Molitor T W, Schipper I A, Berryhill D L, Light M R
Can J Comp Med. 1979 Jul;43(3):280-7.
Various cell cultures were evaluated for their ability to support progressive pneumonia virus infection in vitro. Ovine trachea cells supported progressive pneumonia virus infection for an extended time,were extremely durable and could be passaged up until 30 passages. Progressive pneumonia virus infected ovine trachea cells were then used for the production of antigen for agar-gel immunodiffusion. A method for concentrating antigen, diafiltration, was compared to dialysis against polyethylene glycol. Using diafiltration, the concentrated virus was easily quantitated, less viscous (and therefore easier to apply) and only produced one precipitation line. Agar-gel immunodiffusion was used to survey 401 animals from two sheep flocks. One flock (96 sheep) was free of progressive pneumonia while the other flock had 111 of 305 total animals positive for precipitating antibodies. The incidence of precipitating antibodies in sheep ranged from 23% for yearling ewes to 80% in ewes seven years old.
对多种细胞培养物支持进行性肺炎病毒体外感染的能力进行了评估。绵羊气管细胞能长时间支持进行性肺炎病毒感染，极为耐用，传代可达30代。然后将感染了进行性肺炎病毒的绵羊气管细胞用于制备琼脂凝胶免疫扩散抗原。将一种浓缩抗原的方法——渗滤法，与用聚乙二醇透析法进行了比较。使用渗滤法时，浓缩病毒易于定量，粘性较小（因此易于应用），且仅产生一条沉淀线。用琼脂凝胶免疫扩散法对两个羊群的401只动物进行了检测。一个羊群（96只绵羊）无进行性肺炎，而另一个羊群的305只动物中有111只沉淀抗体呈阳性。绵羊中沉淀抗体的发生率从一岁母羊的23%到七岁母羊的80%不等。
