DESCRIPTIONS OF MEDICAL FUNGI

Descriptions of Medical Fungi 235
Creatinine Dextrose Bromothymol Blue Thymine (CDBT) Agar
For differentiation of C. neoformans var. neoformans and C. neoformans var. grubii
(Irokanulo et al. 1994).
Solution A:
Creatinine 1 g Dextrose 0.5 g
KH 2
PO 4
1 g MgSO 4
.7H 2
O 0.5 g
Thymine 0.1 g Distilled water 980 mL
1. Dissolve ingredients in small beaker and adjust pH to 5.6
2. Store in refrigerator.
Solution B (Aqueous Bromothymol Blue):
Bromothymol Blue 0.4 g 0.01N NaOH 64 mL
Distilled water
36 mL
1. Dissolve the Bromothymol Blue in the NaOH
2. Add to the water.
To prepare medium (1 litre for plates):
SPECIALISED CULTURE MEDIA
Solution A 980 mL Solution B 20 mL
Bacto agar (BD 214010) 20 g
Autoclave to 121 O C for 15 minutes, cool to 48 O C and dispense as plates.
L-Canavanine Glycine Bromothymol Blue (CGB) Agar
For differentiation of C. neoformans and C. gattii (Kwon-Chung et al. 1982).
Solution A:
Glycine Univar 10 g KH 2
PO 4
1 g
MgSO 4
1 g Thiamine HCl 1 mg
L-canavanine sulphate 30 mg Distilled water 100 mL
1. Dissolve ingredients in small beaker and adjust pH to 5.6
2. Filter sterilise solution using 0.22 µm filter.
3. Store in refrigerator.
Solution B (Aqueous Bromothymol Blue):
Bromothymol Blue 0.4 g 0.01N NaOH 64 mL
Distilled water
36 mL
1. Dissolve the Bromothymol Blue in the NaOH
2. Add to the water.
To prepare medium (1 litre for plates):
Distilled water 880 mL Solution B 20 mL
Bacto agar (BD 214010) 20 g
1. Autoclave to 121 O C for 15 minutes, cool to 48 O C.
2. For plates add 100 mL of the filtered solution A and mix. Dispense as
plates.