0000000000181052
AUTHOR
Piet W. J. De Groot
Identification of Candida auris and related species by multiplex PCR based on unique GPI protein‐encoding genes
Background The pathogen Candida auris is rapidly gaining clinical importance because of its resistance to antifungal treatments and its persistence in hospital environments. Early and accurate diagnosis of C. auris infections is crucial, however, the fungus has often been misidentified by commercial systems. Objectives To develop conventional and real-time PCR methods for accurate and rapid identification of C. auris and its discrimination from closely related species by exploiting the uniqueness of certain glycosylphosphatidylinositol-modified protein-encoding genes. Methods Species-specific primers for two unique putative GPI protein-encoding genes per species were designed for C. auris, …
Deletion of GLX3 in Candida albicans affects temperature tolerance, biofilm formation and virulence.
Candida albicans is a predominant cause of fungal infections in mucosal tissues as well as life-threatening bloodstream infections in immunocompromised patients. Within the human body, C. albicans is mostly embedded in biofilms, which provides increased resistance to antifungal drugs. The glyoxalase Glx3 is an abundant proteomic component of the biofilm extracellular matrix. Here, we document phenotypic studies of a glx3Δ null mutant concerning its role in biofilm formation, filamentation, antifungal drug resistance, cell wall integrity and virulence. First, consistent with its function as glyoxalase, the glx3 null mutant showed impaired growth on media containing glycerol as the carbon sou…
5 The Ascomycetous Cell Wall: From a Proteomic Perspective
Cell walls are essential organelles for fungi; they define cell shape during growth and provide osmotic integrity and protection against harmful influences in the growth environment. Fungal walls also play an important role in developing fungal infections as they form the first contact between the pathogen and the host immune system. In many ascomycetes, the cell wall consists of a polysaccharide matrix surrounded by a layer of covalently bound glycoproteins. With the complete genome sequences being available for many species, cell wall research in recent years has largely focused on identifying and elucidating the functions of cell wall proteins. In this chapter, we discuss, with a main fo…
Pga13 in Candida albicans is localized in the cell wall and influences cell surface properties, morphogenesis and virulence.
The fungal cell wall is an essential organelle required for maintaining cell integrity and also plays an important role in the primary interactions between pathogenic fungi and their hosts. PGA13 encodes a GPI protein in the human pathogen Candida albicans, which is highly up-regulated during cell wall regeneration in protoplasts. The Pga13 protein contains a unique tandem repeat, which is present five times and is characterized by conserved spacing between the four cysteine residues. Furthermore, the mature protein contains 38% serine and threonine residues, and therefore probably is a highly glycosylated cell wall protein. Consistent with this, a chimeric Pga13-V5 protein could be localiz…
Pga26 mediates filamentation and biofilm formation and is required for virulence in Candida albicans
The Candida albicans gene PGA26 encodes a small cell wall protein and is upregulated during de novo wall synthesis in protoplasts. Disruption of PGA26 caused hypersensitivity to cell wall-perturbing compounds (Calcofluor white and Congo red) and to zymolyase, which degrades the cell wall β-1,3-glucan network. However, susceptibility to caspofungin, an inhibitor of β-1,3-glucan synthesis, was decreased. In addition, pga26Δ mutants show increased susceptibility to antifungals (fluconazol, posaconazol or amphotericin B) that target the plasma membrane and have altered sensitivities to environmental (heat, osmotic and oxidative) stresses. Except for a threefold increase in β-1,6-glucan and a sl…