Degree
Master of Science
Program
Microbiology and Immunology
Supervisor
Dr. David Heinrichs
2nd Supervisor
Dr. Martin McGavin
Joint Supervisor
Abstract
USA300, a strain of community-associated methicillin resistant Staphylococcus aureus (CA-MRSA), has become prevalent in the community. Colonization of human skin requires mechanisms that allow this bacterium to overcome the innate immune defenses on the skin, including secretion of antimicrobial lipids. Antimicrobial lipids inhibit S. aureus growth and induce the staphylococcal proteolytic cascade, producing aureolysin (Aur) which processes the lipase glycerol ester hydrolase (Geh). Nearly all S. aureus strains secrete Geh, yet little information exists concerning its function. Using purified Aur and Geh we confirm that aureolysin processes proGeh to Geh. We then confirmed that geh was required for lipase activity and both forms of the purified enzyme had lipase activity. Finally we showed that optimal growth in trilinolein requires Aur, and might reflect a requirement for the proGeh form of the enzyme to convert trilinolein into toxic linoleic acid, despite that fact that both unprocessed and processed Geh catalyze the hydrolysis of trilinolein.
Recommended Citation
Vijayakumaran, Vithooshan, "Characterization of Staphylococcus aureus Lipase" (2013). Electronic Thesis and Dissertation Repository. 1584.
https://ir.lib.uwo.ca/etd/1584
Included in
Bacteria Commons, Bacteriology Commons, Biology Commons, Genetics Commons, Immunology of Infectious Disease Commons, Molecular Genetics Commons, Pathogenic Microbiology Commons