CRITERION™ BACILLUS CEREUS AGAR BASE
|Cat. no. C5060||CRITERION™ Bacillus Cereus Agar Base||82gm|
|Cat. no. C5061||CRITERION™ Bacillus Cereus Agar Base||500gm|
|Cat. no. C5062||CRITERION™ Bacillus Cereus Agar Base||2kg|
|Cat. no. C5063||CRITERION™ Bacillus Cereus Agar Base||10kg|
|Cat. no. C5064||CRITERION™ Bacillus Cereus Agar Base||50kg|
Hardy Diagnostics CRITERION™ Bacillus Cereus Agar Base is a selective agar medium used for the isolation and determination of Bacillus cereus .
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.
Holbrook and Anderson described a highly selective and diagnostic medium (PEMBA) for the isolation and determination of Bacillus cereus from food. (1) The medium is formulated to detect small numbers of contaminates. Colonies of B. cereus growing on this medium can readily be identified by microscopic examination. The addition of sodium pyruvate enhances egg yolk precipitation and sporulation. Mannitol-fermentation is detected by the pH indicator bromothymol blue. Selective activity is produced by the addition of polymyxin B at a concentration of 100,000 units per liter. (2,3) In the event of high mold content, cycloheximide (40mg/L) can be added.
|Gram weight per liter:||41.0gm/L|
|Peptic Digest of Animal Tissue||1.0gm|
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 off-white.
Store the prepared culture media at 2-8ºC.
METHOD OF PREPARATION FOR DEHYDRATED CULTURE MEDIA
1. Suspend 41.0gm of the dehydrated culture media in 950ml of distilled or deionized water.
2. Heat to boiling and mix to dissolve completely.
3. Distribute and sterilize in the autoclave at 121ºC. for 15 minutes.
4. Cool to 45-50ºC. and aseptically add enrichments (50ml of a sterile egg yolk suspension and 2ml of a filtered solution of polymyxin B (100,000units). If required, cycloheximide may be added at a concentration of 40mg/L.
5. Mix thoroughly and dispense.
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. G156.
On this medium, B. cereus is indistinguishable from B. thuringiensis .
Occasional strains of B. cereus shows weak or negative egg yolk reactions.
MATERIALS REQUIRED BUT NOT PROVIDED
Standard microbiological supplies and equipment such as autoclaves, incinerators, and incubators, etc., are not provided.
|Test Organisms||Inoculation Method*||Incubation||Results|
ATCC ® 13061
|A||24-48hr||35°C||Aerobic||Growth; blue colonies with blue precipitate halos|
ATCC ® 6633
|B||24-48hr||35°C||Aerobic||Partial to complete inhibition; media remains yellow|
ATCC ® 27853
User Quality Control
CRITERION™ Bacillus Cereus Agar Base powder should appear homogeneous, free-flowing, and off-white in color. The prepared media should appear clear to a trace hazy, and blue in color.
1. Can. 1980. J. Microbiol.; 26:753-7590.
2. Donovan, K.O. 1958. J. Appl. Bacteriol.; 21(1):100-103.
3. Mossel, D.A.A., et al. 1967. J. Appl. Bacteriol.; 15(3):650-653.
4. Vanderzant, C. and D.F. Splittstoesser, (ed.). Compendium of Methods for the Microbiological Examination of Foods, APHA, Washington, D.C.
ATCC is a registered trademark of the American Type Culture Collection.