欧洲型PRRSV RT-PCR检测方法的建立及ORF7基因序列比较

根据PRRSV(LV株)ORF7基因设计一对引物,建立了欧洲型PRRSV的RT-PCR检测方法.通过对50份组织病料检测及其ORF7基因序列分析,结果表明,有4份组织病料扩增出欧洲型PRRSV 576bp特异性片段,阳性率为8%,其ORF7基因序列和氨基酸推导序列与欧洲型PRRSV弱毒疫苗株(AMERVAC-PRRS)的同源性分别在99.0%～99.7%和98.5%～100%之间,而与标准毒株(LV)的同源性分别在95.9%～96.6%和96.9%～97.7%之间.表明该PT-PCR体系适合组织病料中欧洲型PRRSV的直接检测,同时也证实了欧洲型PRRSV在我国的存在,并且与疫苗株之间具有较高的同源性.

Establishment of RT-PCR Method for Diagnosing European-type PRRSV and Sequencing and Analysis of the ORF7 Gene

According to the sequence of ORF7 gene of PRRSV strain(LV),a pair of primers were designed to establish the RT-PCR system for the detection of European-type PRRSV.Based on the system,fifty suspected tissue samples of post-weaning multisystemic wasting syndrome(PMWS) were detected and the 576 bp specific products were amplified from 4 samples with the positive rate of 8%.Further results of sequencing showed that the nucleotide sequence and deduced amino acid homologies between the vaccine strain(AMERVAC-PRRS) and 4 detected strains were 99.0%-99.7% and 98.5%-100.0%,respectively.However,low level of homologies of nucleotide sequence(95.9%-96.6%) and amino acid(96.9%-97.7%) were found when compared 4 detected strains with standard strain(LV).In conclusion,the RT-PCR system for detecting the European-type PRRSV from tissue samples was workable and the results indicated that European-type PRRSV also existed in China.