高致病性猪繁殖与呼吸综合征病毒对4月龄莱芜黑猪的致病性分析  

Pathogenic Analysis of HP-PRRSV in Experimentally Infected 4-month-old Laiwu Black Pigs

作　　者：聂丽[1] 肖一红[1] 李德龙[1] 石迎[1] 刘思当[1] 

机构地区：[1]山东农业大学动物科技学院,泰安271017

出　　处：《畜牧兽医学报》2012年第7期1079-1087,共9页ACTA VETERINARIA ET ZOOTECHNICA SINICA

基　　金：泰安市科技发展计划项目经费(200115012)

摘　　要：本试验旨在探讨高致病性猪繁殖与呼吸综合征病毒(HP-PRRSV)对地方品种猪的致病特点。将HP-PRRSV经滴鼻感染4月龄健康莱芜黑猪,观察接毒后的表现,于接毒不同时期颈静脉采血,ELISA试剂盒(IDEXX)检测外周血血清抗体水平的动态变化,定期剖杀,采集相关的器官组织制备组织切片,HE染色,观察不同组织的动态病理学变化,免疫组化染色检测病原在不同组织中的分布。结果表明,攻毒后第2天便出现一定的临床症状,但持续2d后症状就基本消失,感染猪未见死亡。攻毒后5d便可检测到抗体阳性(1/7),14d抗体达峰值。攻毒后3d便可见间质性肺炎,轻微的病毒性脑炎,实质器官颗粒变性;攻毒后7d出现典型的间质性肺炎、淋巴组织坏死、各段肠管大量嗜酸性粒细胞浸润及实质器官出现空泡变性。在攻毒后2～4周内,肺一直表现典型的间质性肺炎,病毒性脑炎逐渐加重,肾上腺变性坏死,胰腺轻微的炎性细胞浸润,甲状腺轻微充血、出血,实质器官出现严重的空泡变性。PRRSV抗原阳性信号出现在淋巴组织(淋巴结、脾、扁桃体)、气管、心、肝、肺、肾、胃、十二指肠、空肠、回肠、甲状腺、肾上腺、颌下腺、子宫、大脑及小脑内;盲肠、结肠、直肠、膀胱、胰腺、输卵管及卵巢均未见到阳性信号。阳性信号主要位于感染细胞的胞质中,偶尔出现在核内。试验结果表明:HP-PRRSV人工感染4月龄莱芜黑猪具有广泛的组织嗜性,并导致广泛的组织损伤,但临床症状表现轻微,未见死亡现象,4月龄莱芜黑猪对HP-PRRSV感染具有较强的抵抗力。试验结果为进一步研究HP-PRRSV对我国地方猪与外源品种猪的致病性差异提供了一定的理论依据。The objective of this study was to study the pathogenic characteristics of highly pathogenic of porcine reproductive and respiratory syndrome virus（HP-PRRSV） on local pig breeds.Fore-month-old healthy Laiwu black pigs were inoculated nasally with HP-PRRSV.The necrops of pigs were conducted on different days post inoculation.The antibody titers of peripheral blood serum were tested by ELISA test kits（IDEXX）.Tissues were collected for preparing tissues sections.Pathological changes of different tissues were observed through HE staining.Immunohistochemistry（IHC） protocol were developed to detect distribution of HP-PRRSV antigens in tissue samples.The results showed that slight symptoms could be seen 2 days post-infection,lasting two days before disappearing and no pigs died.Antibodies can be detected 5 days post-infection（1/7）,and reached the peak 14 days post-infection.Histopathological changes showed that interstitial pneumonia,slight viral encephalitis and particles degeneration of essence organs occurred in pigs 3 days post inoculation;typical interstitial pneumonia,necrosis of the lymphoid organs,eosinophilic cells infiltration in intestines were found and parenchymal organs appeared vacuolar degeneration 7 days post inoculation.From 2 weeks to 4 weeks post inoculation,typical interstitial pneumonia were found in lung,and the viral encephalitis becoming seriously,necrosis in adrenal,inflammatory cells infiltrating in pancreas were slight,serious congestion and hemorrhage were found in thyroid and parenchymal organs appear vacuolar degeneration acutely.PRRSV antigen-positive signals could be seen in lymphoid tissue（lymph nodes,spleen,tonsils）,trachea,heart,liver,lung,kidney,stomach,duodenum,jejunum,ileum,thyroid,adrenal gland,submandibular gland,uterus,brain and cerebellum;Cecum,colon,rectum,bladder,pancreas,fallopian tubes and ovaries were not seen positive signals.Positive signals were mainly located in the cytoplasm of infected cells,occasionally in the nucleus.This experiment confirmed th

关 键 词：高致病性繁殖与呼吸综合征 莱芜黑猪 免疫组化 病理学变化 

分 类 号：S858.285.3[农业科学—临床兽医学]