【摘要】 1.实验比较了乙型脑炎病毒京卫研₁株,鸡胚适应株和中山株在空斑形成滴度与鼠脑LD₅₀滴度的比值,空斑形成的速率及空斑大小、分布的特征。 2.实验结果证明鸡胚适应株和中山株在上述特征方面较相似而与京卫研₁株有明显的不同。 3.对不同毒株空斑形成特征差异的原因进行了讨论,并认为组成京卫研₁株的病毒颗粒,按空斑形成情况来说较复杂,可能同时含有对小白鼠皮下致死力高低不同的病毒颗粒。更多还原

【Abstract】 The difference between plaque-forming titre and the mouse-brain LD₅₀ titre, theplaque forming rate, the rate of development of plaque and the distribution of differentplaque sizes of 3 strains （the A2 strain, the chick embryo adapted A₂ strain and theNakayama strain） of J. B. E. virus were studied. The experimental results indicated that the ratio of mouse-brain LD₅₀ titre to theplaque forming titre (LD₅₀/PFU) of these strains was different. It was observed thatthe ratio obtained from A₂ strain was greater than those of the other two strains, butno significant difference was observed between the adapted strain and Nakayama strain. The distributions of the sizes of plaques produced by these viruses were not iden-tical. In case of A₂ strain, they varied between 1.0-4.9 m.m., but most of them wereof 2.0 or 3.0 m.m. in diameter when observed on the 6th day after incubation. Onthe other hand, the size of plaques formed by the chick embryo adapted A₂ strain andNakayama strain ranged from 0.5-2.9 m.m. and 0.5-3.9 m.m. respectively, andmost of them were 2.0 and 1.0 m.m. in diameter. Concerning the rate of development in number and in size of the plaques formedby these strains during incubation, it was seen that the rate was evidently greater in A₂strain than those observed in the other two. Finally, the possible reasons for the differences in plaque-forming characteristics andthe relation of the plaque sizes to certain biological properties of these strains of J. B.E. virus especially in respect of A2 strain and the chick embryo adapted A₂ strain werediscussed.更多还原