CRITERION™ CETRIMIDE SELECTIVE AGAR BASE

Cat. no. C5370 CRITERION™ Cetrimide Selective Agar Base 88.6gm
Cat. no. C5371 CRITERION™ Cetrimide Selective Agar Base 500gm
Cat. no. C5372 CRITERION™ Cetrimide Selective Agar Base 2kg
Cat. no. C5373 CRITERION™ Cetrimide Selective Agar Base 10kg
Cat. no. C5374 CRITERION™ Cetrimide Selective Agar Base 50kg

INTENDED USE

Hardy Diagnostics CRITERION™ Cetrimide Selective Agar Base is recommended for the selective isolation of Pseudomonas aeruginosa.

This dehydrated culture medium is a raw material intended to be used in the making of prepared media products, which will require further processing, additional ingredients, or supplements.

SUMMARY

Cetyltrimethylammonium bromide, a quaternary ammonium, cationic detergent, is the component of Cetrimide Agar which allows for the selective isolation of Pseudomonas aeruginosa. Cetyltrimethylammonium bromide, when in contact with bacteria, causes the release of nitrogen and phosphorous from the bacterial cell. Organisms other than P. aeruginosa are unable to withstand this germicidal activity.

Cetrimide Selective Agar employs the use of 0.03% cetrimide which follows the formulation established by Sawbury and Collins.(6) Both pyocyanin and fluorescein pigment production are enhanced on Cetrimide Agar.

FORMULA

Gram weight per liter: 44.3gm/L
Pancreatic Digest of Gelatin 20.0gm
Potassium Sulfate 10.0gm
Magnesium Chloride 1.4gm
Cetyltrimethylammonium Bromide 0.3gm
Agar 12.6gm

Final pH 7.2 +/- 0.2 at 25ºC.

* Adjusted and/or supplemented as required to meet performance criteria.

STORAGE AND SHELF LIFE

Store the sealed bottle(s) containing dehydrated culture medium at 2-30ºC. Dehydrated culture medium is very hygroscopic. Keep lid tightly sealed. Protect dehydrated culture media from moisture and light. The dehydrated culture media should be discarded if it is not free-flowing or if the color has changed from its original tan.

Store the plated culture media at 2-8ºC. and tubed media at 2-30ºC.

PRECAUTIONS

METHOD OF PREPARATION FOR DEHYDRATED CULTURE MEDIA

1. Suspend 44.3gm of the dehydrated culture media in one liter of distilled or deionized water. Add 10.0ml of glycerol and stir to mix thoroughly.

2. Boil to dissolve completely. Do not overheat.

3. Sterilize in the autoclave at 121ºC. for 15 minutes.

PROCEDURE AND INTERPRETATION OF RESULTS

For information on procedures and interpretation of results, consult listed references or refer to the prepared media Instructions for Use (IFU) for Cat. no. G18.

LIMITATIONS

Recovery rates for ready-to-use suspensions of lyophilized or water-soluble quantitative microorganism dilutions requiring no preparation or pre-incubation may encounter performance issues with direct plating and growth promotion testing on selective media. Users are advised to refer to the specific manufacturer's package insert for potential limitations using these types of QC organisms.

MATERIALS REQUIRED BUT NOT PROVIDED

Standard microbiological supplies and equipment such as autoclave, incinerators, and incubators, etc., are not provided.

QUALITY CONTROL

Test Organisms Inoculation Method* Incubation Results
Time Temperature Atmosphere
Pseudomonas aeruginosa
ATCC® 27853
A 24-48hr 35°C Aerobic Growth; yellow-green to blue colonies
Pseudomonas aeruginosa**
ATCC® 9027
J 18hr 30-35°C Aerobic Growth; yellow-green to blue colonies
Escherichia coli
ATCC® 25922
B 24-48hr 35°C Aerobic Partial to complete inhibition
Escherichia coli
ATCC® 8739
B 72hr 30-35°C Aerobic Partial to complete inhibition
Staphylococcus aureus
ATCC® 25923
B 24-48hr 35°C Aerobic Partial to complete inhibition

** Tested in accordance with USP <61> and <62>.(7,8)

User Quality Control

PHYSICAL APPEARANCE

CRITERION™ Cetrimide Selective Agar Base powder should appear homogeneous, free-flowing, and tan in color. The prepared media should be opalescent, with a precipitate, and light amber in color.

REFERENCES

1. Anderson, N.L., et al. Cumitech 3B; Quality Systems in the Clinical Microbiology Laboratory, Coordinating ed., A.S. Weissfeld. American Society for Microbiology, Washington, D.C.

2. Versalovic, J., et al. Manual of Clinical Microbiology. American Society for Microbiology, Washington, D.C.

3. Tille, P., et al. Bailey and Scott's Diagnostic Microbiology, C.V. Mosby Company, St. Louis, MO.

4. Isenberg, H.D. Clinical Microbiology Procedures Handbook, Vol. I, II & III. American Society for Microbiology, Washington, D.C.

5. Koneman, E.W., et al. Color Atlas and Textbook of Diagnostic Microbiology, J.B. Lippincott Company, Philadelphia, PA.

6. J. Clin. Path.; 8:47, 1955.

7. The Official Compendia of Standards. USP General Chapter <61> Microbiological Examination of Nonsterile Products: Microbial Enumeration Tests. USP-NF. United States Pharmacopeial Convention Inc., Rockville, MD.

8. The Official Compendia of Standards. USP General Chapter <62> Microbiological Examination of Nonsterile Products: Tests for Specified Microorganisms. USP-NF. United States Pharmacopeial Convention Inc., Rockville, MD.


ATCC is a registered trademark of the American Type Culture Collection.

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