Open Access. Powered by Scholars. Published by Universities.®

Pathogenic Microbiology Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 2 of 2

Full-Text Articles in Pathogenic Microbiology

Characterization Of Staphylococcus Aureus Lipase, Vithooshan Vijayakumaran Aug 2013

Characterization Of Staphylococcus Aureus Lipase, Vithooshan Vijayakumaran

Electronic Thesis and Dissertation Repository

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 …


Molecular And Genomic Based Insights Into The Evolution Of Enterococcus Faecium From Commensal To Hospital-Adapted Pathogen, Jessica R. Galloway-Pena May 2013

Molecular And Genomic Based Insights Into The Evolution Of Enterococcus Faecium From Commensal To Hospital-Adapted Pathogen, Jessica R. Galloway-Pena

Dissertations & Theses (Open Access)

The basis for the recent transition of Enterococcus faecium from a primarily commensal organism to one of the leading causes of hospital-acquired infections in the United States is not yet understood. To address this, the first part of my project assessed isolates from early outbreaks in the USA and South America using sequence analysis, colony hybridizations, and minimal inhibitory concentrations (MICs) which showed clinical isolates possess virulence and antibiotic resistance determinants that are less abundant or lacking in community isolates. I also revealed that the level of ampicillin resistance increased over time in clinical strains. By sequencing the pbp5 gene, …