• Journal of fish pathology
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• v.7 no.1
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• pp.13-22
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• 1994

To identify the immunogens of a PRT strain of Infectious Hematopoietci Necrosis Virus (IHNV) isolated from cultrued fish in Korea (Park et al, 1993). a panel of 4 monoclonal antibodies (MAbs) against IHNV-PRT strain and two polyclonal antisera from rainbow trout survived IHN disease were prepared. Proteins of purified IHNV-PRT strain were analysed on 10% SDS-PAGE and transferred onto NC paper and were incubated with the antibody solutions. With the polyclonal antibodies, four bands ($M_1$, $M_2$, G and 90Kd) were detected and the band density was in the order of $M_2$ > 90Kd > $M_1$ > G. However, with the MAbs, only two bands(G and 90Kd) were detected. The origin of 90Kd protein was not clear but maybe cell. All the results represented that among the five proteins of IHNV-PRT strain (Park et al., 1993), $M_2$, $M_1$ and G proteins were immunogens and $M_2$ protein was the strongest one.

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

• Journal of fish pathology
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• v.26 no.3
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• pp.283-287
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• 2013

The susceptibility of marine medaka, Oryzias dancena to fish pathogenic viruses (infectious pancreatic necrosis virus (IPNV), viral hemorrhagic septicemia virus (VHSV), hirame rhabdovirus (HIRRV), infectious hematopoietic necrosis virus (IHNV), and lymphocystis disease virus (LCDV)) was investigated. The cumulative mortalities of fish immersed with IPNV (experimental condition: $15^{\circ}C$ sea water (SW)), VHSV ($15^{\circ}C$ SW), HIRRV ($15^{\circ}C$ fresh water (FW)) were 30%, 40% and 60%, respectively. In the fish immersed with IPNV ($15^{\circ}C$ FW, $18^{\circ}C$ FW and SW), VHSV ($15^{\circ}C$ FW, $18^{\circ}C$ FW and SW), HIRRV ($15^{\circ}C$ SW), IHNV ($15^{\circ}C$ FW and SW), LCDV ($15^{\circ}C$ FW and SW, $18^{\circ}C$ FW and SW), and mock-challenged group, mortality rate was less than 10%. IPNV, VHSV and HIRRV were re-isolated from the dead fish. These results suggest that marine medaka is susceptible to IPNV, VHSV and HIRRV, although their susceptibility depends on the environmental conditions.

• Journal of fish pathology
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• v.25 no.3
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• pp.257-262
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• 2012

A reverse transcriptase loop-mediated isothermal amplification (RT-LAMP) assay was evaluated to monitor infectious hematopoietic necrosis virus (IHNV) from artificially infected rainbow trout Oncorhynchus mykiss. The cumulative mortalities of fish challenged with IHNV at $10^{6.5}\;TCID_{50}$/fish, $10^{5.5}\;TCID_{50}$/fish and $10^{4.5}\;TCID_{50}$/fish were 40%, 0% and 0%, respectively. Dead fish and survivors at 16 and 28 d post-challenge in each group were employed for IHNV detection by RT-LAMP assay and virus isolation using BF-2 cells. IHNV from $10^{4.3}$ to $10^{6.8}\;TCID_{50}/ml$ was isolated from all the dead fish and also detected in all of the examined dead fish by RT-LAMP assay. In survivors at 16 d, 60% (3/5 fish, $10^{2.8}-10^{5.05}\;TCID_{50}/ml$), 20% (1/5 fish, $10^{1.05}\;TCID_{50}/ml$) and 60% (3/5 fish, $10^{1.05}-10^{4.8}\;TCID_{50}/ml$) were found to be IHNV-positive by virus isolation in fish challenged with IHNV at $10^{6.5}\;TCID_{50}$/fish, $10^{5.5}\;TCID_{50}$/fish and $10^{4.5}\;TCID_{50}$/fish, respectively, while 20% (1/5 fish), 0% (0/5 fish) and 20% (1/5 fish) were IHNV-positive by RT-LAMP assay. No IHNV was detected in the survivors at 28 d and control fish. These results indicate that the RT-LAMP assay is useful for detection of IHNV in diseased fish although it is not enough to monitor virus in IHNV-survivors.

