Biofilm formation by Candida albicans on various prosthetic materials and its fluconazole sensitivity: A kinetic study
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). "
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 ml1, 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 ml1 of carvacrol caused inhibition of mature biofilms at a significantly low concentration (i.e. 0.032 mg ml1) 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.The Journal of General and Applied Microbiology 11/2014; 60(5):163-168. DOI:10.2323/jgam.60.163 · 0.60 Impact Factor
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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). "
ABSTRACT: Anti-Candida potential of Acorus calamus rhizome and its active principle, β-asarone, was evaluated against the human fungal pathogen, Candida albicans. β-Asarone exhibited promising growth inhibitory activity at 0.5mg/ml and it was fungicidal at 8mg/ml. Time dependant kill curve assay showed that MFC of β-asarone was highly toxic to C. albicans, killing 99.9% inoculum within 120min of exposure. β-Asarone caused significant inhibition of C. albicans morphogenesis and biofilm development at sub-inhibitory concentrations. Our data indicate that the growth inhibitory activity of β-asarone might be through inhibition of ergosterol biosynthesis. Hemolytic assay showed that β-asarone is non-toxic, even at concentrations approaching MIC value. Our results suggest that β-asarone may be safe as a topical antifungal agent.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. "
ABSTRACT: A wide variety of signaling molecules produced by bacteria may influence physiology of neighboring microorganisms. Indole, a small molecule secreted by bacteria is known to control growth, physiology as well as biofilm formation in various bacteria. Effects of indole on eukaryotic microorganisms are not known. The objective of this study was to analyze response of Candida albicans, commensal yeast of the humans, to indole. Minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of indole for the growth of C. albicans was studied as per CLSI guidelines. Effect of indole on morphogenesis and adhesion was analyzed by using microplate based standard methodologies. Activity of indole on biofilm development and mature biofilms was studied in an in vitro biofilm model using XTT-metabolic assay and microscopic observations. Indole exhibited fungistatic as well as fungicidal properties to inhibit planktonic and biofilm growth in two strains of C. albicans. Interestingly, the inhibitory effects were obtained at concentrations which may exist in vivo. Indole prevented serum induced filamentous growth at concentrations lower than the growth inhibitory concentration. Inhibition of growth, morphogenesis, biofilm development and mature biofilms, for the first time suggests anti- C. albicans potential of indole, which may have significant consequences in bacterial-fungal interactions in vivo.African journal of microbiology research 07/2012; 6(30):6005-6012. DOI:10.5897/AJMR12.1074 · 0.54 Impact Factor