Protective Antigens from Virulent Isolates of Fusobacterium necrophorum FN(A)

通过胰蛋白酶裂解坏死梭杆菌FN(A)型毒力菌株菌体,分别以菌体裂解物上清和沉淀作为抗原免疫家兔制备血清。利用SDS-PAGE/Western-blot技术在菌体中筛选出4种具有免疫原性的组分,通过免疫后的攻毒试验,筛选出1种具有免疫保护性的抗原。抗原分离纯化后,进行N端氨基酸序列测定、免疫试验及生物学特性研究,据试验结果可初步判定该抗原为溶血素类似物或一种新发现的抗原物质。该抗原不仅能使机体产生保护性免疫反应,而且不同菌株中此种抗原间可产生明显的交叉免疫。A virulent isolate of the bacterium FN(A) was lysed with trypsin.Supernatants and precipitates of the bacterial lysates were used to prepare anti-FN serum by immunizing rabbits.Four immunogenic components were isolated using SDS-PAGE/Western-blot.Immunized rabbits were challenged,and one protective antigen was screened.After antigen isolation and purification,the N-terminal amino acid sequence was determined and an immunological test and hemolysis test were performed.Results suggested that this antigen is either a hemolysin analogue or a new antigenic substance.The antigen was able to induce a protective immune response as well as generate a marked cross-immune reaction among different bacterial strains.国家科技部奶牛专项(2002BA518A04);; 中国农业科学院特产研究所科研基金项目(tcs-20041