Immune efficacy of OmpH and OmpA DNA vaccines against avian Pasteurella multocida

Document Type: Full paper (Original article)

Authors

1 Department of Biological Engineering, School of Food and Biological Engineering, He Nan University of Science and Technology, Luoyang, 471003 PR, China

2 MSc in Molecular Biology, Department of Biological Engineering, School of Food and Biological Engineering, He Nan University of Science and Technology, Luoyang, 471003 PR, China

Abstract

Avian Pasteurella multocida is an agent of fowl cholera. The protective effect achieved through orthodox
vaccines is not ideal. The research on novel vaccines against avian Pasteurella multocida is imperative. In
this study, the genes encoding outer membrane protein H and A (OmpH and OmpA) were cloned into the
eukaryotic expression vector pcDNA3.1(+) and the recombinant plasmids, namely DNA vaccines (pOMPH and
pOMPA) were obtained. Five groups of chickens (n=20 per group) were intramuscularly injected with the
two recombinant plasmids, attenuated live vaccine, control vector pcDNA3.1(+) and PBS, respectively. The
immune responses and protective efficacy were evaluated after immunization by serological and challenging.
A significant increase in serum antibody levels was observed in chickens vaccinated with the attenuated live
vaccine and the two DNA vaccines. Additionally, the lymphocyte proliferation (SI values) were higher in
chickens immunized with the attenuated live vaccine and the two DNA vaccines than in those vaccinated
with pcDNA3.1(+) and PBS (P<0.05). Furthermore, the two DNA vaccines provided partial protection to the
vaccinated chickens; however, the protective efficacy was inferior to that provided by the attenuated live
vaccine.

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