Antimycotic susceptibility discs are used for the determination of the susceptibility of microscopic fungi to antimycotic agents in vitro. It is possible to get the information about actual susceptibility of the tested fungal isolate by a simple diffusion method after 18-24 hrs already. The results of the antimycotic antibiogram make it possible to start a rational treatment of the mycotic infection.

Prepare a suspension (degree No. 0.5 of McFarland turbidity scale) of the tested strain in saline and flood the surface of an agar plate with this suspension. After suctioning off the remaining liquid and drying the plate (about 15 min. at room temperature) put antimycotic discs on the surface of the plate using aseptic technique. Incubate 18-24 hrs at 37°C.

After incubation, observe the presence and, if necessary, the size of inhibition zones around the antifungal discs.

Polyene antibiotics in in vitro susceptible strains are characterised by the presence of a clear, sharply bordered inhibition zone, usually small in diameter (amphotericin B and pimaricin > 10 mm, nystatin > 15 mm).

The azoles (clotrimazole, miconazole, econazole, bifonazole, ketoconazole, itraconazole, fluconazole and voriconazole), 5-Fluorocytosine and Ciclopirox olamine are characterised by an inhibition zone with mostly indistinct boundaries and a noticeable increase of the tested strains within the inhibition zone even in in vitro susceptible strains.

In vitro inhibition zone diameters for susceptible strains (mm) are as follows:

5-Fluorocytosine > 10 mm, ketoconazole, econazole, miconazole > 20 mm, bifonazole, itraconazole and Ciclopirox olamine > 10 mm, fluconazole > 15 mm, voriconazole > 17 mm.

1. The recommended growth medium for mycosis fungoides cultivation is Sabouraud glucose agar (2% glucose, 1% peptone, 2.5% agar, pH 5.6).
2. Agar with the following composition can be used for azole chemotherapeutics (but not 5-Fluorocytosine!):
3. 1% Yeast extract Difco, 2% glucose, 1% sodium citrate, 0.1% sodium hydrogen phosphate, 2.5% agar, pH 6.6) or commercial medium Antimycotic sensitivity test agar from Hi-Media.