. Submerge the specimen in the Rapid Urea Medium. Incubate at room temperature (15-30 degrees C.) aerobically. Observe at 15-20 minutes and again at one, three, and six hours of incubation for the development of a pink-red or red-violet color. Continue incubation of negative tests for up to 20 hours. Rapid Urea Medium may be incubated at 35 degrees C. in order to obtain faster reaction times.
INTERPRETATION OF RESULTS
A positive reaction is indicated by the appearance of a pink-red to violet color. No color change is indicative of a negative reaction. A strong positive reaction may be determined within minutes of inoculation into the Rapid Urea Medium.
LIMITATIONS
It is recommended that this test be used in conjunction with other biochemical and/or serological tests for complete identification of isolated organisms.
Nichrome inoculating loops can generate an immediate false-positive result. A sterile wooden stick or a platinum loop should be used to transfer the specimen into the Rapid Urea Medium vial.
Refer to the keyword "Limitations", in the Hardy Diagnostics software program HUGO™, for more information regarding general limitations on culture media.
MATERIALS REQUIRED BUT NOT PROVIDED
Standard microbiological supplies and equipment such as loops, incinerators, incubators, forceps, etc., as well as serological and biochemical reagents, are not provided.
QUALITY CONTROL
The following organisms are routinely used for testing at Hardy Diagnostics:
| Test Organisms | Results |
| Proteus mirabilis ATCC® 12453 |
Positive; color change from the original yellow to pink-red, slower reaction time than H. pylori |
| Escherichia coli ATCC® 25922 |
Negative; no color change observed |
User Quality Control
Check for signs of contamination and deterioration. Users of commercially prepared media may be required to perform quality control testing with at least one known organism to demonstrate growth or a positive reaction; and at least one organism to demonstrate inhibition or a negative reaction (where applicable). Refer to the following keywords, in the Hardy Diagnostics software program HUGO™, for more information on QC: "Introduction to QC", "QC of Finished Product", and "The CLSI (NCCLS) Standard and Recommendations for User QC of Media". Also see listed references for more information.(1-5)
* Refer to the keyword "Inoculation Procedures", in the Hardy Diagnostics software program HUGO™, for a description of inoculation procedures.
PHYSICAL APPEARANCE
Rapid Urea Medium should appear slightly hazy, and bright yellow to yellowish-orange in color. Do not use if media appears pink-red.
Proteus mirabilis (ATCC® 12453) in Rapid Urea Medium (Cat. no. Z54). The pink-red color development was indicative of a positive urease reaction. Incubated aerobically at room temperature for one hour. A stronger reaction will be observered after longer incubation. Alternatively, incubation can be conducted at 35 deg. C. for faster reaction.
Escherichia coli (ATCC® 25922) in Rapid Urea Medium (Cat. no. Z54). No pink-red color development was indicative of a negative urease reaction. Incubated aerobically at room temperature for 20 hours.
REFERENCES
1. Murray, P.R., et al. 1995. Manual of Clinical Microbiology, 6th ed. American Society for Microbiology, Washington, D.C.
2. Forbes, B.A., et al. 1998. Bailey and Scott's Diagnostic Microbiology, 10th ed. C.V. Mosby Company, St. Louis, MO.
3. August, M.J., et al. 1990. Cumitech 3A; Quality Control and Quality Assurance Practices in Clinical Microbiology, Coordinating ed., A.S. Weissfeld. American Society for Microbiology, Washington, D.C.
4. Goldie, J., et al. 1989. Optimization of medium for rapid urease test for detection of Campylobacter pylori in gastric antral biopsies. J. Clin. Microbiol.; 27:2080-2082.
5. Pique, J.M., et al. 1989. Notes: Rapid detection of gastric Campylobacter pylori colonization by a simple biochemical test. J. Clin. Microbiol.; 27:2604-2605.
6. Isenberg, H.D. Clinical Microbiology Procedures Handbook, Vol. I & II. American Society for Microbiology, Washington, D.C.
ATCC is a registered trademark of the American Type Culture Collection.
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