Current serological diagnostics of the zoonotic disease brucellosis, caused by the intracellular, facultative bacterial pathogen Brucella, is primarily limited to humoral antibodies against the O-side chain of the lipopolysaccharide. This limitation can result in false positives due to cross reactivity with other gram negative bacteria. Previous attempts to identify other molecular markers for diagnostic purposed haven’t resulted in sensitive and specific antigens. In the current study, we employed a new method for discovering novel Brucella proteins that induce humoral responses in cattle. We developed a phage display library that expresses 56 amino acid long Brucella peptides. Screening the library with sera from B. abortus RB51 infected cattle demonstrated that it identified antigenic peptides of Brucella. Fifty peptides demonstrated greater humoral responses at 30 days after RB51 infection as compared to sera obtained prior to vaccination. Peptides identified in the study could be beneficial as potential targets for novel Brucella diagnostics
