• Journal of fish pathology
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• v.15 no.1
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• pp.9-16
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• 2002

The objective of the study was to clarify the mechanism of persistent infection of marine birnavirus (MABV) in various nonpermissive cell lines. It was observed in CHSE-214, RTG-2 and RSBK-2 that the virus produced at high yield with typical cytopathic effect (CPE). On the contrary, the CPE was not produced in EPC, FHM and BF-2 cells. However amount of virus protein in both permissive and nonpermissive cell lines detected by ELISA was almost the same. Electron microscopy showed virions in permissive cells but not in nonpermissive cells. From the results, it is clear that virus protein and RNA were produced in nonpermissive cells as observed in permissive cells; however, assembly of the virus particles did not occur in nonpermissive cells.

• Korean Journal of Microbiology
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• v.22 no.2
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• pp.85-90
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• 1984

Two viruses were isolated from kidney and spleen tissues of goldfish(Carasius auratus) and the ovarian fluid of chum salmon(Oncorhynchus keta). Both viruses replicated and produced cytopathic effect in EPC, CHSE-214, and CHH-1 cell lines at $15^{\circ}C$. The isolates were resistant to pH 3 and choloroform. Antiserum to infections pancreatic necrosis virus(IPNV) serotype VR 299 neutralized the infectivity of both of the isolates. Electron microscopy showed that the particles had typical IPNV particle morphology with average diameters of 55nm, This paper describes the first isolation of viruses infecting cultured fish in Korea.

• Journal of fish pathology
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• v.4 no.2
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• pp.87-94
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• 1991

In the late summer of 1990 and 1991, mass mortality occured among cage-cultured grouper, Epinephelus septemfasciatus in south cost of Korea. The moribund fish didn't feed and became pale or dark chestnut colour and irregularly swimmed due to the loss of equilibrium, finally the diseased fish fell down side away on the bottom or the surface of cage showing the bent of body and died. The diseased fish showed the extensive hemorrahge in brain, the swelling of spleen and bile duct as the specific syptoms of internal organs. So the gill, skin and other organs of the diseased fish were examined for the presence of pathogenic parasites and bacteria. The parasitic Trichodina sp. were detected only from the gill lamella of the diseased fish, but these parasites seemed to be not a direct causative agents that induced the gross mortality of the cultured grouper. because these parasites were also observed in normal grouper, yellowtail, red seabream and rock bream co-cultured with the diseased grouper in same or near cages. In the viral examination, although isolation of the causative agent by the use of estabilshed cell Lines, RTG-2 and CHSE-214, was not succeed, the normal grouper inoculated intramuscularly with the filtered homogenate of the organs of the diseased fish showed the same external and internal signs with the naturally infected grouper. They died within a week. By using the naturally and the artificially infected fishes, electron microscopic observation revealed numerous hexagonal or polygonal particles in the cytoplasm of liver cells. Based on the these results, we suggest that the mass mortality of the cultured grouper would be occurred by the infection of a viral agent.

• Journal of fish pathology
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• v.6 no.2
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• pp.87-92
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• 1993

In February of 1990, an epizootic disease to masu salmon. Onchorynchus masou cultured at the hatchery of trout in Samchuk. Kwangwondo have broken out and induced heavy mortality. An infectious hematopoietic necrosis virus(IHNV) was isolated from diseased masu salmon fry by the use of fish cell line, CHSE-214. This IHNV isolated from masu salmon was compared with USA isolates of IHNV, SRCV and RB-76 by analysis of virion proteins in sodium dodecyl sulfate poly-acrylamide gel electrophoresis (SDS-PAGE) and neutralization tests with two monoclonal antibodies raised against SRCV(MAb SRCV/A4) and RB-76(MAb RB/B5). In the antigenicity and the size of structural proteins. this IHNV, SCS atrain was smilar to RB-76 belonged to the electropherotype I proposed by Hsu et al.(1986).

• Journal of Microbiology
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• v.34 no.2
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• pp.124-130
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• 1996

A survey was conducted to determine the prevalance of infectious pancreatic necrosis virus (IPNV) on fish farms in Korea and the epidemiology of IPNV infection in the farmed rainbow trout. In total, 43 pools of rainbow trout with apparent signs of viral infection from five provinces were obtained and analyzed. Evident cytopathic effects, including karyopycnosis and cell destruction, were observed in CHSE (chinook samlmon embyro)-214 cells infected with the virus isolates. Of these, ten viral isolates were assumed to be IPNV based on biophysical properties. RNA analysis revealed that the isolates contained two-segmented RNA genomes, further indicating that the viral isolates are IPNV. Antigenic comparison of the IPNV isolates identified three distinct serological groups separable by the cross-neutralization test. Of the ten IPNV isolates, six could be classified as strain DRT, two as strain Ab, and two as strain VR299. We were not able to isolate new strain of IPNV or any isolate serologically similar to the standard strain Sp.poraceae and families of the Agaricales, they are genetically more related to the Polyporaceae. These results are consistent with morphological characters observed in those mushrooms. However, it is premature to conclude taxonomic status Ganoderma species in the present study employing small sample size.

