Adhesins in the human pathogenic fungus Candida Glabrata: a sticky business
Year: 2017
Type: conference-paper
Abstract: The yeast Candida glabrata is, after Candida albicans, the second most frequent fungal cause of mucosal and life-threatening bloodstream infections in immunocompromised persons. One of the characteristics of C. glabrata is its high resistance to antifungal compounds making it very difficult to eradicate these infections. The cell wall is the first contact with the human host and has an important role in the host-pathogen interactions that lead to the formation of biofilms and establishment of fungal infections. The cell wall of C. glabrata consists of ß-1,3-glucan, ß-1,6-glucan, chitin and mannoproteins. Most mannoproteins in the cell wall are GPI proteins that are covalently bound to the cell wall ß-1,6-glucan. Among these proteins are putative adhesins, which are believed to play an important role in adhesion and biofilm formation. Proteomic analysis of different strains identified a core wall proteome consisting of about 20 proteins that are present in each analyzed strain under the given conditions. In addition to this core wall proteome, proteomic analysis of hyper-adherent strains under biofilm-forming conditions showed incorporation of novel adhesins that are not found in the reference strain as well as increased levels of adhesins that are found at low levels in the reference strain. The novel adhesins are ideal targets for follow-up studies. To this end, we have created deletion mutants for the adhesinencoding genes (AWP2, AWP3, AWP8, AWP12, AWP13, AWP14) and some putative negative regulatory genes (SIR2 and HST1) in three strains, CBS138 (wild type), and the hyperadhesive strains PEU382 and PEU427. In order to improve the efficiency of correct integration of the deletion cassettes, we apply the new technique of CRISPRCas9. Phenotypic studies of adhesiveness with the obtained mutants revealed that AWP2 knockout mutants show reduced adherence to polystyrene. Unexpectedly, deletion mutants of the putative negative regulators SIR2 and HST1, showed a decline in adherence to polystyrene. We are in the process of expanding our library of deletion mutants, including double and triple deletion mutants, and performing more phenotypic to elucidate the role of these proteins in biofilm formation and establishment of infections by C. glabrata.
Language: English
Subfield: Infectious Diseases
Field: Medicine
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W7200533547