• Journal of Life Science
• /
• v.31 no.6
• /
• pp.574-580
• /
• 2021

This study investigated the pathogenicity of different genotypes of infectious hematopoietic necrosis virus (IHNV) strains isolated from infected rainbow trout in Gangwon Province. RtPc0314c and RtPc0314g strains belonging to the JRt-Shizuoka lineage and RtPc0816g strain belonging to the JRt-Nagano lineage showed 100% cumulative mortality when inoculated at a high titer. In addition, more rapid necrosis was observed in rainbow trout infected with RtPc0314c and RtPc0314g mutations. When inoculated at a low titer, 100% mortality was not observed until the end of the experiment, but the mortality was higher in rainbow trout infected with a mutant strain belonging to the JRt-Shizuoka linage than a mutant strain belonging to the JRt-Nagano lineage. A histopathological analysis showed a clear signature of infection in kidney and spleen tissues upon infection with RtPc0314c and RtPc0314g but no signature of infection associated with the Rt03186 strain. Based on the results in this study, it seems that strains belonging to the JRt-Shizuoka lineage in Gangwon Province IHNV are more pathogenic.

• Food Science and Biotechnology
• /
• v.17 no.5
• /
• pp.1074-1078
• /
• 2008

To investigate the antiviral activity of marine algae against fish pathogenic viruses, which are often the causes of viral disease in aquaculture, the 80% methanolic extracts of 21 species collected from the coast of Korea were screened for their in vitro antiviral activities on infectious hematopoietic necrosis virus (IHNV) and infectious pancreatic necrosis virus (IPNV), using a flounder spleen (FSP) cell-line. Among them, Monostroma nitidum (10 ${\mu}g/mL$) exhibited the strongest inactivation on IHNV, showing a 2 log reduced virus titre as compared to the control in the determination of direct virucidal activity. In addition, Polysiphonia morrowii (100 ${\mu}g/mL$) remarkably reduced the virus titres of treated cells by 2-2.5 log, for both IHNV and IPNV, in the determination of cellular protective activity, implying the existence of substances that may modulate innate host defense mechanisms against viral infections. These results reveal that some marine algae could be promising candidates as sources of antiviral agents or as health-promoting feeds for aquaculture.

• Korean Journal of Ichthyology
• /
• v.27 no.3
• /
• pp.183-188
• /
• 2015

Recently, mariculture of rainbow trout (Oncorhynchus mykiss) has been initiated in the coast areas of Korea. In the present study, we investigated the effect of fish viruses on mariculture of rainbow trout. The pathogenicity of infectious hematopoietic necrosis virus (IHNV) and infectious pancreatic necrosis virus (IPNV) isolated from freshwater rainbow trout was tested against major cultured marine fish species, including olive flounder (Paralichtys olivaceus), rock fish (Sebastes schlegeli), rock bream (Oplegnathus fasciatus), red seabream (Pagrus major) and sevenband grouper (Epinephelus septemfasciatus). The pathogenicity of marine birnavirus (MABV), hirame rhabdovirus (HIRRV) and nervous necrosis virus (NNV) isolated from marine fish species was also tested against rainbow trout. No mortality was observed in marine fish species challenged with IHNV or IPNV. However, olive flounder and rock bream were infected by IHNV and IPNV. A mortality of 8.3% was observed in rainbow trout challenged with HIRRV. The fish was infected by both MABV and NNV. These results suggest that the mariculture of rainbow trout might be affected by fish viruses.

• Journal of fish pathology
• /
• v.31 no.2
• /
• pp.81-85
• /
• 2018

Fetal bovine serum (FBS) is an essential element of cell growth and can also affect the viral replication. In this study, we tried to find out whether FBS concentration affects the viral infectivity titer of IHNV and IPNV. EPC cells were suspended with MEM supplemented with various concentrations of FBS (MEM0, MEM2, MEM5 and MEM10) and cultured in 96-well plate. Each virus was 10-fold diluted virus and inoculated in 96-well plate. The highest infectivity titer of IHNV was $10^{7.88}\;TCID_{50}/mL$ in 96-well plate using MEM5 and the lowest one was $10^{7.30}\;TCID_{50}/mL$ in 96-well plate using MEM10. The highest infectivity titer of IPNV was $10^{7.47}\;TCID_{50}/mL$ in 96-well plate using MEM5 and the lowest one was $10^{6.97}\;TCID_{50}/mL$ in 96-well plate using MEM10. This study showed that not only 0% FBS but 10% FBS leads low infectivity titer of IHNV and IPNV. Therefore, it is considered that the desirable concentration of FBS is 2% or 5% for measurement of infectivity titer of IHNV and IPNV.

