Fluid Sabouraud Medium is based on the formulation described by Sabouraud (1) for the cultivation of yeasts, moulds, and aciduric microorganisms, particularly useful for the fungi associated with skin infections. It is recommended for use as a sterility testing medium for moulds and lower bacteria. This mycological sterility testing medium is in accordance with USP (2) and the FDA (3) for the determination of fungistatic activity of pharmaceutical products to avoid false sterility tests. The acid reaction of the medium is inhibitory to a large number of bacteria and makes the medium particularly well suited for cultivating fungi and acidophilic microorganisms (4, 5, 6).
Casein enzymic hydrolysate and peptic digest of animal tissue provide nitrogenous and carbonaceous compounds. Dextrose is the energy source. The low pH favours fungal growth and inhibits contaminating bacteria from clinical specimens (4). Some pathogenic fungi may produce infective spores, which are easily dispersed in air, so examination should be carried out in a safety cabinet.
For isolation of fungi from potentially contaminated specimens, a selective medium should be inoculated along with the nonselective medium. Incubate at 25-30°C with increased humidity and examine at least weekly for fungal growth and should be held for 4-6 weeks before being reported as negative. Biochemical test and serological procedures confirms the findings.
Storage and Shelf-life:
Store below 30°C in tightly closed container and the prepared medium at 2 - 8°C. Use before expiry date on the label.
References:
1. Sabouraud K., 1892, Ann. Dermatol. Syphilol, 3:1061.
2. The United States Pharmacopoeia, 2006, USP29/NF24, The United States Pharmacopeial Convention. Rockville, MD
3. Food and Drug Administration, 1992, Bacteriological Analytical Manual, 7th Edition. F. D. A Washington, D. C.
4. Murray P. R., Baron E. J., Jorgensen J. H., Pfaller M. A., Yolken R. H., (Eds.), 2003, Manual of Clinical Microbiology, 8th Ed., ASM, Washington, D.C.
5. Ajello L., Georg L. K., Kaplan W. and Kaufman L., 1963, Laboratory Manual for Medical Mycology, DHEW Publication No. 994, US Govt. Printing Office, Washington, D.C.
6. Kavon Chung and Bennett, 1992, Medical Mycology, Lea and Febiger, Philadelphia, Pa.