Sabri M Y, Zamri-Saad M, Mutalib A R, Israf D A, Muniandy N
Faculty of Veterinary Medicine, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia.
Vet Microbiol. 2000 Apr 4;73(1):13-23. doi: 10.1016/s0378-1135(99)00205-9.
The outer membrane proteins (OMP) were extracted from the P. haemolytica A2, A7 and A9 to determine their potential as immunogens and their capability for cross-protection. Sixty lambs of approximately 9 months old were divided into four main groups. Animals in Group 1 were vaccinated with 2ml vaccine containing 100microg/ml of the outer membrane proteins of P. haemolytica A2. Animals in Group 2 were similarly vaccinated with the OMPs of P. haemolytica A7 while Group 3 with OMPs of P. haemolytica A9. Animals in Group 4 were unvaccinated control. During the course of the study, serum was collected to evaluate the antibody levels toward each OMP. There appeared to be good immune responses. However, high antibody levels did not necessarily result in good protection of the animals, particularly against cross-infection with P. haemolytica A9 in animals vaccinated with the OMPs of P. haemolytica A2. It seemed that the antibody responses were more specific toward the homologous challenge but generally did not cross-protect against heterologous serotype challenge. However, the OMPs of P. haemolytica A7 produced good in vivo cross-protection and excellent correlations when good antibody responses against all serotypes led to successful reductions of the extent of lung lesions following homologous and heterologous challenge exposures. Thus, the OMPs of P. haemolytica A7 was effective in protecting animals against homologous and heterologous infection by live P. haemolytica A2, A7 and A9.
从溶血巴氏杆菌A2、A7和A9中提取外膜蛋白(OMP),以确定其作为免疫原的潜力及其交叉保护能力。将60只约9月龄的羔羊分为四个主要组。第1组动物接种含100μg/ml溶血巴氏杆菌A2外膜蛋白的2ml疫苗。第2组动物同样接种溶血巴氏杆菌A7的OMP,而第3组接种溶血巴氏杆菌A9的OMP。第4组动物为未接种疫苗的对照组。在研究过程中,收集血清以评估针对每种OMP的抗体水平。似乎有良好的免疫反应。然而,高抗体水平不一定能使动物得到良好保护,特别是在用溶血巴氏杆菌A2的OMP接种的动物中,对溶血巴氏杆菌A9的交叉感染没有良好保护作用。似乎抗体反应对同源攻击更具特异性,但一般不能对异源血清型攻击提供交叉保护。然而,溶血巴氏杆菌A7的OMP在体内产生了良好的交叉保护作用,并且当针对所有血清型的良好抗体反应导致同源和异源攻击暴露后肺部病变程度成功降低时,两者之间具有极好的相关性。因此,溶血巴氏杆菌A7的OMP能有效保护动物免受活的溶血巴氏杆菌A2、A7和A9的同源和异源感染。