Sabouraud Dextrose Agar + Chloramphenicol + Gentamicin

Fungal infections have become increasingly more common, especially in the setting of immunocompromised patients. It is imperative first that the etiologic agent be grown and isolated on culture; only after that can the organism be identified and the most proper treatment be ensured.

Sabouraud Dextrose Agar (LC-1024), the original formulation or the Emmons modification, without any antibiotic has historically been used as the standard medium for the primary isolation of fungi and is still widely used. This medium is a modification enriched with gentamicin and chloramphenicol which supports the growth of a wide range of fungi and, due to its antibiotic content, inhibits the great majority of bacterial contaminants.

Dextrose is the fermentable carbohydrate providing carbon and energy. Peptone mixture provides nitrogen, vitamins, minerals and amino acids essential for growth. Bacteriological agar is the solidifying agent. The high dextrose concentration and acidic pH make this medium selective for fungi. Chloramphenicol is an antibiotic which aids in isolating pathogenic fungi from heavily contaminated material, as it inhibits most contaminating bacteria. It is a recommended antibiotic for use with media due to its heat stability and wide bacterial spectrum. Gentamicin is an aminoglycoside antibiotic, used to treat many types of bacterial infections by inhibiting their growth.

Preparation

Suspend 65.55 grams of the medium in 1 liter of distilled water. Mix well and dissolve by heating with frequent agitation. Boil for one minute until complete dissolution. Sterilize in autoclave at 118 °C for 15 minutes. Cool to 50 °C, mix well and dispense into plates.

Instructions for use

Inoculate the sample and incubate at 20-25 °C for less than 5 days.

• Murray, P.R., E.J. Baron, J.H. Jorgensen, M.A. Pfaller, and R. H. Yolken (ed.). 2003. Manual of clinical microbiology, 8th ed. American Society for Microbiology, Washington, D.C.
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