• 한국생물공학회:학술대회논문집
• /
• 2002.04a
• /
• pp.497-498
• /
• 2002

• 한국생물공학회:학술대회논문집
• /
• 2003.04a
• /
• pp.500-500
• /
• 2003

• Journal of fish pathology
• /
• v.6 no.2
• /
• pp.191-195
• /
• 1993

With the rapid progress in seed production techniques, aquaculture production of economically important species of marine fish has been accelerated in Japan. Howecer, mass mortalities due to viral infections as well as other microbial infections have often occurred during the seed production and grow-out stages. Among these diseases, four viral diseases have been known in cultured Japanese flounder (Paralichthys olivaceus) since around 1980. In this paper, viral diseases of cultured flounder in Japan are briefly reviewed, with special attention to two viral diseases. viral epidermal hyperplasia and rhabdovirus infection which are relatively important because of their frequent occurrence. Viral epidermal hyperplasia is characterized by fin opacity and associated with high mortality in larval flounder Electron microscopy of affected epidermal cells and transmission experiments with tissue filtrates demonstrated that the disease was caused by a herpesvirus but the agent has not been isolated in fish cell lines. On the other hand, rhabdovires infection occurrs in juvenile and production size fish with hemorrhage in the skeltal muscle and fins, congestion of the gonads, and ascites. A rhabdovirys was isolated in RTG-2 cells from the diseased flounder as a causative agent, which was designated hirame rhabdovirus (HRV) or Rahbdovirus olivaceus. HRV is serologically distinguishable from other known fish rhabdoviruses. Intensive researches on these viral diseases started in 1980th. but properties of the causative agents and infection mechanisms have not been fully investigated. This results in difficulty in controlling these diseases.

• 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.17-23
• /
• 2024

Spring viremia of carp virus (SVCV) poses a significant threat to numerous cyprinid fish species, particularly the common carp (Cyprinus carpio), often resulting in substantial mortalities. This study explores the potential use of a chimeric recombinant snakehead rhabdovirus carrying the SVCV G gene (rSHRV-Gsvcv) as a live vaccine against SVCV infection. Through virulence testing in zebrafish at different temperatures (15 ℃ and 20 ℃), no mortality was observed in groups infected with either rSHRV-wild or chimeric rSHRV-Gsvcv at both temperatures, whereas 100% mortality occurred in fish infected with wild-type SVCV. Subsequently, as no mortality was observed by rSHRV-Gsvcv, three independent experiments were conducted to determine the possible usage of chimeric rSHRV-Gsvcv as a vaccine candidate against SVCV infection. Fish were immunized with either rSHRV-Gsvcv or rSHRV-wild, and their survival rates against the SVCV challenge were compared with a control group injected with buffer alone at four weeks post-immunization. The results showed that chimeric rSHRV-Gsvcv induced significantly higher fish survival rates compared to rSHRV-wild and the control groups. These findings suggest that genetically engineered chimeric rSHRV-Gsvcv holds the potential for a prophylactic measure to protect fish against SVCV infection.

• Journal of fish pathology
• /
• v.10 no.2
• /
• pp.165-176
• /
• 1997

Water samples collected from marine fish culture system in Korea were compared for their capability to reduce the infectivity titers of HRV (rhabdovirus olivaceus), FBV(flounder birnavirus) and RVS(retrovirus of salmonid). In addition, interaction between viruses and microorganisms present in the rearing seawater was examined. The titer of HRV and RVS were reduced at $15^{\circ}C$ to less than detectable limits within 3 to 5 days using untreated samples of seawater. No reduction of infectivity was noted in bacteria-free water treated by filtration or autoclaving. Bacteria (Pseudomonas and Vibrio sp.) isolated from the water collected from a flounder culture system showed the inactivation activity of HRV.

• Journal of Microbiology
• /
• v.40 no.4
• /
• pp.295-300
• /
• 2002

Previously, we reported induced expression of developmentally regulated CTP-binding protein 2 (DRG2) in fish cells at the late stage of rhabdovirus infection. To investigate the biological role of fish DRG2 (fDRG2), we transfected CHSE-214 cells with an expression vector containing complete fDRG2 fused to the N-terminal end of an enhanced green fluorescent protein (EGFP). Low level expression of fDRG2-EGFP did not induce morphological change or cell death. However, a high level expression of fDRG2-EGFP induced cell rounding and caused depletion of the cell population in FACS analysis. Several truncated fragments were fused to EGFP. FACS analysis was conducted to determine the presence of cells expressing high levels of the resulting chimera. While cells expressing a high level of N-terminus were detected, those expressing high levels of the C-terminal fragment 243-290 containing the G4 motif were absent in FACS analysis. Based on these observations, we propose that overexpression of fDRG2 may induce cell rounding, a representative cytopathic effect of virus-infected cells in the late stage of infection and the C-terminus of the fDRG2 is essential for this function.

• 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.21 no.3
• /
• pp.181-188
• /
• 2008

Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay was used to detect and identify four fish viruses, fish iridovirus, viral hemorrhagic septicaemia virus (VHSV), viral nervous necrosis virus (VNNV), hirame rhabdovirus (HRV). Four viruses were detected by PCR with each specific primers. Identification of iridovirus was achieved by digesting the PCR amplified fragment with a restriction enzyme ApaⅠ. It was possible to distinguish positive from false positive PCR amplicons of VHSV by RFLP of PstⅠ or HindⅢ restriction enzymes. VNNV was identified using RFLP of BamHⅠrestriction enzyme and HRV was identified by XbaⅠ restriction enzyme. This approach can be used for more rapid, simple and specific diagnosis of fish viral diseases.

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