猪繁殖—呼吸综合征病毒上海分离株的病毒特性研究

对猪繁殖－呼吸综合征病毒（PRRSV）上海分离株（SH1）的理化特性和结构蛋白进行研究。结果表明，SH1分离株能致Marc-145细胞典型病变，TCID50为10^5.0mL^-1。对氯仿和乙醚、酸（pH5．5以下）、碱（pH8以上）、热（水浴56℃10min以上、37℃24h以上、28℃48h以上）均敏感。病毒负染可见以具囊膜的球形为主，囊膜上有纤突，大小为60－85nm。超薄切片可见病毒存在于细胞浆中。SH1分离株的病毒培养液经差速离心和非线性蔗糖密度梯度纯化，SDS－PAGE显示病毒结构蛋白的相对分子质量24000，19500，16000。免疫转印可见3条结构蛋白均能被PRRSV美洲株高免血清识别。

Characterization of porcine reproductive and respiratory syndrome virus isolated from Shanghai pig farm

One strain of PRRSV(SH1)was isolated from a pig farm in Shanghai by Marc-145 cells culture.The TCID50 of the isolate was 105.9 mL－1.The virus was sensitive to the treatments with chloroform,ether,buffer8.0,and water bath in 56 ℃ over 10 min,37 ℃ over 24 h,28 ℃ over 48 h.After negative staining the virions showed mostly spherical enveloped particles,in diameter 60～85 nm under electron microscopy.In thin section the virus particles had be seen in cytoplasm.Differential centrifugation and discontinuous sucrose density gradient centrifugation were adopted to concentrate and purify the SH1 from infected Marc-145 cells.The 24 000,19 500 and 16 000 major structural proteins of SH1 were shown by SDS-PAGE and recognized with the hyper-immune serum against PRRSV American strain by western-blot.