[The value of the agar dilution method as a screening test for determining the sensitivity of Candida albicans to...

The aim of this study was to evaluate the performance of agar dilution method in the determination of fluconazole susceptibility of Candida albicans strains, by using different culture media. Hundred and seven C. albicans strains which were isolated from different clinical specimens were included to this study and fluconazole susceptibilities were determined by both of the microdilution method according to NCCLS M-27A standards, and an agar dilution based method by using CHROMagar Candida and Biggy agar. For this purpose, CHROMagar Candida and Biggy agar plates containing 0 (as control plate), 8 and 16 micrograms fluconazole per mililiter were prepared and inoculated with standard amounts of 24 hours culture suspansions of C. albicans strains. The culture media were evaluated after incubation at 30 degrees C for 48 hours, and the growth of strains in the fluconazole-containing and fluconazole-free plates were compared. C. albicans strains were accepted susceptible if there were no growth or the colonies were smaller than control media, and resistant if the colonies were the same size as in the control media. As a result, 106 (99.1%) of the strains were found susceptible and one (0.9%) was found dose-dependent susceptible to fluconazole by microdilution method, whereas none of the isolates grew on 8 and 16 micrograms/ml fluconazole containing CHROMagar Candida and Biggy agar media. Therefore, the agar dilution test results of 106 strains (99.1%) were in agreement with the reference microdilution method. In conclusion, it was thought that agar dilution screening tests using two different culture media, were rapid and practical for routine use in the determination of fluconazole susceptibilities of C. albicans strains.