Sabouraud Dextrose Agar Medium (USP) is a medium used for isolation of fungus.
Approximate Formula:
Ingredients
|
gm./liter
|
Mycological Peptone
|
10.0
|
Glucose
|
40.00
|
Agar
|
15.00
|
Final pH 5.6±0.2 at 25℃
|
*Adjusted and/or supplemented as required to meet performance criteria.
|
Directions:
Suspend 65g of the medium in one liter of distilled or deionized water. Mix well and heat with frequent agitation and boil for one minute. Dispense and sterilize in an autoclave at 121℃(15 lbs) for 15 minutes.
Principle and Interpretation:
Sabouraud Dextrose Agar Medium is used for the cultivation of yeasts, moulds and aciduric bacteria from pharmaceutical products in accordance with U.S. Pharmacopoeia. This medium is also employed in microbial limit tests in pharmaceutical testing, food, cosmetics, and clinical specimens.
Mycological provides nitrogenous compounds. Dextrose provides an energy source. High dextrose concentration and low pH favors fungal growth and inhibits contaminating bacteria from clinical specimens. For heavily contaminated samples, the plate must be supplemented with inhibitory agents for inhibiting bacterial growth.
Appearance:
Dehydrated medium is a free-flowing yellowish powder. The prepared medium is a kind of yellowish transparent gel.
Precautions:
This medium is for laboratory use only.
Dried medium which is past shelf life, caking or color variation cannot be used.
Storage conditions and Shelf life:
Sabouraud Dextrose Agar must be stored tightly capped in the original container at 5-30°C. The dehydrated medium has a shelf life of 3 years from date of manufacturing. Prepared medium may be stored, out of direct light at 2-8°C.
Quality control:
Cultural characteristics observed after incubation at 20-25°C for 48-72 hours.
Microorganism
|
Strains Number
|
Inoculum(CFU)
|
Growth
|
Recovery
|
Remarks
|
AspergillusNiger
|
ATCC 16404
|
20-200
|
luxuriant
|
≥70%
|
Black spores, white hypha
|
Candida Albicans
|
ATCC 10231
|
20-200
|
luxuriant
|
≥70%
|
Cream colonies
|
Reference:
1.Collee J. G., Fraser A. G., Marmion B. P., Simmons A., (Eds.), Mackie and cCartney, Practical Medical Microbiology,1996, 14th Edition, Churchill Livingstone.
2.Pezzlo M., 1998, Clin. Microbiol. Rev., 1:268-280.
3.Wilkie M. E., Almond M. K., Marsh F. P., 1992, British Medical Journal 305:1137-1141.
4.Friedman M. P. et al, 1991, J. Clin. Microbiol., 29:2385-2389.
5.MurrayP., Traynor P. Hopson D., 1992, J. Clin. Microbiol., 30:1600-1601.
6.Soriano F., Ponte C., 1992, J. Clin. Microbiol., 30:3033-3034.
7.Merlino et al, 1995, Abstr. Austr. Microbiol. 16(4):17-3.