兔出血症的研究

Studies on Rabbit Haemorrhagic Diaease

从呼和浩特市郊区分离1株兔出血症病毒,命名NM株,对其进行了病毒理化、生物学特性检测,并研究了应用SPA协同凝集试验诊断兔出血症的方法。结果表明,病毒在兔体连续传6代,均出现典型症状及病理变化,是1株毒力稳定的强毒株,病毒粒子在电镜下呈球形,直径30.3nm,无囊膜,边缘有均匀排列的齿状突起,有实芯(占40.6％)和空芯(占59.4％)2种病毒粒子。还有少量形态不一、大小不等的类似病毒的粒子。用冷酚法提取的病毒核酸,经二苯胺显色及紫外扫描,证明为DNA。病毒的蔗糖浮密度为1.192g/ml,对氯仿、乙醚及胰蛋白酶不敏感,耐酸(pH5、pH3)耐热(50℃、56℃、60min)。病毒对人的各型红细胞有高度凝集性。经氯仿、乙醚、酸(pHs、pH3),热(50℃、56℃ 60min)处理后血凝价不降或稍降,经胰蛋白酶处理后血凝价明显降低(降5个滴度)。37℃放置4h,4℃冰箱放置48h血凝价不降,4℃放置4～13d降低一个滴度,15d降2个滴度。兔体血清HI抗体滴度与保护力呈正相关,1∶40以上可以完全抵抗强毒攻击。用内蒙古生物制药厂生产的兔出血症组织灭活苗免疫兔,可以抵抗强毒的攻击。采用原代乳兔肾细胞、Vero及BHK_(21)传代细胞,培养病毒均未成功。应用SPA协同凝集试验诊断兔出血症,特异性和可靠性均好,可作为本病的1种快速诊断方法。

A strain of rabbit haemorrhagic disase virus (NM strain) was isolated in the suburbs of Huhhot city. The chemical, physical and biological characteristics of the virus were checked, A method of diagnosis of rabbit heamorrhagic disease (RHD) using SPA coorperation agglutination (SPACOAG) was studied The virus was cultured continuously for 6 generation in rabbits, each generation showed typical clinical signs and Pathogenic changes Under electron microscope, the virus had a spherical shape with 30.3nm in diameter and no envelope.There were mainly two kinds of virus particles, the solid virions (40.6％) and the empty virions (59.4％). The buoyant density was 1.192g/ml in sucrose. It was proved that the virus nuclear acid was DNA in the bianiline colour-show test and the ultraviolet scanning. The virus could resist the treatment of chloroform, ether and trypsin, and was stable at PH5.0. PH3.0.50℃ and 56℃ for one hr. It could agglutinate any ripe of human RBC with very high HA titres. The virus HA titres did not drop or slightly dropped after treatment with chloroform ether. PH5.0. PH3.0. 50℃ and 56℃, but remarkbly dropped (5titres) after treatment with trypsin. The HA titres did not fall at 37℃ in4hr and 4℃ in 48 hr, and fell by 1 titre at 4℃ in 4～13 days and 2 titres in 15 days. The HI titres of rabbit serum antibody were interrelated positively with the protection. With the titre of 1: 40 or higher, the rabbits could be protected absolutely. The cell cultures of the virus did not meet with success (milk rabbit kidney cell, Vero and BHK21). SPA-COAG could be used as a kind of rapid diagnosis method of RHD, it was specific and reliable.