【摘要】 用Marc-145细胞从广东省3个发病猪群分离到3株病毒,经RT-PCR方法鉴定为PRRSV变异株(NSP21594～1680bp缺失)。3株分离株第1代均对Marc-145细胞适应性不强,第2代可致典型病变,第3代TCID50分别为103.67、104.20、104.75mL-1;在透射电镜下观察主要为40～70nm大小的圆形、椭圆形具有囊膜的病毒粒子;均对氯仿、酸、碱和热敏感。3株分离株NSP2基因与CH-1a、VR-2332等经典PRRSV相比均存在2个位点30个氨基酸缺失,与JXA1、HUN4、HPDEBV等变异株具有相同缺失特性且高度相似,相似性为98.1%～98.3%。ORF5基因均由200个氨基酸组成,与JX-A1、HUN4、HPDEBV等变异株高度相似,相似性为98.5%～99.0%,且第13、151位均为具有强毒特性的精氨酸(R)。本研究进一步证实在广东省内出现以NSP2缺失30个氨基酸为特征PRRSV变异株的流行,也为科学监测和综合防控该毒株感染引起的PRRS奠定了基础。更多还原

【Abstract】 Three viruses were isolated by Marc-145 cell from sick and dead pigs in three different farms of Guangdong province and were identified as variant PRRSV strains (NSP2 1 594-1 680 deletion) by RT-PCR.Those variant PRRSV strains could adapt to Marc-145 cell and cause un-severe cell pathological effects (CPEs) at the 1st generation,the CPEs could be easily observed from the 2nd generation,and the TCID50 was 103.67,104.20,104.75mL-1 respectively at the 3rd generation.The expressed virions displayed various shapes including round and ellipse forms with diameters in the range of 40-70 nm.All three isolates were susceptible to chloroform,acid,alkali and heat.The results showed that NSP2 genes of all three strains were highly homologous and had 30 amino acid deletions compared with that of CH-1a and VR-2332,which had the same deletion compared with that of JXA1,HUN4 and HPDEBV.The ORF5 genes were consist of 200 amino acids and were 98.5% to 99.0% of homology with that of JXA1、HUN4 and HPDEBV,and the site of 13 and 151 were Arginine (R) which were related to virulent strains.更多还原