猪繁殖与呼吸综合征病毒GXA毒株人工感染仔猪的病理学研究

目的]探讨PRRSV-GXA毒株对断奶仔猪的致病性。方法]将12头PRRSV/PCV2抗体和抗原阴性的健康仔猪随机分为感染组（9头）和对照组（3头）,感染组通过口服和肌肉注射方式接种PRRSV-GXA株细胞毒（4ml/头）,对照组接种无病毒的细胞培养液（4ml/头）。感染后第11、14和21天分别剖杀感染组3头和对照组1头,根据临床症状、病理学变化、特异性抗体水平以及病毒核酸等判断其致病性。结果]仔猪感染PRRSV后第6～10天体温稍微升高,随后逐渐恢复至正常。早期出现短暂的精神沉郁,轻度厌食但没有出现典型临床症状。剖检的病理变化仅见于感染后第21天,有2头感染仔猪肺膈叶前缘出现小的局灶性间质性肺炎,镜检肺泡壁间质增宽,有多量单核细胞和淋巴细胞浸润。在感染后第9天检测到PRRSV特异性抗体,并随着时间呈上升趋势,感染后第21天达到较高值。在4头感染仔猪的肺脏及肺门淋巴结检测到病毒核酸,其中1头仔猪扁桃体也检测到病毒核酸。结论]PRRSV-GXA毒株对仔猪的毒力较弱,但能刺激机体产生较高水平特异性抗体。

Research on Pathology of Piglets Infected with GXA Strain of PRRSV

Objective] To investigate the pathgenicity of piglets infected with PRRSV GXA strain.Method] A total of 12 4-week-old healthy piglets which were negative of antibody and antigen of PRRSV/PCV2 were randomly divided into challenge group(9 piglets) and control group(3 piglets).GXA strain of PRRSV(4 ml/head) was inoculated intranasally and intranscularly simultaneously and cell culture medium of non RRRSV(4 ml/head) was inoculated in conteol group.Three piglets(in challenge group ) and one piglet(in control g...