摘要
目的通过蚊虫胸腔接种乙脑病毒减毒活疫苗SAl4-14-2株。了解该疫苗病毒在蚊虫体内的繁殖情况及其毒力稳定性，进一步评价该疫苗的安全性。方法建立三带喙库蚊的实验室种群，用SA14-14-2、SA14和中山株胸腔接种三带喙库蚊，感染后不同时间取一定数量的蚊虫。研磨制成悬液，用空斑试验检测蚊虫体内的病毒滴度。用感染蚊悬液接种乳鼠和感染蚊虫直接叮咬乳鼠的方法，观察对乳鼠的致病性。结果SAl4-14-2、SAl4和中山株病毒感染蚊虫后，第2～20d蚊虫体内均能检测到病毒，其中SA14-14-2株的滴度为2～3．72logPFU／ml，SAl4株为3～4．85logPFU／ml，中山株为3～5．40log-PFu／ml。中山株的感染滴度最高，其次是SA14株，SAl4-14—2株的感染滴度最低。表明蚊虫对野毒株（中山株和SA14株）更为敏感。感染SA14-14-2病毒的三带喙库蚊悬液接种乳鼠，未能引起乳鼠发病或死亡。感染SA14-14-2病毒的三带喙库蚊叮咬乳鼠，未见乳鼠发病或死亡，也未从小白鼠血清中检测到乙脑病毒抗体。结论经胸腔接种。SA14-14-2病毒能在三带喙库蚊体内稳定繁殖。动物接种和蚊虫叮咬试验表明，经蚊体内繁殖的SA14-14-2病毒毒力仍保持原有的弱毒特性，表明该减毒活疫苗通过蚊虫体内繁殖后不会造成传播。
To investigate the replication of Japanese encephalitis（JE） SA14-14-2 vaccine virus intrathoracicaUy inoculated to Culex tritaeniorhynchus mosquitoes and to determine its stability of viral.virulence in sucking mice in order to evaluate the safety of this vaccine, the laboratory colony of C. tritaeniorhynchus was set up and the JE SA14-14-2 vaccine virus, Nak and SA14 strain virus were inoculated intrathoracically. The virus titers in the inoculated mosquitoes were determined by plaque assay after different days of infecton, and the pathogenicity to sucking mice was observed by inoculation of the infected mosquito suspensions to sucking mice or by direct biting to sucking mice with the infected mosquitoes. It was found that all these 3 strains of viruses could be detected in C. tritaeniorhynchus by plaque assay within 2-20 days in which the virus titer of SA14-14-2 was lower （ 2.0-3.72 log） than those of its parent strain SA14 （3.0-4.85 log） and the wild strain of JE Nak virus （3.0-5.40 log） Neither illness nor death of mice could be found not only in mice inoculated with infected mosquito suspensions but also in mice directly bitten by the infected mosquitoes. These results indicate that, after intrathoracical infection, the attenuated JE SA14- 14-2 vaccine strain still remains its attenuated character when the viruses replicate in mosquitoes, suggesting that no transmis-sion of viruses can be induced when the attenuated vaccine strain of virus replicates in mosquitoes.
出处
《中国人兽共患病学报》
CAS
CSCD
北大核心
2007年第3期278-281,共4页
Chinese Journal of Zoonoses
