CRITERION™ BAIRD-PARKER AGAR BASE
|Cat. no. C5080||CRITERION™ Baird-Parker Agar Base||126gm|
|Cat. no. C5081||CRITERION™ Baird-Parker Agar Base||500gm|
|Cat. no. C5082||CRITERION™ Baird-Parker Agar Base||2kg|
|Cat. no. C5083||CRITERION™ Baird-Parker Agar Base||10kg|
|Cat. no. C5084||CRITERION™ Baird-Parker Agar Base||50kg|
Hardy Diagnostics CRITERION™ Baird-Parker Agar Base is prepared with Egg Yolk Tellurite Enrichment for a selective medium for the detection and enumeration of coagulase-positive staphylococci from food samples.(1)
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.
Baird-Parker Medium was developed by Baird-Parker to isolate and enumerate coagulase-positive staphylococci from foods.(3) The present formulation, by Baird-Parker, is a modification from a previous formula developed by Zebovitz, Evan, and Niven.(4) Sodium pyruvate was added as a selective growth stimulant, and egg yolk emulsion as a differentiation agent. The medium allows growth of Staphylococcus aureus and selectively inhibits growth of most other bacteria.
Selective inhibition is thought to be caused by the combination of the selective agents tellurite and lithium. Glycine and pyruvate are added to enhance the growth of staphylococci.
After 24 to 48 hours of incubation at 35-37ºC., colonies of S. aureus will appear black, convex, shiny, and 1-1.5mm in diameter. The very distinct black colonies formed by S. aureus are a result of the reduction of tellurite in the medium. These colonies will normally be surrounded by clear zones, a result of proteolysis or lipolysis. Occasionally, opaque zones will form within this clear zone, a result of lipase or lecithinase activity. Other bacteria which may grow on this medium are easily distinguished from S. aureus, as they do not form black colonies.
|Baird-Parker Agar Base:|
|Gram weight per 940ml:||63.0gm|
|Pancreatic Digest of Casein||10.0gm|
|Egg Yolk Tellurite Enrichment:|
|Egg Yolk Emulsion||50.0ml/L|
|Potassium Tellurite Solution, 1%||10.0ml/L|
Final pH 7.0 +/- 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 light tan.
Store the prepared culture media at 2-8ºC.
METHOD OF PREPARATION FOR DEHYDRATED CULTURE MEDIA
1. Suspend 63.0gm of the dehydrated culture media in 940.0ml of distilled or deionized water.
2. Heat to boiling and mix to dissolve completely.
3. Sterilize in the autoclave at 121ºC. for 15 minutes.
4. Cool to 45-50ºC.
5. Aseptically add 10mL of a sterile 1% potassium tellurite solution and 50.0mL of sterile egg yolk emulsion.
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. G96.
Coagulase-negative staphylococci generally do not grow well on Baird-Parker Agar; if some growth occurs, the typical clear zones are absent. Proteus or Bacillus species may also grow but appear as brown colonies.
MATERIALS REQUIRED BUT NOT PROVIDED
Standard microbiological supplies and equipment such as autoclaves, incinerators, and incubators, etc., are not provided.
ATCC ® 25923
|A||24hr||35°C||Aerobic||Growth; black shiny colonies with clear halo|
ATCC ® 12453
|A||24hr||35°C||Aerobic||Growth; brown colonies|
ATCC ® 25922
|B||24hr||35°C||Aerobic||Partial to complete inhibition|
User Quality Control
CRITERION™ Baird-Parker Agar Base powder should appear homogeneous, free-flowing, and light tan in color. The prepared media, with supplement, should appear opaque, and light yellow in color.
1. AOAC. Association of Official Analytical Chemists, Official Methods of Analysis, AOAC, Washington, D.C.
2. Baird-Parker. 1962. J. Appl. Bact.; 25:12.
3. Jorgensen., et al. Manual of Clinical Microbiology, American Society for Microbiology, Washington, D.C.
4. Zebovitz, Evan, et al. 1955. J. Bact.; 70:686.
ATCC is a registered trademark of the American Type Culture Collection.