Ksiazek T G, Hardy J L, Reeves W C
Am J Trop Med Hyg. 1985 May;34(3):578-85. doi: 10.4269/ajtmh.1985.34.578.
Titers of Turlock (TUR) and Hart Park (HP) viruses were reduced to undetectable levels when virus was mixed with a triturated suspension of uninfected (normal) 4th instar larvae of Culex tarsalis prior to plaque assay in cell culture. There was a linear relationship between the number of larvae in the pool and the titer of virus recoverable. Virus was undetectable when 1,000-10,000 PFU of either agent was added to pools that contained 25 or more larvae. Suspensions of up to 25 adult male or female Cx. tarsalis had little effect on detectable viral titers while pupal suspensions had an intermediate effect. The inhibitory effect of normal larval extracts on viral infectivity could be counteracted by use of polycations or a high pH buffer. A similar reduction in titer of TUR virus was observed with extracts of larvae of Aedes melanimon or Anopheles franciscanus. Larval extracts of Cx. tarsalis similarly reduced titers of California and St. Louis encephalitis viruses but not western equine encephalomyelitis virus. These findings may have significant bearing on the interpretation of transovarial transmission attempts in which pooled larvae are assayed for virus.
在细胞培养中进行蚀斑测定之前，将特洛克（TUR）病毒和哈特帕克（HP）病毒与未感染（正常）的致倦库蚊四龄幼虫的研磨悬浮液混合时，病毒滴度降低到无法检测的水平。混合幼虫的数量与可回收病毒的滴度之间存在线性关系。当向含有25只或更多幼虫的混合液中加入1000 - 10000个PFU的任何一种病毒时，均检测不到病毒。多达25只成年雄性或雌性致倦库蚊的悬浮液对可检测到的病毒滴度影响很小，而蛹的悬浮液则有中等程度的影响。正常幼虫提取物对病毒感染性的抑制作用可以通过使用聚阳离子或高pH缓冲液来抵消。用黑尾伊蚊或嗜人按蚊幼虫提取物观察到TUR病毒滴度有类似降低。致倦库蚊幼虫提取物同样降低了加利福尼亚脑炎病毒和圣路易斯脑炎病毒的滴度，但对西部马脑炎病毒滴度没有影响。这些发现可能对在检测混合幼虫中病毒的经卵传播试验的解释有重要意义。