• Journal of fish pathology
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• v.12 no.1
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• pp.49-55
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• 1999

To detect birnavirus from cultured marine fish, RT-PCR assay was developed. This method was specific for aquatic birnaviruses that include IPNV Sp., IPNV Ab, IPNV VR-299 and MBV Y6. The birnavirus gene was detected (birnavirus positive samples detected 46/50) from clinical samples signed with abdominal distension and overall darkening even though the samples gave negative results in virus isolation (birnavirus isolate with CHSE-214 cell showed 12/50).

• Journal of fish pathology
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• v.24 no.3
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• pp.213-223
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• 2011

Among wild marbled sole, Pleuronectes yokohamae caught in west coastal area, Chungnam, tumor-bearing fish were found. Parasites and pathogenic bacteria were not detected and CPE was not observed. Using the light microscope, the epidermal layer of wild P. yokohamae was significantly thickened compared to the normal skin. The lesion was formed papillary folds. Hypertropical epithelial cells revealed karyolysis, marked nucleolus and cloud swelled cytoplasm. In the epidermal layer of the lesion, X-cell that is characterized by oval and small pale nucleus and prominent nucleolus was observed. Dermal layer had newly formed vessels. The size of mucous cell in the papilloma lesion was significantly increased compared to the normal. In this study, no pathogens were found, so future works for finding cause of the papilloma in the P. yokohamae are needed.

• Journal of fish pathology
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• v.30 no.2
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• pp.71-78
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• 2017

The glycoprotein of novirhabdoviruses is known to play a critical role in the determination of host specificity. Viral hemorrhagic septicemia viruses (VHSVs) in different genotypes have different glycoprotein sequences and show different preferences for specific cell lines. In this study, to know whether the glycoprotein is solely responsible for the host cell preference of VHSV, a recombinant VHSV expressing vesicular stomatitis virus (VSV) glycoprotein instead of VHSV IVa glycoprotein (rVHSV-VSV-G) was generated by reverse genetics and inoculated into several fish cell lines, then, cytopathic effect (CPE) and viral growth caused by rVHSV-VSV-G infection were compared with those caused by rVHSV-wild that was previously generated and has the same genomic sequence with wild-type VHSV except a few nucleotides. The plaque numbers of rVHSV-VSV-G were significantly higher in EPC, BF-2 and GF cells than those of rVHSV-wild. However, in HINAE cells (originated from olive flounder), rVHSV-VSV-G titer was significantly lower than rVHSV-wild titer, and both recombinant VHSVs were not grown well in CHSE-214 cells. Although statistical significances were detected in the titers between rVHSV-wild and rVHSV-VSV-G in several cell lines, the cell line-preference order of rVHSV-VSV-G was not different from that of rVHSV-wild. These results suggest that the replacement of VHSV glycoprotein may not completely change host cell preference, and other regions of VHSV might also involve in the determination of host cell preference.

• Journal of fish pathology
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• v.22 no.3
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• pp.229-237
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• 2009

The causative agent for the tunic softness syndrome of the cultured ascidian Halocynthia roretzi from Jan 1999 to Feb 2009 was identified using virus isolation and polymerase chain reaction (PCR). The pathogenicity of the isolated virus MABV UR-1 strain was determined by experimental infection trials. The cytopathic effects was observed in CHSE-214 cell line at a level 5.1% (4/78) in normal ascidian and 1.8% in abnormal ascidian showing tunic softness syndrome signs. MABV gene was detected in 16.8% (18/107) of normal and 13.1% (5/38) of abnormal organisms by PCR. The ratio of MABV isolation and gene detection was similar level in normal and soft tunic diseased ascidian. Based on the VP2/NS junction region sequences, eight strains of virus isolated from ascidian, were included in the same genogroup with MABV which is originally isolated in wide ranges of marine fish and shellfish species. The UR-1 strain caused 60% mortality (36.5% mortality in control group) by immersion infection and 37% mortality (same mortality in control group) in injection infection indicating no significant differences in infected and control groups. These results suggest that ascidian can act as reservoir of the MABV, and this virus is not directly related with the ascidian mortality.

• Journal of fish pathology
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• v.13 no.1
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• pp.53-59
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• 2000

Presence of marine birnavirus (MABV) was examined against egg and ovarian fluid, and seminal fluid from the brood stocks of flounder, Paralichthys olivaceus collected from 9 different stations around Korean peninsula. The detection rate of MABV in brood stocks flounder was observed to 34% by PCR. The mean virus titer of the PCR positive fish was $10^{2.30}$ to $10^{4.30}$ $TCID_{50}$/g(ml). By a neutralization test, all of the isolated virus were ascertained to be closely related to marine birnavirus (MABV).