Monitoring polysaccharide synthesis in Candida albicans

Brown, J. A.; Catley, Brian J.

doi:10.1016/0008-6215(92)85071-7

Cited by 16 publications

(14 citation statements)

References 8 publications

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“…We evaluated the interactions between the two PEs with soluble ␤-(1,3)-glucan extracted from Saccharomyces cerevisiae yeast cell walls (32). The structures of S. cerevisiae ␤-(1,3)-glucan and C. albicans ␤-(1,3)-glucan are quite similar, and the polysaccharide is an important part of Candida drug resistance and pathogenicity, amounting to 40% of the cell wall (33). Size-fractionated ␤-glucan samples (low MW, 11 kDa; medium MW, 150 kDa; high MW, 450 kDa) were tested ( Fig.…”

Section: Resultsmentioning

confidence: 99%

Antifungal Properties of Cationic Phenylene Ethynylenes and Their Impact on β-Glucan Exposure

Pappas

Sylejmani

Graus

et al. 2016

Antimicrob Agents Chemother

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Candida species are the cause of many bloodstream infections through contamination of indwelling medical devices. These infections account for a 40% mortality rate, posing a significant risk to immunocompromised patients. Traditional treatments against Candida infections include amphotericin B and various azole treatments. Unfortunately, these treatments are associated with high toxicity, and resistant strains have become more prevalent. As a new frontier, light-activated phenylene ethynylenes have shown promising biocidal activity against Gram-positive and -negative bacterial pathogens, as well as the environmental yeast Saccharomyces cerevisiae. In this study, we monitored the viability of Candida species after treatment with a cationic conjugated polymer [poly(p-phenylene ethynylene); PPE] or oligomer ["end-only" oligo(p-phenylene ethynylene); EO-OPE] by flow cytometry in order to explore the antifungal properties of these compounds. The oligomer was found to disrupt Candida albicans yeast membrane integrity independent of light activation, while PPE is able to do so only in the presence of light, allowing for some control as to the manner in which cytotoxic effects are induced. The contrast in killing efficacy between the two compounds is likely related to their size difference and their intrinsic abilities to penetrate the fungal cell wall. Unlike EO-OPE-DABCO (where DABCO is quaternized diazabicyclo[2,2,2]octane), PPE-DABCO displayed a strong propensity to associate with soluble ␤-glucan, which is expected to inhibit its ability to access and perturb the inner cell membrane of Candida yeast. Furthermore, treatment with PPE-DABCO unmasked Candida albicans ␤-glucan and increased phagocytosis by Dectin-1-expressing HEK-293 cells. In summary, cationic phenylene ethynylenes show promising biocidal activity against pathogenic Candida yeast cells while also exhibiting immunostimulatory effects.

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Section: Resultsmentioning

confidence: 99%

Antifungal Properties of Cationic Phenylene Ethynylenes and Their Impact on β-Glucan Exposure

Pappas

Sylejmani

Graus

et al. 2016

Antimicrob Agents Chemother

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“…We used the monoclonal antibody 1E12, which recognizes all β-glucan types present in the C. albicans cell wall [7,47]. As shown in Figure 4A, the cells of the wild type strain had the expected intense and uniform labeling of the entire cell wall profile, with numerous gold particles randomly spanning cell wall layers.…”

Section: Resultsmentioning

confidence: 99%

The MP65 gene is required for cell wall integrity, adherence to epithelial cells and biofilm formation in Candida albicans

et al. 2011

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BackgroundThe MP65 gene of Candida albicans (orf19.1779) encodes a putative β-glucanase mannoprotein of 65 kDa, which plays a main role in a host-fungus relationship, morphogenesis and pathogenicity. In this study, we performed an extensive analysis of a mp65Δ mutant to assess the role of this protein in cell wall integrity, adherence to epithelial cells and biofilm formation.ResultsThe mp65Δ mutant showed a high sensitivity to a range of cell wall-perturbing and degrading agents, especially Congo red, which induced morphological changes such as swelling, clumping and formation of hyphae. The mp65Δ mutant showed an activation of two MAPKs (Mkc1p and Cek1p), a high level of expression of two stress-related genes (DDR48 and SOD5), and a modulated expression of β-glucan epitopes, but no gross changes in cell wall polysaccharide composition. Interestingly, the mp65Δ mutant displayed a marked reduction in adhesion to BEC and Caco-2 cells and severe defects in biofilm formation when compared to the wild type. All of the mentioned properties were totally or partially recovered in a revertant strain, demonstrating the specificity of gene deletion.ConclusionsWe demonstrate that the MP65 gene of Candida albicans plays a significant role in maintaining cell wall integrity, as well as in adherence to epithelia and biofilm formation, which are major virulence attributes of this fungus.

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“…(1992) utilized 1 H and 13 C NMR spectroscopy for determining the complete structure of C. albicans cell wall phosphopeptidomannans and found that it was composed of repeating units of β‐mannose. The prediction of β‐ d ‐glucans moieties in the cell wall of C. albicans was also performed by Brown 1992. Studies by Lowman et al.…”

Section: Discussionmentioning

confidence: 99%

Exopolysaccharide analysis of biofilm‐forming Candida albicans

Lal

Sharma

Pruthi

et al. 2010

Journal of Applied Microbiology

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Aim: The major objective of the study was to analyse exopolysaccharide produced by a biofilm forming‐clinical strain of Candida albicans. Methods and Results: The biofilm‐forming ability of C. albicans recovered from infected intrauterine devices (IUDs) was evaluated using XTT (2,3‐bis[2‐methoxy‐4‐nitro‐5‐sulfophenyl]‐2H‐tetrazolium‐5‐carboxanilide) reduction assay. The morphological characteristics of the biofilm were assessed using scanning electron microscopy (SEM), atomic force microscopy (AFM) and confocal laser scanning microscopy (CLSM). Biochemical characterization of the exopolysaccharide was carried out by gel permeation chromatography, gas chromatography (GC), Fourier transform infrared (FTIR) spectroscopy and nuclear magnetic resonance (NMR) spectroscopy. Microscopic studies of C. albicans biofilm revealed complex, heterogeneous three‐dimensional structure, in which yeast cells and hyphal elements were entrenched within exopolysaccharides matrix. Chromatographic analysis data indicated C. albicans exopolysaccharide (c. 300 kDa) to be made up of four major sugar units. The FTIR spectrum revealed specific absorbance of O–H, C–H, O=C=O, C=O, C–N and C–C ring stretching. 1H and 13C NMR data showed the presence of β (1→6) and β (1→3) linkages in the exopolysaccharide chain that were assigned to α‐d‐glucose and β‐d‐glucose, α‐d‐mannose, α‐l‐rhamnose and N‐acetyl glucosamine (β‐d‐GlcNAc), respectively. Conclusions: Study suggested the production of a water soluble c. 300 kDa exopolysaccharide by C. albicans made up of glucose, mannose, rhamnose and N‐acetyl glucosamine subunits. Significance and Impact of the Study: The study could assist in the development of novel therapeutics aimed at disrupting C. albicans biofilms that will translate into improved clearance of Candida‐related infections.

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Monitoring polysaccharide synthesis in Candida albicans

Cited by 16 publications

References 8 publications

Antifungal Properties of Cationic Phenylene Ethynylenes and Their Impact on β-Glucan Exposure

Antifungal Properties of Cationic Phenylene Ethynylenes and Their Impact on β-Glucan Exposure

The MP65 gene is required for cell wall integrity, adherence to epithelial cells and biofilm formation in Candida albicans

Exopolysaccharide analysis of biofilm‐forming Candida albicans

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