• Fisheries and Aquatic Sciences
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• v.8 no.3
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• pp.185-187
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• 2005

We tested the in vivo ability of a DNA chip to detect virus-specific genes from virus-infected olive flounder Paralichthys olivaceus and rainbow trout Oncorhynchus mykiss. Target cDNA was obtained from total RNA of virus infected cell lines by reverse transcription (RT) and was labeled with fluorescent dye (Cy5-dUTP). The results show the successful detection of infectious hematopoietic necrosis virus (IHNV) and viral hemorrhagic septicaemia virus (VHSV) genes in the virus-infected fishes.

• Journal of fish pathology
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• v.34 no.2
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• pp.123-131
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• 2021

This study investigated the phylogenetic classification and pathogenicity of 6 infectious hematopoietic necrosis virus (IHNV) strains isolated from salmonid fish in Gangwon-do, Korea. Based on the nucleotide sequence of mid-G region, all six strains belong to J genotype, of which 5 are J-Nagano type and 1 J-Shizuoka type. In a challenge test, 5 isolates of J-Nagano type IHNV showed a various mortalities as 2 isolates induced a high mortality of 100% and the other 3 isolates induced mortalities of 50, 30, and 20% after intraperitoneal injection in rainbow trout (Oncorhynchus mykiss). Meanwhile no mortality was occurred by 1 isolate of J-Shizuoka type virus. Thus, it seems that there might be no relation between genotype and pathogenicity within IHNV J genotypes. This is contrary to previous studies where reported a higher pathogenicity of J-Shizuoka type virus than J-Nagano type virus in rainbow trout. Further examination will be required to clarify this since only one J-Shizuoka type virus was analyzed in this study.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2003.05a
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• pp.313-314
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• 2003

Antiviral DNA vaccine carrying a gene for a major antigenic viral protein have received considerable attention as a new approach in vaccine development. For fish viruses effects of DNA vaccine encoding viral G gene of infectious hematopoietic necrosis virus(IHNV) and viral hemorrhagic septicemia virus (VHSV)have been demonst.ated previously(Lapatra et al., 2001) Hirame rhabdovirus (HIRRV) causes hemorragic disease on flounder. (omitted)

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

• Journal of fish pathology
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• v.16 no.2
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• pp.81-90
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• 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
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• v.28 no.2
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• pp.113-116
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• 2015

A $0.45-{\mu}m$ membrane filter is generally used to remove bacterial contamination during virus extraction from fish samples. However, the number of fish viruses is drastically reduced after filtration with a $0.45{\mu}m$ filter. In this study, we investigated the effect of filters on virus infectivity titer and the change in virus titer and bacterial number following different centrifugation conditions to determine a suitable procedure for virus extraction from fish samples. $10^{4.05}$ and $10^{5.05}TCID_{50}/ml$ of infectious hematopoietic necrosis virus (IHNV) and $10^{4.05}$ and $10^{4.55}TCID_{50}/ml$ of Oncorhynchus masou virus (OMV) were not detectable after filtration with two types of $0.45-{\mu}m$ filters, except the IHNV titer was reduced by about 10 fold after filter use (company A). No significant difference was found in the virus titer following centrifugation at $880{\times}g$ (30 min) or $3,500{\times}g$ (30 min), whereas IHNV and OMV titers were reduced by about 10 and 10-1000 fold by centrifugation at $14,000{\times}g$ (30 min) and $14,000{\times}g$ (10 and 30 min), respectively. A total of 97.7-99.9% Escherichia coli were eliminated by centrifugation at $880 {\times}g$ (30 min) and $3,500{\times}g$ (30 min). These results show that fish viruses were affected by filtering, even though the effect differed by virus species and filter type. Therefore, centrifugation at $3,500{\times}g$ (30 min) and use of medium with antibiotics may be useful for virus extraction along with a reduction in bacteria.