中文摘要：

将采集的广东某猪场疑似猪高热症病料处理后接种于Marc-145细胞，出现细胞聚集、固缩、脱落等特异性细胞病变。根据GenBank中猪繁殖与呼吸综合征病毒（PRRSV）的基因序列设计并合成针对NSP2、ORF3和ORF5基因的引物，扩增目的基因并测序分析。结果表明：分离毒株XH—GD株PRRRSV属于美洲型，且NSP2基因发生30个氨基酸的不连续缺失；XH—GD的NSP2、ORF3和ORF5基因与HUB1、NX06、BJsy06、VR-2332、HB—1（sh）2002、HB-2（sh）2002、CH—1a和RespPRRSMLV等毒株等位基因的核苷酸同源性分别为83．3％-98．9％、88．6％～99．2％、88．1％～99．2％，推导的氨基酸同源性分别为76．8％～98．3％、83．7％～98．8％、88．1％～99．2％；而与Lv的等位基因核苷酸同源性分别为52．9％、65．0％和64.3％，推导的氨基酸同源性分别为31．3％、57．5％和58．9％。基因系统发育树分析表明，XH—GD与NX06、BJsy06株的亲缘关系很近，与HUB1、NX06、BJsy06、VR-2332、HB-1（sh）2002、HB-2（sh）2002、CH—1a和RespPRRSMIJV亲缘关系较近，与LV毒株处于不同的分支。

英文摘要：

The samples collected from Guangdong province were inoculated to Marc-145 cell, the PRRSV specific cytopathogenic effect （CPE） was observed and the isolates named XH-GD obtained. After reverse transcription polymerase chain reaction, the amplified NSP2,0RF3 and ORF5 fragments were analyzed by sequence comparison. The results demonstrated that XH-GD belonged to the North American genotype and its NSP2 had 30 amino acids deletion. The NSP2, ORF3 and ORF5 of XH-GD shared 83.3%-98.9%, 88.6%~ 99.2% and 88.1%-99.2% of nucleotide similarity, and 76.8%-98.3%, 83.7%-98.8% and 88.1%-99.2% of deduced amino acid similarity, with that of HUB1, NX06, BJsy06, VR-2332, HB-1 （sh）2002, HB-2 （sh）2002, CH-la and RespPRRS MLV respectively; and shared only 52.9%, 65.0% and 64.3% of nucleotide similarity, and 31.3%, 57.5% and 58.9% of deduced amino acid similarity with that of LV respectively. The phylogenetic tree revealed XH-GD had closer relationship with HUB1, NX06, BJsy06, VR-2332, HB-1（sh）2002, HB-2 （sh）2002, CH-1a and RespPRRS MLV strains than that of LV strain.