不同毒力猪繁殖与呼吸综合征病毒对仔猪肺和外周免疫器官损伤的研究

为研究不同毒力的PRRSV对仔猪肺脏和外周免疫器官损伤的差异,本实验分别采用PRRSV变异株(HuN4株)和PRRSV经典株(CH-1a株)感染35日龄健康的断奶仔猪,并在感染后0 d、3 d、7 d、10 d和14 d各迫杀3头,检测肺、颌下淋巴结、肠系淋巴结、腹股沟淋巴结、扁桃体和脾脏的病毒载量及病理变化情况,同时检测血清中抗PRRSV的抗体水平。结果表明:感染后3 d肺脏及各免疫器官可检测到病毒,HuN4感染组病毒载量比CH-1a感染组病毒载量高1 000倍;HuN4感染组病毒载量峰值出现在感染后10 d,而CH-1a感染组维持着较低水平的病毒载量。组织病理学检测显示HuN4感染组淋巴结内淋巴细胞显著减少,呈空泡状;CH-1a感染组淋巴结内淋巴细胞轻度减少,呈星隙状。本实验表明HuN4株比CH-1a株对肺和外周免疫器官造成更严重的损伤。

Lesions in lung and peripheral immune organs of piglets infected with different virulence PRRSV strains

To evaluate the lesions in lung and peripheral immune organs of pigs infected with different virulence PRRSV strains,piglets were inoculated with HuN4 strain and CH-1a strain,respectively.Blood samples,lung,submandibular lymph nodes(SLN),inguinal lymph nodes(ILN),mesenteric lymph node(MLN),tonsil and spleen were collected at different days post inoculation(d.p.i).The clinical signs,pathological changes,virus load in immune organs and antibodies responses were evaluated.The results showed that the virus load in lung and peripheral immune organs of the piglets infected with HuN4 strain was significantly higher in comparison with the piglets infected with CH-1a strain.Histopthologic examination showed that the lymphocytes were significantly reducedin lymph nodes of HuN4 group.These results suggest that lesions in lung and peripheral immune organs of piglets infected with HuN4 strain were more serious than that of piglets infected with CH-1a strain.