This study demonstrates a role for superoxide dismutases (Sods) in governing tolerance of Candida albicans biofilms to amphotericin B (AmB). Coincubation of C. albicans biofilms with AmB and the Sod inhibitors N,N'-diethyldithiocarbamate (DDC) or ammonium tetrathiomolybdate (ATM) resulted in reduced viable biofilm cells and increased intracellular reactive oxygen species levels as compared to incubation of biofilm cells with AmB, DDC, or ATM alone.
View Article and Find Full Text PDFIn this study, we demonstrated that in vitro Candida albicans biofilms grown in the presence of diclofenac showed increased susceptibility to caspofungin. These findings were further confirmed using a catheter-associated biofilm model in rats. C.
View Article and Find Full Text PDFWe investigated the molecular basis of the tolerance of Candida albicans biofilms to antifungals using the miconazole as a model compound, and translated the resulting data to other antifungals. Sessile cells of C. albicans Δefg1, lacking the transcription factor Efg1, showed increased susceptibility to miconazole, amphotericin B and caspofungin, whereas these sessile cells were equally resistant to fluconazole.
View Article and Find Full Text PDFThe antifungal plant defensin RsAFP2 isolated from radish interacts with fungal glucosylceramides and induces apoptosis in Candida albicans. To further unravel the mechanism of RsAFP2 antifungal action and tolerance mechanisms, we screened a library of 2868 heterozygous C. albicans deletion mutants and identified 30 RsAFP2-hypersensitive mutants.
View Article and Find Full Text PDFPrevious research has shown that 1% to 10% of sessile Candida albicans cells survive treatment with high doses of miconazole (a fungicidal imidazole). In the present study, we investigated the involvement of sphingolipid biosynthetic intermediates in this survival. We observed that the LCB4 gene, coding for the enzyme that catalyzes the phosphorylation of dihydrosphingosine and phytosphingosine, is important in governing the miconazole resistance of sessile Saccharomyces cerevisiae and C.
View Article and Find Full Text PDFAntimicrob Agents Chemother
September 2011
We investigated the cellular mechanisms responsible for the occurrence of miconazole-tolerant persisters in Candida albicans biofilms. Miconazole induced about 30% killing of sessile C. albicans cells at 75 μM.
View Article and Find Full Text PDFTo unravel the working mechanism of the fungicidal piperazine-1-carboxamidine derivative BAR0329, we found that its intracellular accumulation in Saccharomyces cerevisiae is dependent on functional lipid rafts. Moreover, BAR0329 induced caspase-dependent apoptosis in yeast, in which the mitochondrial fission machinery consisting of Fis1 (Whi2), Dnm1 and Mdv1 is involved. Our data are consistent with a prosurvival function of Fis1 (Whi2) and a proapoptotic function of Dnm1 and Mdv1 during BAR0329-induced yeast cell death.
View Article and Find Full Text PDFAzoles inhibit ergosterol biosynthesis, resulting in ergosterol depletion and accumulation of toxic 14alpha-methylated sterols in membranes of susceptible yeast. We demonstrated previously that miconazole induces actin cytoskeleton stabilization in Saccharomyces cerevisiae prior to induction of reactive oxygen species, pointing to an ancillary mode of action. Using a genome-wide agar-based screening, we demonstrate in this study that S.
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