Abstract
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 spleens with 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.
References
Huang XH, Huang YH, Sun JJ, Han X, Qin Q (2009) Characterization of two grouper Epinephelus akaara cell lines: application to studies of Singapore grouper iridovirus (SGIV) propagation and virus-host interaction. Aquaculture 292:172–179
Qin QW, Lam TJ, Sin YM, Shen H, Chang SF, Ngoh GH, Chen CL (2001) Electron microscopic observations of a marine fish iridovirus isolated from brown-spotted grouper, Epinephelus tauvina. J Virol Methods 98:17–24
Qin QW, Shi C, Gin KY, Lam TJ (2002) Antigenic characterization of a marine fish iridovirus from grouper, Epinephelus spp. J Virol Methods 106:89–96
Qin QW, Chang SF, Ngoh-Lim GH, Gibson-Kueh S, Shi C, Lam TJ (2003) Characterization of a novel ranavirus isolated from grouper Epinephelus tauvina. Dis Aquat Organ 53:1–9
Wei J, Zhang X, Zang S, Qin Q (2017) Expression and functional characterization of TRIF in orange-spotted grouper (Epinephelus coioides). Fish Shellfish Immunol 71:295–304
Wei J, Li C, Zhang X, Zhou S, Zang S, Wei S, Qin Q (2018) Molecular cloning and characterization of Aos1 and Uba2 from the orange-spotted grouper (Epinephelus coioides). Fish Shellfish Immunol 81:343–353
Funding
This study was supported by grants from the National Key R&D Program of China (2018YFC0311302 and 2018YFD0900501), China Agriculture Research System (CARS-47-G16), Science and Technology Planning Project of Guangdong Province, China (2015TQ01N118), and Science and Technology and Industrial Development Marine Fishery Project of Guangdong Province, China (A201501C01).
Author information
Authors and Affiliations
Corresponding author
Ethics declarations
Conflict of interest
The authors declare that they have no competing interests.
Ethics approval and consent to participate
The grouper sampling and experiments were approved by the tab of the Animal Care and Use Committee of College of Marine Sciences, South China Agricultural University (HYXY20180501 (SCAU)).
Additional information
Handling Editor: T. K. Frey.
Publisher's Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Rights and permissions
About this article
Cite this article
Wei, J., Huang, Y., Zhu, W. et al. Isolation and identification of Singapore grouper iridovirus Hainan strain (SGIV-HN) in China. Arch Virol 164, 1869–1872 (2019). https://doi.org/10.1007/s00705-019-04268-z
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00705-019-04268-z