The MNN2 gene knockout modulates the antifungal resistance of biofilms of Candida glabrata

• Published in: Biomolecules (Basel, Switzerland) Switzerland), 2018-10, Vol.8 (4), p.130
• Main Authors: Rodrigues, Célia Fortuna, Boas, Diana Patrícia Andrade Vilas, Haynes, Ken, Henriques, Mariana
• Format: Article
• Language: English
• Subjects: Amphotericin B; antifungal; Antifungal agents; Antifungal Agents - pharmacology; beta-Glucans - metabolism; biofilm matrix; Biofilms; Biofilms - drug effects; Biomass; Candida glabrata; Candida glabrata - drug effects; Candida glabrata - growth & development; Caspofungin; Cell Wall - drug effects; Cell Wall - metabolism; Cell walls; Confocal microscopy; Drug Resistance, Fungal - drug effects; Fluconazole; Fungal Proteins - metabolism; Gene deletion; Gene Knockout Techniques; Glucans; Mannosyltransferases - metabolism; Micafungin; Microscopy; MNN2 gene; resistance; Science & Technology; Virulence
• ISSN: 2218-273X; 2218-273X
• DOI: 10.3390/biom8040130

Candida glabrata biofilms are recognized to have high resistance to antifungals. In order to understand the effect of mannans in the resistance profile of C. glabrata mature biofilms, C. glabrata mnn2 was evaluated. Biofilm cell walls were analysed by confocal laser scanning microscopy (CLSM) and their susceptibility was assessed for fluconazole, amphotericin B, caspofungin, and micafungin. Crystal violet and Alcian Blue methods were performed to quantify the biomass and the mannans concentration in the biofilm cells and matrices, respectively. The concentration of -1,3 glucans was also measured. No visible differences were detected among cell walls of the strains, but the mutant had a high biomass reduction, after a drug stress. When compared with the reference strain, it was detected a decrease in the susceptibility of the biofilm cells and an increase of -1,3 glucans in the C. glabrata mnn2. The deletion of the MNN2 gene in C. glabrata induces biofilm matrix and cell wall variabilities that increase the resistance to the antifungal drug treatments. The rise of -1,3 glucans appears to have a role in this effect. This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit and COMPETE 2020 (POCI-01-0145-FEDER-006684) and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020–Programa Operacional Regional do Norte and Célia F. Rodrigues’ [SFRH/BD/93078/2013] PhD grant.