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Biofilm formation by Candida albicans on various prosthetic materials and its fluconazole sensitivity: A kinetic study

Mycoscience (Impact Factor: 1.29). 01/2011; 53(3). DOI: 10.1007/s10267-011-0155-y

ABSTRACT Candida albicans has the ability to colonize various materials used in prostheses. In this report, we have studied the kinetics of biofilm formation on prosthetic materials and their susceptibility to fluconazole at various stages of development. Results indicated that C. albicans efficiently adheres to and colonizes polystyrene, polyvinylchloride, silicon, and polycarbonate surfaces. Candida albicans biofilm formation was observed to be both strain- and substrate dependent. Adhesion of cells to solid substrates was found sufficient to induce fluconazole resistance. Drug susceptibility at different stages of biofilm growth showed that Candida biofilms on these substrates are highly resistant to fluconazole. The study focuses on the limitations of fluconazole to combat biofilm-related infections and emphasizes the need for better therapeutic strategies against prosthesis-associated C. albicans infections.

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    • "None of the authors of this manuscript has any financial or personal relationship with other people or organizations that could inappropriately influence their work.. prescribed drug fluconazole (Shinde et al., 2012). Additionally , biofilms may act as reservoirs of infectious cells to cause re-infections (LaFleur et al., 2006). "
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    ABSTRACT: Infections associated with the biofilms of Candida albicans are a challenge to antifungal treatment. Combinatorial therapy involving plant molecules with antifungal drugs would be an effective complementary approach against drug-resistant Candida biofilms. The aim of this study was to evaluate the efficacy of three bioactive terpenoids (carvacrol, eugenol and thymol) in combination with fluconazole against planktonic cells, biofilm development and mature biofilms of C. albicans. Activities of the selected molecules were tested using a microplate based methodology, while their combinations with fluconazole were performed in a checkerboard format. Biofilms were quantitated by XTT-metabolic assay and confirmed by microscopic observations. Combinations of carvacrol and eugenol with fluconazole were found synergistic against planktonic growth of C. albicans, while that of thymol with fluconazole did not have any interaction. Biofilm development and mature biofilms were highly resistant to fluconazole, but susceptible to three terpenoids. Sensitization of cells by sub-inhibitory concentrations of carvacrol and eugenol resulted in prevention of biofilm formation at low fluconazole concentrations, i.e. 0.032 and 0.002 mg ml􀊵1, respectively. Addition of thymol could not potentiate activity of fluconazole against biofilm formation by C. albicans. Fractional inhibitory concentration indices (FICI) for carvacrol-fluconazole and eugenol-fluconazole combinations for biofilm formation were 0.311 and 0.25, respectively. The FICI value of 1.003 indicated a status of indifference for the combination of thymol and fluconazole against biofilm formation. Eugenol and thymol combinations with fluconazole did not have useful interaction against mature biofilms of C. albicans, but the presence of 0.5 mg ml􀊵1 of carvacrol caused inhibition of mature biofilms at a significantly low concentration (i.e. 0.032 mg ml􀊵1) of fluconazole. The study indicated that carvacrol and eugenol combinations with fluconazole would be a potential alternative strategy for prevention and control of biofilm-associated C. albicans infections.
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    • "Previous works in our laboratory and by various other researchers have shown that Candida biofilms are resistant to antifungal antibiotics, including the most commonly prescribed drug, fluconazole (Ramage et al. 2005; Shinde et al. 2011). Methanolic fraction of A. calamus rhizome is reported to exhibit significant inhibition of biofilms compared to conventional antifungals (Subha and Gnanamani 2008). "
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    Phytomedicine: international journal of phytotherapy and phytopharmacology 11/2012; 20(2). DOI:10.1016/j.phymed.2012.09.029 · 2.88 Impact Factor
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    • "Biofilm growth was quantitated using XTT that is [2, 3-bis (2- methoxy-4-nitro-sulfophenyl)-2H-tetrazolium-5-carboxanilide] metabolic assay (Shinde et al., 2012). XTT solution was prepared by mixing 1 mg/ml XTT salt in PBS and stored at -20°C. "
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