Current Research Program:

Virulence factors of Aspergillus fumigatus
Aspergillus fumigatus is a filamentous fungus which can cause invasive disease in immunocompromised hosts. We are interested in the mechanisms by which this filamentous fungus invades human lung tissue and disseminates within the bloodstream. We have investigated the binding of the infectious particles, the airborne conidia, to host basal lamina proteins and found that sialic acids on the conidial surface are important mediators of adhesion in vitro. Recent studies have focussed on identification of the subterminal sugars in the sialic acid-containing glycolipids and glycoproteins in the conidial cell wall. Other research has indicated that conidia can be internalized by cultured lung epithelial cells and that these conidia can germinate and survive within the lysosomal compartment.

The survival of A. fumigatus within the bloodstream indicates that this pathogen can access iron from host iron-binding proteins such as transferrin. We are currently working on the mechanisms of iron acquisition by this fungus that permit it to survive and flourish in vivo despite the limiting concentrations of free iron in serum.

Microbial community structure and the degradation of naphthenic acids
Naphthenic acids are a family of linear and cyclic carboxylic acids that are released during the extraction of bitumen from oil sands. They are acutely toxic to aquatic organisms and so are held in tailings ponds for microbial degradation. We are measuring the structure of microbial communities that are associated with the highest rates of degradation of naphthenic acids. Both physiological (Biolog, PLFA) and genetic methods (DGGE) are being used to assess community structure.

Additional Publications