Co-administration of Staphylococcus aures Fibronectin Binding Protein A N1-3 region and Lipoteichoic acid antigen mixture enhance antibody response in BALB/c mice

Staphylococcus aureus (S. aureus) is a major human pathogen that causes a wide range of superficial skin infections to the life-threatening systemic diseases. Emergence and increasing prevalence of anti-biotic resistance S. aureus strains have accelerated the need for effective vaccines. As S. aureus pathogenesis involve its surface antigens to facilitate the colonization and invasion into host, targeting these surface antigens represent a promising strategy for S. aureus vaccine development. In this study, we evaluated the efficacy of two surface antigens of S. aureus -fibronectin-binding protein A (FnBPA) and lipoteichoic acid (LTA) as vaccine candidates. We have generated a recombinant fusion protein r-FR by fusing the N-terminal region of FnBPA and rhizavidin and expressed in Escherichia coli. The recombinant protein was mixed with the biotinylated LTA to generate r-FR+LTA antigen mixture, emulsified with Freunds adjuvant as r-FR+LTA antigen mixture or r-FR alone and immunized to BALB/c mice. Mice immunized with r-FR+LTA mixture displayed a strong antibody response, strong bacterial growth inhibition in vitro and increased survival following lethal S. aureus challenge compared with mice immunized with r-FR alone. These findings suggest that incorporation of the S. aureus surface antigens like FnBPA with LTA provides improved protective efficacy and highlights the potential of a multi-antigen vaccine strategy for preventing S. aureus infections.