Graduation Date

Spring 5-6-2017

Document Type

Thesis

Degree Name

Master of Science (MS)

Programs

Pathology & Microbiology

First Advisor

Paul D. Fey, Ph.D.

Abstract

Staphylococcus aureus can survive and colonize a multitude of environmental niches including the human host. S. aureus is responsible for over 11,000 deaths yearly, and many studies correlate the survival and proliferation of S. aureus to its acquisition and utilization of proline. Proline is an important amino acid as it serves as both an osmotic protectant and carbon source. It was determined that S. aureus had a severe growth defect when grown in osmotically stressed conditions without proline. Additionally, in an abscess environment, where it is hypothesized that the primary carbon sources (i.e. glucose) are depleted, S. aureus will acquire proline from the extracellular milieu as a secondary carbon source. The transport of proline occurs through three transporters, a high-affinity proline permease, PutP and two low-affinity proline transporters, OpuD and ProP. In this study, we sought to investigate the function and regulation of the three transporters. It was determined that CcpA negatively regulated the expression of the three transporters, while σB (SigB) negatively regulated the expression of putP. Finally, we found that osmotic stress upregulates the expression of opuD and proP, but downregulates putP expression.

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