Susceptibility of Candida biofilms to histatin 5 and fluconazole
Nejat Düzgüneş: 0000-0001-6159-1391
Antonie van Leeuwenhoek, International Journal of General and Molecular Microbiology
Candida-associated denture stomatitis has a high rate of recurrence. Candida biofilms formed on denture acrylic are more resistant to antifungals than planktonic yeasts. Histatins, a family of basic peptides secreted by the major salivary glands in humans, especially histatin 5, possess significant antifungal properties. We examined antifungal activities of histatin 5 against planktonic or biofilm Candida albicans and Candida glabrata. Candida biofilms were developed on poly(methyl methacrylate) discs and treated with histatin 5 (0.01-100 μM) or fluconazole (1-200 μM). The metabolic activity of the biofilms was measured by the XTT reduction assay. The fungicidal activity of histatin 5 against planktonic Candida was tested by microdilution plate assay. Biofilm and planktonic C. albicans GDH18, UTR-14 and 6122/06 were highly susceptible to histatin 5, with 50% RMA (concentration of the agent causing 50% reduction in the metabolic activity; biofilm) of 4.6 ± 2.2, 6.9 ± 3.7 and 1.7 ± 1.5 μM, and IC50 (planktonic cells) of 3.0 ± 0.5, 2.6 ± 0.1 and 4.8 ± 0.5, respectively. Biofilms of C. glabrata GDH1407 and 6115/06 were less susceptible to histatin 5, with 50% RMA of 31.2 ± 4.8 and 62.5 ± 0.7 μM, respectively. Planktonic C. glabrata was insensitive to histatin 5 (IC50 > 100 μM). Biofilm-associated Candida was highly resistant to fluconazole in the range 1-200 μM; e.g. at 100 μM only ∼ 20% inhibition was observed for C. albicans, and ∼30% inhibition for C. glabrata. These results indicate that histatin 5 exhibits antifungal activity against biofilms of C. albicans and C. glabrata developed on denture acrylic. C. glabrata is significantly less sensitive to histatin 5 than C. albicans. © 2010 Springer Science+Business Media B.V.
Susceptibility of Candida biofilms to histatin 5 and fluconazole.
Antonie van Leeuwenhoek, International Journal of General and Molecular Microbiology, 97(4), 413–417.