Date of Award




Document Type

Master's Thesis

Degree Name

Master of Science (MS)


Department of Biological Sciences

Content Description

1 online resource (v, 26 pages) : color illustrations.

Dissertation/Thesis Chair

Cheryl Andam

Committee Members

Alex Valm, Prashanth Rangan


MRSA, MSSA, pan-genome, recombination, resistance, Staphylococcus aureus, Staphylococcus aureus infections, Drug resistance in microorganisms, Genetic recombination, Recombinant DNA

Subject Categories

Bioinformatics | Microbiology


Staphylococcus aureus is a common commensal and opportunistic pathogen of humans. It causes a variety of diseases, ranging from skin and soft infections to life-threatening invasive diseases. Many strains of S. aureus have developed resistance to a variety of antibiotic classes, including many beta-lactams. The evolution and dissemination of antibiotic resistance in S. aureus lay in large part to its remarkable ability of acquiring DNA from other organisms through horizontal gene transfer and recombination. In this study, I elucidated the relationship between frequencies of recombination events and horizontally acquired antibiotic resistant genes in a population of S. aureus sampled from bloodstream infections. Results show that methicillin-resistant strains contain more horizontally acquired antibiotic resistance genes and are also frequently recombining more often than methicillin-susceptible strains. My findings are relevant for understanding the risk of emergence of individual S. aureus strains carrying acquired resistance genes, which have been increasingly reported and cause life-threatening infections that are extremely difficult to treat.