Fluconazole susceptibility of Brazilian Candida isolates assessed by a disk diffusion method

The increasing magnitude of antifungal resistance as well as the advent of new antifungal drugs has generated a renewed interest in fungal susceptibility testing. We used a previously described disk diffusion method to evaluate the susceptibility profile of a large collection of recent clinical Candida spp. isolates against fluconazole. A total of 1,784 yeast isolates were tested, including the following species: Candida albicans (1,036), C. tropicalis (279), C. parapsilosis (202), C. glabrata (119), C. guilliermondii (90), C. krusei (32), C. lusitaniae (7), Candida spp. (14) and other yeasts (5). Susceptibility ranking to fluconazole obtained with all yeasts tested was: C. parapsilosis congruent with C. tropicalis congruent with C. guilliermondii > C. glabrata > C. krusei. The majority (94%) of all yeast isolates tested were susceptible to fluconazole. Isolates of C. glabrata and C. krusei exhibited the highest rate of DDS/resistance among all isolates tested but they represented only 9% of all yeasts routinely sent to our lab. Careful periodical surveillance is needed in order to identify any changes in the susceptibility patterns of fluconazole with the increased use of this antifungal agent in Brazilian tertiary care hospitals.