猪繁殖与呼吸综合征类NADC30与HP-PRRSV毒株RT-PCR鉴别方法的建立与应用

Establishment and application of RT-PCR methods for identifying porcine reproductive and respiratory syndrome virus(PRRSV) NADC30-like strain and HP-PRRSV strain

猪繁殖与呼吸综合征病毒(PRRSV)是一种能够引起大面积呼吸道疾病并快速传播,导致母猪流产和仔猪死亡的RNA病毒,其特性为变异快,存在毒株间的重组。因此,病原的快速检测和鉴定对于该病的防控十分重要。本试验建立了一种能够区分类高致病猪繁殖与呼吸综合征病毒类NADC30与HP-PRRSV毒株的检测方法,根据nsp2基因的高变区的比对结果,选择其保守序列,设计一对检测引物,类NADC30扩增片段大小为334 bp,HP-PRRSV毒株扩增片段大小为514 bp,通过优化反应条件,最终建立了一种一对引物就可以区分检测类NADC30与HP-PRRSV毒株的RT-PCR检测方法。应用本试验所建立的RT-PCR方法对2017年12月至2018年2月采至四川多地区的疑似PRRSV感染发病的46份肺脏进行检测。结果显示,类NADC30检出率为32. 6%,高于HP-PRRSV毒株的检出率(10. 9%)。该方法的建立,为类NADC30和HP-PRRSV毒株的快速鉴别诊断提供了方法,具有重要意义。

The porcine reproductive and respiratory syndrome virus(PRRSV)is a RNA virus that can cause a large area of respiratory diseases and spread rapidly,resulting in a large number of abortions and piglet deaths in sows.Its characteristics include rapid variation and recombination between strains.Therefore,the rapid detection and identification of pathogens is very important for the prevention and control of the disease.To establish a RT-PCR detection method for distinguishing the PRRSV NADC30-like strain from HP-PRRSV strain,the conserved sequence was selected and a pair of detection primers were designed based on the comparison of the hypervariable regions of the nsp2 gene.The amplified fragments of the NADC30-like strain and HP-PRRSV strain were 334 bp and 514 bp.By optimizing the reaction conditions,a RT-PCR detection method using a pair of primers to distinguish NADC30-like strain and the HP-PRRSV was established.Using the RT-PCR method established in this experiment,46 cases of suspected PRRSV infections collected from many areas in Sichuan from December 2017 to February 2018 were tested.The detection rate of NADC30-like was 32.6%,which was higher than that of HP-PRRSV strain(10.9%).In conclusion,these results provide a method for rapid differential diagnosis of NADC30-like and HP-PRRSV strains and have great significance.