RESUMO
Biofilm producing Candida species are known to be more resistant to immune response and antimicrobial agents which leads to treatment failure. The aim of this study was to investigate the biofilm production among Candida species that were isolated from hospitalized patients and to compare the in vitro activities of antifungal agents with biofilm production. A total of 116 Candida spp. (79 C. albicans and 37 non-albicans Candida spp.) isolated from various specimens (blood, sterile body fluids, mucosal and skin lesion samples) were included to the study. Fluconazole, itraconazole, amphotericin B and caspofungin susceptibilities of the isolates were determined by broth microdilution method according to CLSI M27-A2 standards. Biofilm production of Candida spp. was determined by microplate method, using brain heart infusion broth supplemented with 0.25% glucose as a growth medium. Biofilm formation was detected in 33 of 116 isolates (28%) and 11 of them (33%) were the strains isolated from hemocultures. Biofilm production was determined more commonly in blood isolates than the strains isolated from other samples (p < 0.05). The biofilm production rate of non-albicans Candida species (41%) was found higher than C. albicans (23%), which the difference was statistically significant (p < 0.05). Amphotericin B and caspofungin were found the most effective antifungals with the MIC90 values of 0.06 microg/ml and 0.5 microg/ml for C. albicans, and 0.5 microg/ml and 1 microg/ml for non-albicans Candida species respectively. The observed positive correlation between the biofilm production and amphotericin B MIC values were found significant (p < 0.05). In conclusion, high biofilm production rates of Candida species may explain the increase in the rate of catheter-related Candida infections.
