Increasing of invasive procedures, use of broad-spectrum antibiotics, widespread use of immunosuppressive therapy, bone marrow suppression and factors such as neutropenia is increasing the frequency of serious fungal infections; especially of Candida. This increase was noted to candida virulence factors. Biofilm forming capacity is an important virulence factor. In our study, we aimed to determine the biofilm formation of Candida species isolated from clinical specimens, by two different methods.
Materials and Methods: In this study 216 candida isolates which were identified and stocked from several clinical specimens which have been sent to Ege University, Medical Microbiology Department, Mycology Laboratory were used between 2012-2014 years. Modified microplate and modified XTT reduction methods have been used for determining the biofilm formation and chi-square test was used for statistical evaluations.
Results: The biofilm formation rate of Candida species was found to be 19.4% (n=42) with microplate method and 22.7% (n=49) with XTT reduction method. Biofilm formation was detected in 12.5% (n=16) of Candida albicans and 29.5% (n=26) of Non Albicans Candida (NAC) species with microplate method. However by using XTT reduction method biofilm formation detected in 15.6% (n=20) of Candida albicans and in %32.9 (n=30) of NAC species. The difference between ratios was statistically relevant (chi-square=11.246; p=0.024). Biofilm formation detected most frequently in Candida tropicalis strains (13/30 and 12/30) by the two methods used.
Conclusion: On the basis of data obtained by the study, we concluded that modified XTT reduction method is identifying better the biofilm formation and Candida tropicalis strains formed more biofilm.