摘要
为了解乙型脑炎 (乙脑 )减毒活疫苗弱毒株SA14 14 2神经毒力的减弱程度 ,本文对弱毒株及其原株SA14强毒株进行了猴体和小白鼠的致病性和病理学变化的比较试验。SA14强毒株病毒 (原始滴度 6 15× 10 8/ml) ,以10 -2 和 10 -4 ～ 10 -7不同稀释度于丘脑两侧合并脊髓注射恒河猴 ,每组除 10 -4 1只外其余均为 2只。另以 10 -4 和10 -6～ 10 -8不同稀释度脑内注射小鼠 ,每组 8只。结果猴子除 10 -4 1只外其余全部发病死亡 ,小鼠则全部死亡。SA14 14 2以 1∶5稀释病毒 (原始滴度为 8× 10 6/ml)按同样方法注射 4只猴和 30只小鼠 ,结果全部存活。另以SA1410 -2 病毒皮下注射 3只猴未死亡 ,而以 10 -1皮下注射 30只小鼠时则全部死亡。SA14 14 2以 1∶5稀释病毒皮下注射小鼠时则全部存活。病理组织学结果显示二种动物接种SA14株强毒后主要表现为弥散性脑脊髓炎 ,以神经细胞坏死为其主要特征和最突出的病变。猴子的病变以脊髓前角、丘脑和中脑黑质为重 ,小鼠的病变则以大脑皮质、海马部最重 ,脊髓的病变却比脑轻。接种弱毒株的动物则仅有轻微炎症反应、神经细胞坏死极少出现。以上结果表明以脑内接种时恒河猴和小鼠对乙脑病毒均高度敏感 ,以皮下接种时小鼠的敏感性高于猴子。乙脑SA14 14
In order to study the attenuation of neurovirulence of SA14 14 2 attenuated vaccine virus,monkeys and mice were tested with the strain and its parent SA14 virulent strain.Several dilutions(10 -2 and 10 -4 to 10 -7 )of SA14 virulent strain were inoculated in rhesus monkeys by combined intrathalamical(each thalamus 0.5 ml)and intraspinal(0.2 ml at lumbar site) inoculation,for each dilution 2 monkeys.Another 3 monkeys tested subcutaneously(SC) with a 10 -2 dilution of the strain.The SA14 14 2 in 1∶5 dilution was the same as method in 4 monkeys.Mice were inoculated intracerebrally(IC)with 10 -4 and 10 -6 to 10 -8 dilution SA14 strain,each 8 mice.Another 30 mice were inoculated SC with a 10 dilution of the strain.SA14 14 2 in 1∶5 dilution was tested in mice by IC and SC,each 30 mice. The results revealed that monkeys and mice inoculated with SA14 strain by IC route which developed neurological symptoms and died,while those receiving the attenuated SA14 14 2 virus all survived.By SC inoculation,all mice developed symptoms and died after infected with SA14 strain,on the other head all mice remained healthy after inoculation of SA14 14 2 strain.As for pathological changes,monkeys and mice receiving virulent SA14 strain were induced disseminated encephalomyelitis,neuron necrosis was the most characteristic and prominent histopathologic lesions.In monkeys the lesions mainly distributed in the anterior horn of spinal cord,thalamuses and substantia nigra of midbrain,however there were mainly located in cerebral cortex and hippocampus in mice.Compared with SA14,SA14 14 2 strain only induced minor inflammation reaction limited in certain sites and neuron necrosis was seldom found. This study confirms that the neurovirulence of SA14 14 2 attenuated strain is remarkably decreased,it is reliable to predict the safety of this strain to humans beings is reliable.This results also indicate that mouse is more susceptible to JE virus than monkey,therefore mice can be substituted for monkeys when screening the lots of JE attenuated vaccine for possible reversion to neurovirulence.
出处
《微生物学免疫学进展》
2000年第4期1-4,共4页
Progress In Microbiology and Immunology
关键词
乙型脑炎病毒
SA14-14-2
减毒株
致病性
病理学
Japanese encephalitis
SA14 14 2 attenuated and its parent SA14 virus
Monkeys and mice
Pathogenicity
Histopathology.
