A kind of actinobacillus pleuropneumoniae recombinant toxin ApxIV albumen,It is not toxic,It can be recognized by the pig serum of different serotypes actinobacillus pleuropneumoniae infection,And height antibody response can be caused in infected pig； And can be made into a vaccine for containing recombinant toxin albumin A pxIV,The infection of actinobacillus pleuropneumoniae is resisted with what protection animal； A kind of method of assisted vaccine is separately provided,It is to mix the ApxIV recombinant toxin albumen with vaccine,Wherein vaccine can not activate bacteria vaccine for the first type of Serotyping of Actinobacilus pleuropneumoniae,Promote the immunogenicity of the vaccine,Effectively cause the immune response in animal body,It is reacted including antibody mediated and cellular immunity,Animal is protected to resist the infection of actinobacillus pleuropneumoniae,Especially use the infection of what cross protection different serotypes； Another above-mentioned recombinant toxin albumin A pxIV system can with what detecting pig whether by actinobacillus pleuropneumoniae infection diagnostic reagent.一種豬胸膜肺炎放線桿菌重組毒素ApxIV蛋白，其不具毒性，可被不同血清型豬胸膜肺炎放線桿菌感染之豬隻血清所辨識，且可在受感染豬隻中引起高度抗體反應；且可製成一含有重組毒素蛋白ApxIV之疫苗，用於保護動物抵抗豬胸膜肺炎放線桿菌之感染；另提供一種輔助疫苗的方法，其係將該ApxIV重組毒素蛋白與疫苗混合，其中疫苗可為豬胸膜肺炎放線桿菌血清型第一型不活化菌疫苗，增進該疫苗之免疫原性，有效引起動物體內之免疫反應，包括體液性及細胞性免疫反應，保護動物抵抗豬胸膜肺炎放線桿菌之感染，尤其用於交叉保護不同血清型之感染；另上述之重組毒素蛋白ApxIV係可用於偵測豬隻是否受豬胸膜肺炎放線桿菌感染之診斷試劑。
