Identification and Characterization of Candidate Staphylococcus aureus Antigens for Inclusion in a Multivalent Bovine Mastitis Vaccine

Author

Danielle Scarbrough, Boise State UniversityFollow

Publication Date

12-2020

Date of Final Oral Examination (Defense)

10-23-2020

Type of Culminating Activity

Thesis

Degree Title

Master of Science in Biomolecular Sciences

Department

Biology

Supervisory Committee Chair

Juliette Tinker, Ph.D.

Supervisory Committee Member

Ken Cornell, Ph.D.

Supervisory Committee Member

Brad Morrison, Ph.D.

Abstract

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.

DOI

10.18122/td/1752/boisestate

Recommended Citation

Scarbrough, Danielle, "Identification and Characterization of Candidate Staphylococcus aureus Antigens for Inclusion in a Multivalent Bovine Mastitis Vaccine" (2020). Boise State University Theses and Dissertations. 1752.
10.18122/td/1752/boisestate