DAO 78:209-215 (2008)  -  doi:10.3354/dao01879

Outbreaks and risks of infectious spleen and kidney necrosis virus disease in freshwater ornamental fishes

Joon Bum Jeong1, Ho Yeoul Kim1, Lyu Jin Jun1, Ji Hyo Lyu1, Nam Gyu Park2, Joong Kyun Kim2, Hyun Do Jeong1,*

1Department of Aquatic Life Medicine, and 2Department of Biotechnology and Bioengineering, Pukyong National University, 599-1 Dae Yeon Dong, Nam Ku, Busan 608-737, South Korea
*Corresponding author. Email:

ABSTRACT: We examined the distribution of iridoviruses in 10 freshwater ornamental fish species hatched in Korea and imported from other Asian countries using both 1-step and 2-step polymerase chain reation (PCR). None of the 10 fish species analyzed were free of iridovirus as shown by 2-step PCR positive results, and 3 species yielded 1-step PCR positive results with associated mortality. Cloned PCR amplicons of the adenosine triphosphatase (ATPase) and major capsid protein (MCP) genes in genomic DNA of iridovirus showed the same nucleotide sequences as that of infectious spleen and kidney necrosis virus (ISKNV) isolated from the mandarinfish Siniperca chuatsi. These results indicate the presence of ISKNV disease in various ornamental fish as new host species and that the disease is widespread throughout different Asian countries including Korea, Singapore and China. Such infections were either clinical with associated mortality (and 1-step PCR positive) or asymptomatic in fish that were externally healthy (and only positive in 2-step PCR). Molecular analyses of the K2 region performed on iridovirus samples isolated from freshwater ornamental fishes revealed deletion/insertion of repetitive sequences of various lengths (42 to 339 bp), depending on the ISKNV isolates, without substitutions. Experimental infection of pearl gourami Trichogaster leeri and silver gourami T. microlepis with a tissue homogenate of pearl gourami infected by ISKNV induced 70 and 20% cumulative mortalities in the pearl and silver gourami, respectively.


KEY WORDS: Iridovirus · ISKNV · Ornamental fish · Asymptomatic infection · Asian countries


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Cite this article as: Jeong JB, Kim HY, Jun LJ, Lyu JH, Park NG, Kim JK, Jeong HD (2008) Outbreaks and risks of infectious spleen and kidney necrosis virus disease in freshwater ornamental fishes. Dis Aquat Org 78:209-215

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