Molekulare Charakterisierung adhäsiver Interaktionen zwischen Candida und Staphylococcus aureus

IZKF 2-042
C. Heilmann, C. von Eiff, K. Becker
06/2004-12/2006; 01/2007-10/2007
Interaction between staphylococci and Candida yeasts can occur either directly or mediated by bidging molecules, such as the extracellular matrix and plasma proteins fibrinogen and fibronectin, as suggested by adhesion and coaggreagtion assays. To identify staphylococcal factors involved in this interaction, we used the phage display technique. Panning of the phage display library of the clinical isolate S. aureus 4074 against Candida biofilms revealed domains of the extracellular fibrinogen-binding proteins coagulase and Efb. The coagulase leads to the conversion of fibrinogen to fibrin, which may shield the Candida cells against the host immune defense. Indeed, phagocytosis assays demonstrate a reduced phagocytosis rate of Candida in the presence of coagulase. However, further analyses are necessary to elucidate the exact role of the coagulase in modulating the immune response to Candida infections, Further panning experiments affinity-selected portions of the mostly uncharacterized S. aureus surface proteins SdrE and SasA, which needs further investigations.

Staphylococcal phenotypes: Normal and small colony variant (SCV) phenotype