Exopolysaccharide analysis of biofilm-forming Candida albicans

• Published in: Journal of applied microbiology Vol. 109; no. 1; pp. 128 - 136
• Main Authors: Lal, P, Sharma, D, Pruthi, P, Pruthi, V
• Format: Journal Article
• Language: English
• Published: Oxford, UK Oxford, UK : Blackwell Publishing Ltd 01.07.2010; Blackwell Publishing Ltd; Blackwell; Oxford University Press
• Subjects: Acetylglucosamine - chemistry; Atomic force microscopy; biofilm; Biofilms; Biofilms - growth & development; Biological and medical sciences; Candida albicans; Candida albicans - growth & development; Candida albicans - metabolism; Candida albicans - ultrastructure; Chromatography; Confocal microscopy; Drug development; exopolysaccharide; Exopolysaccharides; Fourier analysis; Fourier transform infrared; Fourier transforms; Fundamental and applied biological sciences. Psychology; Gas chromatography; Glucosamine; Glucose; Glucose - chemistry; infected intrauterine device; Infrared spectroscopy; Intrauterine devices; IUD; Liquid chromatography; Mannose; Mannose - chemistry; Microbiology; Microscopy; NMR; NMR spectroscopy; Nuclear magnetic resonance; nuclear magnetic resonance spectroscopy; Physical characteristics; Polysaccharides - biosynthesis; Polysaccharides - chemistry; Rhamnose; Rhamnose - chemistry; Scanning electron microscopy; Scanning microscopy; Spectroscopy; Spectrum analysis; Yeasts; Candida albicans; Fourier transformation; Yeast; Applied microbiology; Device; NMR spectrometry; Extracellular; nuclear magnetic resonance; Fungi; Infection; exopolysaccharide; infected intrauterine device; Biofilm; Fungi Imperfecti; Fourier transform infrared; Polysaccharide
• ISSN: 1364-5072; 1365-2672
• DOI: 10.1111/j.1365-2672.2009.04634.x

The major objective of the study was to analyse exopolysaccharide produced by a biofilm forming-clinical strain of Candida albicans. 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[rightward arrow]6) and β (1[rightward arrow]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. 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. 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.