Three Novel Immunogenic Proteins Determined Through 2-Dimensional Electrophoresis and Mass Spectrometry with Immune Serum Confer Protection Against Challenge with Porcine Pasteurella Multocida in Mouse Models

Pasteurella multocida is an important zoonotic pathogen that causes multiple diseases in both animals and humans. Test of good immunogenic proteins is beneficial for vaccine development and disease control. In the present study, we determined four novel immunogenic proteins of P. multocida by using 2-DE MALDI-TOF MS with immune serum. These four proteins included a trimethylamine-N-oxide reductase TorA, a translation elongation factor Ts, a phosphoglyceromutase PGAM, and a peroxiredoxin PrX. Among these proteins, TorA, Prx, and PGAM were successfully expressed by using E. coli. Western-blotting assays showed that recombinant TorA, Prx, and/or PGAM displayed good reactions with infectious sera of P. multocida serogroups A, B, D and F. Immunization of either rTorA, rPrx, and/or rPGAM induced significantly high levels of antibodies as well as IFN-γ, IL-4 and IL-10 in mice (P < 0.01). Protective efficacy tests revealed that vaccination of either rTorA, rPrx, and/or rPGAM protected 60% ~ 80% of the tested mice against the challenge with P. multocida field isolate. Our results obtained from the present study suggest that these three proteins could be tested as good vaccine candidates against P. multocida infections.