• Fisheries and Aquatic Sciences
• /
• 제16권2호
• /
• pp.93-99
• /
• 2013

In 2009, a systemic megalocytivirus infection associated with high mortality was detected for the first time in cultured starry flounder Platichthys stellatus in Korea. Diseased starry flounder had pale bodies and gill coloring and enlarged spleens. Histopathological examinations revealed basophilic enlarged cells in various organs of diseased starry flounder. Polymerase chain reaction (PCR) was performed on tissue samples using three published primer sets developed for the red sea bream iridovirus. PCR products were detected for all primer sets, except 1-F/1-R, which are registered by the World Organization for Animal Health (OIE). The part of the gene corresponding to the full open reading frame encoding the viral major capsid protein (MCP) was amplified by PCR. PCR products of approximately 1,581 bp were cloned, and the nucleotide sequences were analyzed phylogenetically. The MCP gene of the starry flounder iridovirus, designated SFIV0909, was identical to that of the turbot reddish body iridovirus (AB166788).

• 한국어병학회지
• /
• 제32권2호
• /
• pp.49-57
• /
• 2019

본 연구에서는 2012년부터 2018년 1월까지 국내 어류에서 참돔이리도바이러스병 (red sea bream iridoviral disease; RSIVD) 으로 확정 진단된 주요 분리주에 대하여 major capsid protein (MCP) 유전자의 염기서열을 바탕으로 Megalocytivirus의 유전적 관계를 명확히 했다. 또한, Megalocytivirus와 숙주 세포간 상호작용에 영향을 줄 수 있는 특이 유전자 2종, Vascular endothelial growth factor (VEGF) 및 Histidine triad motif인 HIT-like 단백질 (HIT)에 대한 염기서열 분석을 통해 유전적 상관관계를 고찰하였다. 국내 어류에서 분리된 39개의 megalocytiviruses는 2가지 유전형인 red sea bream iridovirus (RSIV)형과 turbot reddish body iridovirus (TRBIV)형으로 분류되었으며, RSIV형의 megalocytiviruses는 다시 유전아형인 RSIV-subgroup 1형과 2형으로 분류되었다. 그리고 VEGF 유전자 염기서열 분석 결과에서는 RSIV형의 바이러스에서 변이가 발생되었음을 확인할 수 있었으며, HIT-like 단백질 유전자는 RSIV형의 Megalocytivi rus에서만 발견되는 것을 알 수 있었다.

• 한국어병학회지
• /
• 제34권2호
• /
• pp.149-159
• /
• 2021

Genus Megalocytivirus cause red sea bream iridoviral disease (RSIVD) and scale drop disease (SDD). Based on the phylogeny of the major capsid protein (MCP) and adenosine triphosphatase (ATPase) genes, megalocytiviruses except for SDD virus (SDDV) could be three different genotypes, red sea bream iridovirus (RSIV), infectious spleen and kidney necrosis (ISKNV), and turbot reddish body iridovirus (TRBIV). In this study, primary cells derived from the caudal fin of rock bream (Oplegnathus fasciatus) grew at 25℃ in Leibovitz's medium supplemented with 10% (v/v) fetal bovine serum and primocin (100 ㎍/mL). Rock bream fin (RBF) cells exhibited susceptibility to infections by different genotypes of megalocytiviruses (RSIV, ISKNV and TRBIV) with the appearance of cytopathic effects with an increase in the viral genome copy number. Furthermore, compared to grunt fin (GF) cells, even though 10 times lower number of RSIV genome copies were inoculated in RBF cells, viral genome copy number produced on RBF cells were 44 times higher than that of GF cells at 7 d post-inoculation. As the isolated RBF cells are sensitive to different genotypes of megalocytiviruses (RSIV, ISKNV and TRBIV), they can be used for future studies regarding in vitro viral infection and subsequent diagnosis.

• Fisheries and Aquatic Sciences
• /
• 제24권11호
• /
• pp.351-359
• /
• 2021

The red sea bream iridovirus (RSIV) belonging to genus Megalocytivirus is responsible for red sea bream iridoviral disease (RSIVD) in marine and freshwater fishes. Although several diagnostic assays for RSIV have been developed, diagnostic sensitivity (DSe) and specificity (DSp) of real-time polymerase chain reaction (PCR) assays are not yet evaluated. In this study, we developed a TaqMan probe-based real-time PCR method and evaluated its DSe and DSp. To detect RSIV, the probe and primers were designed based on consensus sequences of the major capsid protein (MCP) genes from megalocytiviruses including RSIV, infectious spleen and kidney necrosis virus (ISKNV), and turbot reddish body iridovirus (TRBIV). The probe and primers were shown to be specific for RSIV, ISKNV, and TRBIV-types megalocytiviruses. A 95% limit of detection (LOD_95%) was determined to be 5.3 viral genome copies/µL of plasmid DNA containing the MCP gene from RSIV. The DSe and DSp of the developed real-time PCR assay for field samples (n = 112) were compared with those of conventional PCR assays and found to be 100% and 95.2%, respectively. The quantitative results for SYBR Green and TaqMan probe-based real-time PCR were not significantly different. The TaqMan probe-based real-time PCR assay for RSIV may be used as an appropriate diagnostic tool for qualitative and quantitative analysis.