高致病性猪繁殖与呼吸综合征病毒四川变异株致病性分析

发布时间：2019-03-30 21:51

【摘要】：为探究高致病性猪繁殖与呼吸综合征病毒(HP-PRRSV)四川变异株SC2012和SC2012-2人工感染仔猪的病理学特征及其在组织内的分布情况,本研究将HP-PRRSV SC2012和SC2012-2株接种健康断奶仔猪,观察不同发病阶段仔猪的临床症状;感染后第14 d剖检仔猪观察其器官病变情况、组织切片的病理学变化,通过免疫组化方法(IHC)和RT-PCR方法检测PRRSV在组织中的分布情况。结果显示,两组仔猪感染后均未出现显著的呼吸症状,并于感染后3 d~5 d出现轻微腹泻;体温测定结果显示,两组仔猪均出现轻度发热、病毒血症,但SC2012-2组较SC2012组仔猪出现时间提前、病毒滴度高、维持时间长;两组仔猪均能够通过唾液、粪便、鼻分泌物排毒;剖检仔猪肺脏均出现不同程度的间质性肺炎,肝脏表现为肝淤血,其它多个器官均有不同程度的炎性细胞浸润;临床症状和病理损伤等结果表明,SC2012较SC2012-2株毒力弱。组织内病毒分布结果显示,两株病毒均在多个器官中分布,但结合组织病理变化分析显示病毒的分布并不一定导致组织损伤,HP-PRRSV四川变异株的突变对其毒力产生了一定的影响。本研究为进一步对HP-PRRSV SC2012和SC2012-2的研究提供必需参数。
[Abstract]:To investigate the pathological characteristics and tissue distribution of highly pathogenic porcine reproductive and respiratory syndrome virus (HP-PRRSV) variant strains SC2012 and SC2012-2 in Sichuan province. In this study, HP-PRRSV SC2012 and SC2012-2 strains were inoculated into healthy weaned piglets to observe the clinical symptoms of piglets at different stages of onset. On the 14th day after infection, the pathological changes of the organs, the pathological changes of the tissue sections and the distribution of PRRSV in the tissues were observed by immunohistochemistry (IHC) and RT-PCR). The results showed that there were no significant respiratory symptoms in both groups, and mild diarrhea occurred on the 3rd and 5th day after infection. The results of thermoassay showed that the piglets of both groups had mild fever and viremia, but the time of occurrence of SC2012-2 group was earlier than that of SC2012 group, the titer of virus was higher and the maintenance time was longer, and the piglets of both groups could be excreted by saliva, feces and nasal secretions. Interstitial pneumonia was found in the lungs of all the piglets. The liver showed hepatic congestion and inflammatory cell infiltration in various other organs. The results of clinical symptoms and pathological injury showed that SC2012 was less virulent than SC2012-2 strain. The distribution of viruses in tissues showed that both strains were distributed in multiple organs, but the analysis of histopathological changes showed that the distribution of viruses did not necessarily lead to tissue damage. The mutagenesis of HP-PRRSV Sichuan variant had a certain effect on its virulence. This study provides the necessary parameters for the further study of HP-PRRSV SC2012 and SC2012-2.
【作者单位】：四川农业大学动物医学院;四川农业大学动物疫病与人类健康四川省重点实验室;
【基金】：四川省科技支撑计划项目(2014NZ0043) 教育部“长江学者与创新团队发展计划”项目(IRT13083) 四川省“十三五”育种攻关项目(2016NYZ0052) 国家“十二五”科技支撑计划(2015BAD12B04-2.3)
【分类号】：S858.28

【相似文献】