猪繁殖与呼吸综合征病毒NADC30-like分离株致病力分析  

Pathogenicity Analysis of Porcine Reproductive and Respiratory Syndrome Virus NADC30-like Isolate

作　　者：李秀丽[1,2] 王利丽 江珊[1,2] 池晶晶 李程 张莉[1,2] LI Xiuli;WANG Lili;JIANG Shan;CHI Jingjing;LI Cheng;ZHANG Li(Tianjin Animal Science and Veterinary Research Institute,Tianjin Academy of Agricultural Sciences,Tianjin 300384,China;Tianjin Observation and Experiment Site of National Animal Health,Tianjin 300384,China)

机构地区：[1]天津市农业科学院畜牧兽医研究所,天津300384 [2]国家动物疫病天津观测实验点,天津300384

出　　处：《天津农业科学》2022年第S01期28-32,共5页Tianjin Agricultural Sciences

基　　金：天津市科技支撑重点项目(19YFZCSN00570);天津市生猪产业技术体系创新团队猪病毒病岗位项目(ITTPRS2021003);中央级公益性科研院所基本科研业务费院级统筹项目。

摘　　要：为探究天津地区猪繁殖与呼吸综合征病毒(PRRSV)毒株的流行情况,从天津市某猪场发病猪肺脏组织中分离到1株PRRSV,扩增其Nsp2基因,核苷酸序列比对结果显示该病毒属NADC30分支,与TJnh1501株同源性最高,命名为TJ18114株,并对其感染细胞能力和对猪的致病力进行了研究。结果显示:该毒株能够在Marc145细胞上稳定增殖,引起明显的细胞病变,最佳收获时间为72 h(0.1MOI接种),TCID50为106.445·mL^(-1);用2×10^(5) TCID50·头-1的剂量经肌肉注射结合鼻腔喷雾方式接种45 d杜长大三元猪,猪只感染后24 h体温升高至40℃以上,血液中病毒载量达107.3copies·mL^(-1);感染后7 d PRRSV抗体阳转率100%;感染后15 d猪只消瘦、咳喘,剖检可见间质性肺炎,显微病理观察提示弥漫性肺泡萎缩、炎性浸润;PRRSV荧光定量PCR检测发现病猪的扁桃体、肝脏、脾脏、肺脏、肾脏和淋巴结中均含有较高的病毒。研究结果有助于进一步认识天津地区PRRSV流行毒株的体外增殖规律和临床致病特点,为PRRS的深入研究和防控提供依据。To explore the prevalence of Porcine reproductive and respiratory syndrome virus(PRRSV)in Tianjin,the Nsp2 gene of a PRRSV strain which was isolated from the lungs of diseased pigs in a pig farm was amplified.The results of nucleotide sequence alignment showed that the virus belonged to the NADC30 branch of which the highest homology with the TJnh1501,and was named the TJ18114 strain.The ability to infect cells and pathogenicity to pigs of this strain had been studied.The results showed that the strain proliferated stably on Marc145 cells and caused obvious cytopathic effect.The best harvest time was 72 h(0.1MOI inoculation)when the TCID50 was 106.445·mL^(-1).45-day-old Du Chang da Sanyuan pigs had temperature increase of above 40°C after 24 hours infection with a dose of 2×10^(5) TCID50·head-1 by intramuscular injection and nasal spray,and the viral load in the blood reached at 107.3copies·mL^(-1).The conversion rate of PRRSV antibody was 100%after 7 days infection.Pigs had weight loss,coughing,wheezing and interstitial pneumonia found on autopsy after 15 days infection.Diffuse alveolar atrophy and inflammatory infiltration were observed in the lung tissue by microscopic inspection.RT-qPCR results showed that a large number of virus were found in tonsils,hearts,livers,spleens,lungs,kidneys and lymph nodes of infected pigs.This study helpes to further understand the proliferation in vitro and clinical pathogenic characteristics of PRRSV epidemic strains in Tianjin,which provides a basis for in-depth research,prevention and control of PRRS.

关 键 词：猪繁殖与呼吸综合征病毒 NADC30-like毒株 致病力 

分 类 号：S852.65[农业科学—基础兽医学]