Cross Protection Experiment in Mice Immunization with Actinobacillus pleuropneumoniae serotype 7 Genomic Expression Library

Actinobacillus (A.) pleuropneumoniae is a causative agent of porcine pleuropneumonia, which has been reported in most countries. A genomic expression library of A. pleuropneumonia serotype 7 was constructed to identify potential vaccine candidates. Plasmid DNA from the sub-libraries (L1 to L10) was used to immunize BALB/c mice. Then, 2 weeks after the final immunization, the groups of mice were challenged with A. pleuropneumonia serotype 1 (1×109 cfu). Mice immunized with one of the sublibraries (L3) had a higher level of antibodies and IFN-γ production than others. This sub-library (L3) resulted in a significant reduction in the amount of A. pleuropneumoniae recovered from mouse lungs and the survival rate of the L3 group was the most highest. Our study demonstrates that a genome expression library of A. pleuropneumoniae serotype 7 offers a novel approach for screening possible cross-serotype protection vaccine candidates against A. pleuropneumoniae serotype 1 infection.