神經壞死病毒感染石斑魚鰭細胞株之超顯微病理變化

Ultrastructural Changes of Nervous Necrosis Virus Infected Grouper Fin Cell Line Observed by Transmission Electron Microscope

鄭穹翔(Chiung-Hsiang Cheng) ； 邱顯傑(Hsien-Chieh Chiu) ； 張繼堯(Chi-Yao Chang) ； 郭應誠(lng-Chreng Guo)

《中華民國獸醫學會雜誌》 26卷2期 (2000/06) Pp. 117-123

https://doi.org/10.7009/JTCSVS.200006.0117

摘要

病毒性神經壞死症造成國內水產養殖業重大的經濟損失。罹病魚苗在臨床上呈現厭食及異常泳姿，如在水面迴旋游泳及翻滾等神經症狀。為檢測該病症之感染原及了解其致病機制，本實驗室自發病魚場的病魚中採集腦及眼睛等臟器進行反轉錄聚合酵素連鎖反應檢測，經證實為神經壞死病毒的感染。以病魚臟器研磨製成之乳劑感染石斑魚鰭細胞株，經72小時後約有80％的細胞產生細胞病變效應，受感染的細胞在細胞質中形成許多空泡且有腫脹的情形；將細胞刮下進行穿透式電子顯微鏡觀察，發現在細胞質中散佈著病毒顆粒以及大小不一的空泡，其內被病毒顆粒充滿、半滿或全空，且病毒顆粒被膜系胞器所包圍而形成質內包函體，而在其中的病毒顆粒呈現類晶體狀的整齊排列。此病毒不具有外套膜，型態介於圓形與二十面體之間，病毒直徑大小約為25-27nm。穿透式電子顯微鏡的觀察驗證此病毒是在細胞質進行複製，且藉由破壞細胞的膜系胞器以及促使細胞質形成大量空泡而造成細胞病變。藉由以上的實驗方法，本實驗成功地利用已經建立之石斑魚鰭細胞株對於神經壞死病毒感染進行超顯微之細胞病變觀察。

關鍵字

病毒性神經壞死症 ； 神經壞死病毒 ； 石斑魚鰭細胞 ； 穿透式電子顯微鏡

並列摘要

In southern Taiwan viral nervous necrosis (VNN), which results from infection by nervous necrosis virus (NNV), has caused numerous mortalities of hatchery-reared grouper larvae. Histopathologically, the disease is characterized by vacuolation in the spinal cord, brain, and retinal tissues. To gain a better understanding of the pathogenesis of VNN, cytopathic effects of NNV on infected grouper fin cells were studied with the use of a transmission electron microscope. The diseased grouper larvae, sampled from southern Taiwan, were diagnosed with having NNV, which was identified by RT-PCR amplification and product sequencing. The 0.22µm filtrated tissue emulsions of the diseased grouper larvae were then used to infect grouper fin cells. 72-hours after infection cytopathic effects (CPE) were observed. Transmission electron microscopy illustrated that the cytoplasm of infected cells was filled with vacuoles and viral particles, which were enclosed in bilayer membrane as inclusion bodies. The viral particles were of typical morphology of NNV, that is, they were round to icosahedral, unenveloped, and 25-27nm in diameter. We speculated that the vacuolation that occurred in the cells with CPE resulted from acute replication of NNV in the infected cells, therefore causing the cells to die. In this paper, we have delineated ultrastructural changes of the NNV infected grouper fin cell line by transmission electron microscope.

並列關鍵字

Viral nervous necrosis ； Nervous necrosis virus ； Grouper fin cell ； Transmission electron microscope