• Journal of fish pathology
• /
• v.16 no.2
• /
• pp.81-90
• /
• 2003

High mortality with signs similar to viral haemorrhagic septicemia (VHS) such as severe haemorrhages in the skin, muscle and air bladder occurred in the farmed adult rainbow trout, Oncorhynchus mykiss, in Ku-mi and Je-chun area in Korea. The isolates were neutralized by an antiserum against IHNV but not by antisera against VHSV. Electron micrograph of an ultrathin section showed large numbers of bullet-shaped virus particles. The newly isolated rhabdovirus was composed of five structural proteins. In the western blot analysis Ihe anti-DiNV serum strongly reacted with G. N and MI protein. The cumulative mortalities of RTK infected rainbow trout (10-12cm.9-12g) with $10^{3.5}\;and\;10^{1.5}TCID_{50}/m{\ell}$ were 80% and 30%. respectiveIy_ RTJ infected fish showed 50% mortality by infection with $10^{3.5}TCID_{50}/m{\ell}$. Control group and IHNVChAb exhibited no mortality. From these results, the viruses were identified lHNV although diseased fish showed similar sign. with VHS and caused high mortality in large-sized fish.

• Journal of fish pathology
• /
• v.37 no.1
• /
• pp.9-15
• /
• 2024

An enzyme-linked immunosorbent assay (ELISA) with two Novirhabdovirus antigens (viral hemorrhagic septicemia virus, VHSV and infectious hematopoietic necrosis virus, IHNV) was used to detect specific antibodies against VHSV from olive flounder (Paralichthys olivaceus) sera. In ELISA plates with VHSV culture supernatants (VHSV-Ag plate), optical density (OD) values for sera from olive flounder with VHS history (VHS sera) ranged from 0.64±0.36, and those of sera from fish without VHS history (non-VHS sera) ranged from 0.26±0.26. In IHNV-Ag plate, the OD values (0.43±0.28) for VHS sera were quite low compared to those in VHSV-Ag plates, while the OD values for non-VHS sera were almost similar. When the OD values for each serum were calculated by subtracting the OD values in the IHNV-Ag plate from those in the VHSV-Ag plate, the corrected OD values were significantly different between VHS sera and non-VHS sera. The results were completely in line with fish histories of VHS epizootics. It was considered that the corrected OD values may represent the true values recognized by VHSV-specific antibodies.

• Proceedings of the Korean Society of Fisheries Technology Conference
• /
• 2002.05a
• /
• pp.555-556
• /
• 2002

• Journal of Life Science
• /
• v.3 no.4
• /
• pp.209-215
• /
• 1993

어류의 대량폐사의 원인은 여러 가지가 있을 수 있는데 가장 중요한 것 중의 하나가 바이러스 감염에 의한 것이다. 우리나라 송어양식의 경우, 바이러스성 질병에 의한 대량폐사가 발생하여 매년 수천만마리의 치어가 폐사되어 왔는데 이 질병의 원인을 조사한 결과, 전염성 췌장 괴사 바이러스(Infectious Pencreatic Necrosis Virus ; IPNV)와 전염성 조혈기 괴사 바이러스(Infectious Hematopoietic Necrosis Virus ; IHNV)가 분리되어 이들의 대량폐사의 병원체임읠 밝혀내었다. 따라서 본 총설에서는 연어과 어류중 양식 대상종인 무지개송어 양식시 전염성과 병원성이 강해 치어기에 들어 대량폐사를 유발시키는 IHNV에 대해 최근 연구 결과를 중심으로 바이러스 분리 및 동정, 신속진단, 바이러스 백신 기초 기술 개발순으로 기술하고자 한다.

• Proceedings of the Korean Aquaculture Society Conference
• /
• 2006.05a
• /
• pp.522-523
• /
• 2006

• Proceedings of the Korean Aquaculture Society Conference
• /
• 2006.05a
• /
• pp.491-493
• /
• 2006