Studies on Combined Vaccine of Hemolysin and Bacterin of Actinobacillus pleuropneumoniae

摘要

Swine pleuropneumonia caused by Actinobacillus pleuropneumoniae is one of the most economically important respiratory diseases in swine industry all over the world. Vaccination with whole-cell bacterins have been used for control of the disease, whereas they do not provide adequate protection and serological cross-protection. In this study, protective efficacy of A. pleuropneumoniae extracellular toxins was evaluated for the development of efficacious vaccine. In addition, lipopolysaccharide (LPS)-removing method from LPS-Apx (for Actinobacillus pleuropneumoniae RTX-toxin) complex was studied for safer vaccine, and finally a preparation method of LPS-reduced hemolysin was established. A combined vaccine comprised of hemolysins from A. pleuropneumoniae serotype 1 by this method and whole-cell bacterin of serotype 2 was prepared and evaluated cross-protective efficacy against experimental challenge exposure with A. pleuropneumoniae sero-types 1, 2 and 5. The results of these studies were summarized as follows.