238 DIFCO MANUAL 



BACTO 



SABOURAUD DEXTROSE AGAR (B109) 



DEHYDRATED 



Neopeptone, Difco 10 g. 



Bacto-Dextrose 40 g. 



Bacto-Agar 15 g. 



Bacto-Sabouraud Dextrose Agar is a modification of the Dextrose Agar 

 described by Sabouraud.^ Comparative tests have shown that Neopeptone, Difco 

 is a most satisfactory source of nitrogen for the development of fungi. It is 

 recommended for the cultivation and growth of fungi, particularly those associ- 

 ated with skin infections. 



The majority of molds are not pathogenic, but some are true parasites, pro- 

 ducing a number of common diseases such as ringworm, favus and various other 

 hair and skin lesions. Internal infections of the lung and lymphatics may also be 

 traced to molds. Bacto-Sabouraud Dextrose Agar is particularly adapted for the 

 cultivation and identification of such molds, especially those infecting the skin. 



For the primary isolation of fungi from scales and crusts, Ch'in^ suggests 

 the addition of 0.015 per cent potassium tellurite, or 0.05 per cent copper sulfate 

 to this medium in order to suppress the growth of bacteria. Emmons and Ash- 

 burn^ used a Sabouraud Dextrose Agar containing 1 per cent Neopeptone and 2 

 per cent dextrose for the isolation of Histoplasma capsulatum from rats. Emmons 

 and Hollaender* used Sabouraud Dextrose Agar prepared with Neopeptone for 

 growing Trichophyton gypseum asteroides in their studies on mutation of the 

 dermatophytes induced by ultraviolet irradiation. Robinson and Kotcher^ used 

 Sabouraud Dextrose Agar containing 20 units penicillin and 40 units dihydro- 

 streptomycin hydrochloride per ml. of medium for the isolation of Histoplasma 

 from dogs. Kotcher, Robinson and Miller^ in a study of media for the recovery 

 of H. capsulatum from tissues of artificially infected rats reported that the highest 

 percentage recovery of the organism was from spleen on Sabouraud Dextrose 

 Agar. Serowy and Jung^ used Bacto-Sabouraud Dextrose Agar in their study of 

 the Microspora and called attention to the suitability of this medium for the 

 cultivation of Microspora and other pathogenic fungi, as well as the ease with 

 which this medium may be prepared and used. 



The addition of antibiotics to acid as well as neutral media for the isolation of 

 pathogenic fungi has proven especially satisfactory. Generally 20 units penicillin 

 and 40 micrograms streptomycin or dihydrostreptomycin per ml. medium are 

 added to the sterile melted medium at 45-50 °C. under aseptic conditions. These 

 desired concentrations of penicillin may be readily obtained by dissolving the 

 contents of one (1) vial of penicillin containing 100,000 units penicillin in 10 

 ml. sterile distilled water. Two (2) ml. of this solution are added to one liter of 

 sterile melted medium at 45-50°C. under aseptic conditions (0.2 ml. per 100 ml. 

 of medium). To obtain the desired concentration of streptomycin in the same 

 medium dissolve the contents of a one gram vial of streptomycin (one million 

 micrograms) in 10 ml. sterile distilled water. One (1) ml. of this solution is 

 added to 9 ml. sterile distilled water to give a solution containing 10,000 micro- 

 grams streptomycin per ml. To each liter of medium are added 4 ml. of this 

 solution to obtain 40 micrograms per ml. (0.4 ml. for 100 ml. medium). 



To rehydrate the medium, suspend 65 grams of Bacto-Sabouraud Dextrose 

 Agar in 1000 ml. of cold distilled water and heat to boiling to dissolve the 

 medium completely. Distribute in tubes or flasks and sterilize in the autoclave for 

 15 minutes at 15 pounds pressure (121°C.) The final reaction of the medium will 

 be pH 5.6. 



