Susceptibility testing of voriconazole, fluconazole, itraconazole and amphotericin B against yeast isolates in a Turkish University Hospital and effect of time of reading

Voriconazole is a promising azole effective against a variety of fungi, inc luding yeasts. In this study, we tested in vitro activities of voriconazole , fluconazole, itraconazole and amphotericin B against some ATCC and refere nce strains and 250 clinical yeast isolates. We also evaluated the effect o f time of reading on MIC results. Voriconazole was the most active agent ag ainst Candida and Trichosporon isolates, including the putatively fluconazo le-resistant C. krusei (MIC90 0.25 mu g/ml) and C. glabrata (MIC90 0.5 mu g /ml). Amphotericin B MICs were scattered in a considerably narrow range in both RPMI 1640 and Antibiotic Medium 3. MICs at 24 hours and 48 hours were similar in general for all antifungals tested. The highest percentage of st rains that showed 24-hour and 48-hour MICs within +/-1-log(2) dilution was observed for amphotericin B tested in RPMI (99%), and the lowest for amphot ericin B tested in Antibiotic Medium 3 (80%). In conclusion, voriconazole i s very effective against a wide spectrum of Candida species and 24-hour rea dings could substitute 48-hour MIC evaluation. (C) 2000 Elsevier Science In c. All rights reserved.