Lee C W, Shewen P E, Cladman W M, Conlon J A, Mellors A, Lo R Y
Department of Veterinary Microbiology and Immunology, University of Guelph, Ontario.
Can J Vet Res. 1994 Apr;58(2):93-8.
Log phase culture supernate from Pasteurella haemolytica biotype A, serotype 1 contains a proteolytic enzyme specific for O-sialoglycoproteins. Using two methods, Western immunoblotting and enzyme neutralization assay, it was demonstrated that certain bovine sera from two previous P. haemolytica A1 vaccination and challenge trials contained antibodies (Ab) (isotypes IgG1 and IgG2 on Western immunoblot) to the sialoglycoprotease (Gcp). In these trials, selected calves were vaccinated twice with either the commercial culture supernate vaccine Presponse or given phosphate-buffered saline (PBS). One trial was conducted during spring, P. haem XIX, and the other during the winter, P. haem XXI. Although there was no clear evidence for induction of anti-Gcp in response to vaccination, several calves seroconverted following intrapulmonary challenge with live P. haemolytica A1. This is the first report of anti-Gcp Ab in bovine sera. The results indicated that the Gcp is immunogenic and that the bacterium produces the enzyme in vivo. Further, animals with an anti-Gcp response had less pneumonia at necropsy, suggesting the Gcp may induce protective immunity.
溶血巴斯德氏菌生物型A1血清型1的对数期培养物上清液含有一种对O-唾液酸糖蛋白具有特异性的蛋白水解酶。采用蛋白质免疫印迹法和酶中和试验这两种方法，证明来自之前两次溶血巴斯德氏菌A1疫苗接种和攻毒试验的某些牛血清含有针对唾液酸糖蛋白酶（Gcp）的抗体（Ab）（蛋白质免疫印迹法显示为IgG1和IgG2亚型）。在这些试验中，选择的犊牛用商业培养物上清液疫苗Presponse接种两次或给予磷酸盐缓冲盐水（PBS）。一次试验在春季进行，使用溶血巴斯德氏菌XIX，另一次在冬季进行，使用溶血巴斯德氏菌XXI。尽管没有明确证据表明接种疫苗可诱导产生抗Gcp抗体，但几只犊牛在经溶血巴斯德氏菌A1活菌肺内攻毒后出现了血清转化。这是牛血清中抗Gcp抗体的首次报道。结果表明Gcp具有免疫原性，且该细菌在体内产生这种酶。此外，有抗Gcp反应的动物在尸检时肺炎较轻，提示Gcp可能诱导保护性免疫。
