鸡传染性喉气管炎病毒SA_2株在鸡肾细胞中增殖规律的研究

Growth Pattern of Infectious Laryngotracheitis Virus-SA_2 Stain on Chicken Kidney Cells

传染性喉气管炎病毒SA2株系澳大利亚分离到的一株自然弱毒，该毒株具有良好的免疫原性和安全性。SA2可以在鸡肾细胞中良好增殖，潜伏期为12-18／小时，接种后30／小时达到增殖高峰，病毒价达106.2EID50／0.2ml，最大滴度持续至48／小时以后。SA2在鸡肾细胞上产生明显的细胞病变，病变特征为相邻感染细胞融合形成多核巨细胞，内含5-10个核。鸡肾细胞接种不同滴度的病毒，产生的细胞病变程度亦差异很大。接种量为106.5-7.5EID50SA2，48小时有90％以上鸡肾细胞可产生细胞病变;接种剂量若低于105.5EID50，接种120／小时也只引起部分鸡肾细胞出现细胞病变，不能波及整个细胞单层。通过对SA2株在鸡肾细胞中蚀斑形成影响因素的研究，建立了一种应用鸡肾细胞培养物对ILTV-SA2株蚀斑研究方法。结果发现，ILTV-SA2在鸡肾细胞中37℃吸附2小时达到最大吸附量，而且病毒浓度与病毒形成蚀斑数量呈直线关系，表明1个ILTV粒子可以产生1个蚀斑。

We studied the growth pattern and cytopathic effect of ILT-SA2 strain in chicken kidney cells. The result show that SA2 may reproduce finally on CK cells. After a latent period of 12～18 hours, there was an exponential rise in virus titer, which reached the peak level at around 30 hours. The peak titer is 106.2 EID50/0.2ml, which was maintained until 48 hours, at which time the growth experiment was terminated. The CPE of SA2 on CK cells, characterized by syncytia owing to coalescing by adjacent to infected cells,which included 5～10 nuclei. The CPE was obvious different, when the CK monolayer was inoculated with different dose virus,Seeded SA2 containing about 106.5 to 107.5 EID50, over 90% of CK cells was induced CPE at 48 hours pi; In contrast, eded SA2 containing less105.5 EID50,only some of CK cells was induced CPE, not involving the whole monolayer at 120 hours pi. We also studied the SA2 strain using adult chicken kidney cultures and agar overlay medium. It is discovered that the maximum adsorption of SA2 on CK cells was reached.2 hours after infection at 37℃. A linear relation was found between the concentration of virus inoculated and the number of plaques formed, indicating that 1 ILTV partcle produced 1 plaque.