COMPARISON STUDY OF BROTH MACRODILUTION AND MICRODILUTION ANTIFUNGAL SUSCEPTIBILITY TESTS FOR THE FILAMENTOUS FUNGI

An evaluation of broth dilution antifungal susceptibility tests was pe rformed by determining both the micro- and macrodilution MICs of ampho tericin B, fluconazole, ketoconazole, 5-fluorocytosine, miconazole, an d itraconazole against representative species of opportunistic hyphomy cetes (Fusarium spp. and Cladosporium [Cladophialophora] spp,) and asc omycetes (Chaetomium spp,). A total of 78 strains were tested, the maj ority of them twice and some three times on different days, Both metho ds were performed according to the recommendations of the National Com mittee for Clinical Laboratory Standards (Document M27-P), with the ex ception of the temperature of incubation, which was 25 degrees C in ou r case, A spectrophotometric method for inoculum preparation, RPMI 164 0 medium buffered with morpholinepropanesulfonic acid (pH 7.0), and an additive drug dilution procedure were used, The MICs obtained by the two methods were read after 48, 72, and 96 h of incubation for Fusariu m spp. and after 72, 96, and 120 h for the remaining isolates, The kap pa test was used to calculate the degree of agreement, Considering the three fungal groups together, a good agreement between the results of both tests was observed with almost all the drugs at the different in cubation times, There were no cases of poor agreement, The highest lev el (kappa index = 1) was observed with ketoconazole at the second-day reading, These results support the further evaluation of the broth mic rodilution test as an alternative to the reference broth macrodilution susceptibility test.