新的高致病性PRRSV毒株FZ16A的分子特征及其致病性的研究  

Molecular and pathogenicity analyses of a new highly pathogenic porcine reproductive and respiratory syndrome virus strain FZ16A

作　　者：隋修锟[1,2] 侯绍华 林伟东[1] 张珊 贾红 郭晓宇[1] 袁维峰[1] 姜一曈[1] 鑫婷[1] 朱鸿飞[1] SUI Xiu-kun;HOU Shao-hua;LIN Wei-dong;ZHANG Shan;JIA Hong;GUO Xiao-yu;YUAN Wei-feng;JIANG Yi-tong;XIN Ting;ZHU Hong-fei(Veterinary Medicine Laboratory,Institute ofA nimal Science and Veterinary Medicine,Chinese Academy of Agricultural Sciences,Beijing 100193,China;Molecular Biology,Gemb loux A gro-Bio Tech,University of Lidge,Lid ge 4000,Belgium)

机构地区：[1]中国农业科学院北京畜牧兽医研究所兽医研究室,北京100193 [2]比利时列日大学让布鲁农学院分子生物学实验室,比利时列日4000

出　　处：《中国兽医科学》2018年第12期1511-1521,共11页Chinese Veterinary Science

基　　金：中国农业科学院科技创新工程项目(ASTIP-IAS-11)

摘　　要：为了掌握猪繁殖与呼吸综合征病毒（porcine reproductive and respiratory syndrome virus, PRRSV）分离株的遗传变异特点,从福建省某疑似猪繁殖与呼吸综合征（PRRS）发病猪场采集病料并分离病原,采用RT-PCR、间接免疫荧光试验及基因测序等方法将其鉴定为HP-PRRSV,命名为FZ16A株。对FZ16A株ORF5基因进行克隆和测序,并进行分子生物学研究。将分离毒株接种PRRSV抗原、抗体双阴性的60日龄仔猪,通过观察临床症状、病理解剖变化及其病理切片等指标初步探讨分离毒株的致病性。结果,FZ16A株是北美（NA）基因型高致病性PRRSV（HP-PRRSV）变异株。同源性分析显示,FZ16A株ORF5基因与北美株VR-2332核苷酸（氨基酸）序列的相似性为87.9%（85.1%）,与JXA1的相似性为98.8%（97%）,与欧洲典型菌株Lelystad病毒的相似性为63.3%（56.9%）。系统发育分析表明,FZ16A属于NA基因型,与其他高致病性PRRSV毒株具有相同的亚型。氨基酸序列分析表明,与VR-2332株相比,FZ16A在信号肽、跨膜区（TM）、初级中和表位（PNE）、非中性表位和N-糖基化位点方面有不同程度的变异。抗原性分析显示,FZ16A ORF5基因产物与JXA1具有相似的抗原性,抗原表位主要位于aa32-37、aa50-55、aa127-133、 aa136-142、aa147-156、aa159-171、aa174-185和aa193-198区域。致病性分析表明,该分离毒株感染猪后能引起体温升高、咳嗽、食欲下降等临床症状,但并未引起试验动物死亡。剖检结果显示,FZ16A分离株能引起试验动物肺部组织实变,淋巴结肿大。肺脏病理切片可见FZ16A感染组动物有明显的间质增生性肺炎,肺泡壁毛细血管扩张充血,肺泡壁增厚等变化。以上结果表明,本研究分离的FZ16A株是新的变异毒株,丰富了该地区的PRRSV基因数据库,并为该地区PRRSV分子流行病学研究及防控奠定了一定基础。In order to monitor the genetic variation of PRRSV.The ORF5 gene of isolate strain,which was collected from a pig farm that suspected of PRRS in Fujian Province,was cloned and sequenced by RT-PCR,gene sequencing and other methods identified as HP-PRRSV and named FZ16A strain.In order to study the pathogenicity of FZ16A,the isolate strain was inoculated to 60-days-old healthy pigs,which was negative in both of PRRSV infection and antibody.The clinical observation, gross pathology and histological evaluations of lungs were carried out to evaluate the pathogenicity of FZ16A strain.The results showed that the FZ16A strain was a variant of the highly pathogenic PRRSV（HP-PRRSV）strain of North American（NA）genotype.Homology analysis showed that the ORF5 gene of FZ16A shared 87.9%（85.1%） similarity with the VR-2332 nucleotide（amino acid）sequence of North American strain and98.8%（97%） of that of JXA1.Whereas,it only shared 63.3%（56.9%） nucleotide（amino acid） identification with the European strain Lelystad.Phylogenetic analysis showed that FZ16A belongs to the NA genotype and had the same subtype as the other highly pathogenic PRRSV strains.Amino acid sequence analysis showed that FZ16A had different degree of variation in signal peptide,transmembrane region（TM）,primary neutralizing epitope（PNE）,non-neutral epitope and N-glycosylation site compared with VR-2332 strain.Antigenicity analysis also showed that the FZ16A ORF5 gene had similar antigenicity to JXA1,with epitopes mainly located in aa32-37,aa50-55,aa127-133,aa136-142,aa147-156,aa159-171, aa174-185 and aa193-198 regions.What＇s more,FZ16A strain could cause a typical clinical syndrome of PRRSV,but could not cause mortality.Autopsy and histological examination results indicated that FZ16A could cause multifocal lesions and consolidation and interstitial pneumonia with alveolar septa thickening,and alveoli disappearance in the lung.The results of this study indicated that FZ16A strain was a new mutation strain,it may also enrich th

关 键 词：猪繁殖与呼吸综合征病毒 分离鉴定 ORF5基因 分子特征 致病性分析 

分 类 号：S852.651[农业科学—基础兽医学]