Isolation and identification of Singapore grouper iridovirus Hainan strain (SGIV-HN) in China
Isolation and identification of Singapore grouper iridovirus Hainan strain (SGIV-HN) in China
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DOI：
10.1007/s00705-019-04268-z
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发表时间：
2019-07-01
影响因子：
2.7
通讯作者：
Qin, Qiwei
中科院分区：
文献类型：
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作者：
Wei, Jingguang;Huang, Youhua;Qin, Qiwei
近年来，随着海洋养殖活动的快速发展，病毒性疾病的爆发影响了石斑鱼养殖业，造成了重大的经济损失。新加坡石斑鱼虹膜病毒（SGIV）是鱼类中最重要的致病病毒之一。在本研究中，我们从患病的石斑鱼中分离并鉴定了一种病毒，方法是将感染的组织细胞与石斑鱼脾脏细胞共培养。分离得到的病毒基因组与GenBank数据库中SGIV参考株的核苷酸序列同源性为99.83%。该病毒基于主要衣壳蛋白（MCP）氨基酸序列构建进化树，与SGIV聚类，因此被命名为“海南新加坡石斑鱼虹膜病毒”（SGIV- hn）。为评价SGIV-HN在鱼类中的致病性，采用腹腔注射感染橙斑石斑鱼的方法。感染的石斑鱼从感染后的第四天开始死亡，幸存者往往在第八天稳定下来。死亡率为83.33%。在模拟感染的对照组中，只有2条鱼死亡，死亡率为6.67%。解剖显示脾脏肿大出血，吉氏染色可见肿大的细胞。这是中国首次从自然感染的鱼类中分离出SGIV，我们表明SGIV- hn具有高度传染性，导致石斑鱼大量死亡。
In recent years, with the rapid development of marine farming activities, outbreaks of viral diseases have affected the grouper aquaculture industry, causing heavy economic losses. Singapore grouper iridovirus (SGIV) is one of the most important viruses causing disease in fish. In the present study, we isolated and identified a virus from diseased groupers by coculturing the affected tissue cells with grouper spleen cells. The genome of the isolated virus shared 99.83% nucleotide sequence homology with those of SGIV reference strains in the GenBank database. The virus clustered with SGIV on an evolutionary tree constructed based on major capsid protein (MCP) amino acid sequences, so it was designated Singapore grouper iridovirus Hainan' (SGIV-HN). To evaluate the pathogenic potential of SGIV-HN in fish, orange-spotted groupers were infected by intraperitoneal injection with the virus. Infected groupers began to die from the fourth day after infection, and survivors tended to be stable by the eighth day. The death rate was 83.33%. In a mock-infected control group, only two fish died, and the mortality rate was 6.67%. Dissection showed that the fish had enlarged spleenswith hemorrhage, and enlarged cells were visible with Giemsa staining. This is the first report of isolation of SGIV from naturally infected fish in China, and we show that SGIV-HN is highly infectious, causing massive deaths in groupers.