Erysipelothrix rhusiopathiae is the causative agent of swine erysipelas. In this study, we identified and characterized the extracellular proteins of E. rhusiopathiae to search for novel vaccine antigens. We searched for surface-localized proteins by analyzing the genomes of two E. rhusiopathiae strains: Fujisawa and ATCC 19414. Genome analysis revealed that the ATCC 19414 strain has three putative surface-exposed choline-binding proteins (CBPs): CbpA, CbpB, and CbpC. Each CBP contains a putative choline-binding domain. Immunogold electron microscopy confirmed that CbpA and CbpB are associated with the cell surface of E. rhusiopathiae Fujisawa. Immunization with recombinant CbpB, but not with other recombinant CBPs, protected mice against lethal challenge. A phagocytosis assay revealed that antiserum against CbpB promoted opsonin-mediated phagocytosis by murine macrophages in vitro. The protective capabilities of CbpB were confirmed in pigs, suggesting that CbpB could be used as a vaccine antigen.
(Bacterial and Parasitic Disease Research Division)
References:
Shi F and Ogawa Y. et al (2013) Infect. Immun. 81:4333-4340
