Publication Date


Date of Final Oral Examination (Defense)


Type of Culminating Activity


Degree Title

Master of Science in Biomolecular Sciences



Major Advisor

Juliette Tinker, Ph.D.


Ken Cornell, Ph.D.


Brad Morrison, Ph.D.


Bovine mastitis, inflammation typically caused by bacterial infection, is the most prevalent disease affecting the global dairy industry. Staphylococcus aureus remains one of the most important pathogens implicated in the disease and can persist within herds at subclinical levels. A preventative S. aureus bovine mastitis vaccine would substantially lessen costs associated with treatment and restore revenue lost due to decreased milk production. One such experimental vaccine is the IsdA-CTA2/B + ClfA-CTA2/B vaccine, containing the S. aureus antigens IsdA and ClfA , each fused to the nontoxic A2/B subunits of cholera toxin, which serves as an adjuvant. Previous clinical studies have indicated protective, but not fully preventative, effects following vaccination in cows. Additional antigens are required to increase vaccine efficacy. To identify priority candidate vaccine antigens, a combined proteomics and transcriptomics approach was implemented. S. aureus was cultured in traditional LB broth and, to replicate biological conditions in the bovine udder, skim milk. S. aureus extracts were subsequently analyzed by mass spectrometry and Next Generation RNA sequencing to measure unique surface proteins and upregulated genes in skim milk culture conditions. Selected candidates were further prioritized by subcellular localization to the cell periphery and by adhesin probability. Top candidate vaccine antigens identified include: fibrinogen-binding protein (Fib), bifunctional autolysin (Atl), thermonuclease (Nuc), autolysin/adhesin (Aaa), secretory antigen SsaA-like protein, and zinc ABC transporter substrate-binding protein.