ABSTRACT
The main goal of study was finding the synergism effect of amphotricin B [AMB] and rifampin [RIF] on 3 species of Aspergillus. Activities of amphotericin B in combination with rifampin were tested in buffered yeast-nitrogen base using checkerboard method. Plates were inoculated with 20 micro l spores suspensions of each organism and incubated at 30°C for 24h. For this method, the MICs were defined as the lowest antimicrobial concentration inhibiting visible fungal growth on the plates. Minimal fungicidal concentration was defined as the first tube showing no growth on the plate. The MIC of amphotericin B for 100% of isolates of A. fumigatus and A. flavus were inhibited by 4mg/lit amphotericin B. 100% of isolates of A. niger were inhibited by 8mg/lit amphotericin B. When amphotericin B was combined with rifampin, amphotericin B MICs decreased to 2, 1 and 4mg/lit in A. fumigatus, A. flavus rephrase and A. niger respectively. The results indicate that combination of amphotreicin B and rifampin was synergistic on A. fumigatus, A. flavus and A. niger