Biofilm Formation by the Fungal Pathogen Candida albicans : Development, Architecture, and Drug Resistance

Abstract

Biofilms are a protected niche for microorganisms, where they are safe from antibiotic treatment and can create a source of persistent infection. Using two clinically relevant Candida albicans biofilm models formed on bioprosthetic materials, we demonstrated that biofilm formation proceeds through three distinct developmental phases. These growth phases transform adherent blastospores to well-defined cellular communities encased in a polysaccharide matrix. Fluorescence and confocal scanning laser microscopy revealed that C. albicans biofilms have a highly heterogeneous architecture composed of cellular and noncellular elements. In both models, antifungal resistance of biofilm-grown cells increased in conjunction with biofilm formation. The expression of agglutinin-like (ALS) genes, which encode a family of proteins implicated in adhesion to host surfaces, was differentially regulated between planktonic and biofilm-grown cells. The ability of C. albicans to form biofilms contrasts sharply with that of Saccharomyces cerevisiae, which adhered to bioprosthetic surfaces but failed to form a mature biofilm. The studies described here form the basis for investigations into the molecular mechanisms of Candida biofilm biology and antifungal resistance and provide the means to design novel therapies for biofilm-based infections.

Efficacy of 7‐benzyloxyindole and other halogenated indoles to inhibit Candida albicans biofilm and hyphal formation

“…Colorimetric assays are valuable for quantifying the viabilities of eukaryotic cells, and it has been suggested the XTT assay is useful to study fungal biofilm formation and drug resistance (Chandra et al ., 2001; Kuhn et al ., 2002). Findings from our XTT assay showed that metabolic activity of biofilm and planktonic C. albicans cells was not affected after 7‐benzyloxyindole treatment at 0.02 and 0.05 mM (Fig.…”

Voriconazole Is Delivered From Antifungal-Loaded Bone Cement

“…Much like bacterial infections, fungi that cause musculoskeletal infections form biofilms [1]. Fungi in biofilms are resistant to antifungals, requiring 100 to 10009 minimum inhibitory concentration [3].…”

Candidoses associées aux cathéters

“…Bien d'autres définitions ont été proposées mais les fondements restent les mêmes, à savoir une structure complexe de cellules incluses dans une matrice extracellulaire (MEC) [37] (➜). Parmi les différentes espèces de Candida impliquées dans la formation de biofilms, C. albicans est l'espèce qui a fait l'objet des études les plus nombreuses [8,9]. Elle est également l'espèce la plus fréquemment impliquée en cas de candidémie avec une fréquence qui varie, selon les régions géographiques, de 37 % en Amérique latine à 70 % en Norvège [1,10].…”

“…Cet attachement initial est très rapidement suivi du développement fongique [13]. Chandra et al [9] ont décrit le déroulement de la formation du biofilm de C. albicans en distinguant trois phases : la phase précoce, la phase intermédiaire et la phase de maturation. La phase précoce concerne les onze premières heures du dévelop-pement.…”