BRILLIANT GREEN AGAR
|Cat. no. G75||Brilliant Green Agar, 15x100mm Plate, 18ml||10 plates/bag|
Hardy Diagnostics Brilliant Green Agar is recommended for the selective enrichment of Salmonella spp. other than S. typhi and S. aratyphi from clinical and non-clinical specimens.
Kristensen, et al., in 1925, first described use of Brilliant Green Agar as a primary plating medium for the isolation of Salmonella spp.(9) Kauffmann modified the formula in 1935.(10)
The current formulation incorporates phenol red as the pH indicator and brilliant green as an inhibitory agent that acts against gram-positive organisms and gram-negative bacilli. Organisms that ferment lactose and/or sucrose exhibit yellow to yellow-green colonies surrounded by a yellow-green zone. Salmonella appears as red to pink-white colonies surrounded by a red zone in the medium.
Brilliant Green Agar is not recommended for the selective isolation of Salmonella typhi.
Ingredients per liter of deionized water:*
|Pancreatic Digest of Casein||5.0gm|
|Peptic Digest of Animal Tissue||5.0gm|
Final pH 6.9 +/- 0.2 at 25ºC.
* Adjusted and/or supplemented as required to meet performance criteria.
STORAGE AND SHELF LIFE
Storage: Upon receipt store at 2-8ºC. away from direct light. Media should not be used if there are any signs of deterioration (shrinking, cracking, or discoloration), hemolysis, contamination, or if the expiration date has passed. Product is light and temperature sensitive; protect from light, excessive heat, moisture, and freezing.
Specimen Collection: Consult listed references for information on specimen collection.(1-4,6) Infectious material should be submitted directly to the laboratory without delay and protected from excessive heat and cold. If there is to be a delay in processing, the specimen should be inoculated onto an appropriate transport medium (e.g. Cary-Blair) in order to maintain viability of the organisms.
Method of use: Allow medium to warm to room temperature prior to inoculation. Inoculate medium using the four quadrant technique as to produce isolated colonies. A heavily inoculum should be used since the medium is quite inhibitory.(3) Incubate aerobically at 35ºC. for up to 48 hours.
It is recommended that other primary plating media (e.g. MacConkey Agar, SS Agar) or fluid enrichments (e.g. Tetrathionate Broth, Selenite Cystine Broth) be used in conjunction with Brilliant Green Agar to ensure recovery of gram-negative intestinal pathogens.
INTERPRETATION OF RESULTS
Typically, Salmonella spp. and other non-lactose-fermenters appear as red to pink-white colonies surrounded by brilliant red zones in the medium. Lactose-fermenting or sucrose-fermenting organisms appear as yellow to yellow-green colonies surrounded by yellow-green zones in the medium.
The recovery of many Salmonellae is greatly jeopardized if stool specimens remain unpreserved for more than three hours before processing. If there is to be a delay in processing, the specimen should be inoculated onto an appropriate transport medium in order to maintain viability of the organisms.
Colony color variations from red to pink-white may occur in colonies of Salmonella spp. Variations in color are dependent upon the length of incubation and the strain of the organism.
Other non-lactose-fermenting or slow-lactose-fermenting organisms may grow on the agar and imitate the enteric pathogens. (8)
Brilliant Green Agar is not recommended for isolation of Salmonella typhi , Salmonella paratyphi , and Shigella spp.
The color of the medium may shift during shipment. This is normal and should not affect the performance of the medium. Placing plates in refrigerated conditions (2-8°C) upon receipt overnight will result in the medium returning to its normal appearance. The medium may become discolored if exposed to light.
MATERIALS REQUIRED BUT NOT PROVIDED
Standard microbiological supplies and equipment such as loops, other culture media, swabs, applicator sticks, incinerators, and incubators, etc., as well as serological and biochemical reagents, are not provided.
|Test Organisms||Inoculation Method*||Incubation||Results|
|A||18-24hr||35°C||Aerobic||Growth; red to pink-white colonies with red zone|
|B||18-24hr||35°C||Aerobic||Partial to complete inhibition; small yellow to yellow-green colonies|
User Quality Control
Brilliant Green Agar should appear slightly opalescent, and orange- to green-brown in color.
Salmonella enterica (ATCC® 14028) colonies growing on Brilliant Green Agar (Cat. no. G75). Incubated aerobically for 24 hours at 35ºC.
Escherichia coli (ATCC® 25922) growth inhibited on Brilliant Green Agar (Cat. no. G75). Incubated aerobically for 24 hours at 35ºC.
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. Jorgensen., 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. American Society for Microbiology, Washington, D.C.
5. MacFaddin, J.F. 1985. Media for Isolation, Cultivation, Identification, Maintenance of Bacteria, Vol. I. Williams & Wilkins, Baltimore, MD.
6. Quality Assurance for Commercially Prepared Microbiological Culture Media, M22. Clinical and Laboratory Standards Institute (CLSI - formerly NCCLS), Wayne, PA.
7. Koneman, E.W., et al. Color Atlas and Textbook of Diagnostic Microbiology, J.B. Lippincott Company, Philadelphia, PA.
8. Sack, R.B., et al. 1980. Cumitech 12; American Society for Microbiology, Washington, D.C.
9. Kristensen, M., et al. 1925. Br. J. Exp. Pathol. ; 6:291.
10. Kauffmann, F. 1935. Z. Hyg. Infektionskr.; 117:26.
ATCC is a registered trademark of the American Type Culture Collection.