Development and effect evaluation of the medium for a Pasteurella multocida vaccine with high antigenic activity based on response surface methodology

Abstract:

[Background] The fowl cholera caused by Pasteurella multocida causes great harm to the production, while the existing culture medium has the problem of low bacterial density. [Objective] To develop the medium for the preparation of a P. multocida vaccine with high antigenic activity. [Methods] Single factor experiment, Plackett-Burman design, and response surface methodology were employed to optimize the medium composition of P. multocida. Next, the immunogenicity of the bacteria in different fermentation phases was determined. Finally, the bacteria cultured in this medium were used to prepare the vaccine, the protective effect of which was evaluated by an animal challenge test. [Results] When the developed medium was used for the culture of P. multocida, the maximum viable count reached 1.84×10¹⁰ CFU/mL in 6 h, which was 2.6 times that of the control medium. The antigenic activity of the fermented product was the highest in the stationary phase. Challenge test showed that the vaccine prepared with this culture medium well resisted the infection of P. multocida. [Conclusion] We developed the medium for preparing a P. multocida vaccine with high antigenic activity, laying a foundation for vaccine production.