• Journal of fish pathology
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• v.28 no.3
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• pp.133-143
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• 2015

The antigenic proteins of Lymphocystis disease virus (LCDV) from tumors of olive flounder, Paralichthys olivaceus, are described following characterization by mass spectrometry. In SDS-PAGE, predominant protein bands were observed at 114, 88, 70, 54, 52, 47, 42 and 24 kDa. Western blot analysis showed that antisera reacted strongly at molecular weights of 114, 67 and 54 kDa, and reacted weakly at molecular weights of 74, 70, 36, 24 and 22 kDa. In the identification of LCDV antigenic proteins by matrix-assisted laser desorption ionization (MALDI) TOF mass spectrometry, 10 of 14 excised bands consisted mostly of proteins with amino acid sequences that matched LCDV-C (lymphocystis disease virus isolate China) ORFs. Strong antigens with molecular weights of 114, 67 and 54 kDa were identified as LDVICp236 (chromosome segregation ATPase), LDVICp033 (membrane bound metallopeptidase) and LDVICp157 (hypothetical protein), respectively. Minor antigens with molecular weights of 70, 36, 24 and 22 kDa proteins were identified as LDVICp160 (acetyl-coA hydrolase), LDVICp213 (hypothetical protein), LDVICp039 (hypothetical protein) and LDVICp213 (hypothetical protein). However, the major capsid protein (LDVICp043) did not react with the polyclonal antibody.

• Journal of Fisheries and Marine Sciences Education
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• v.27 no.6
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• pp.1656-1664
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• 2015

The effects of lightyellow sophora, Sophora flavescens extract were tested on non-specific immune response and a disease resistance of olive flounder, Paralichthys olivaceus. For feeding trial, weight gain of fish fed different treated groups were not significant differences. Serum analysis of treated and control group did not demonstrated any differences. Lysozyme activity in the kidney and spleen of the 0.05% treated group on $4^{th}$ and $8^{th}$ week showed significant increase, respectively. In addition, phagocytic activity of the 0.05% treated group on $4^{th}$ and 8th week showed significant increase compared to the control group. Histopathology of the liver and kidney tissue of the administrated group for $4^{th}$, $8^{th}$ and $12^{th}$ week showed no particular signs of tissue degeneration. The treated group was higher than control group by analyzing the relative percent survival (RPS) of the experimental challenge of Edwardsiella tarda. Therefore, the lightyellow sophora showed effective in preventing fish-pathogenic edwardsiellosis for a certain period of time.

• Journal of fish pathology
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• v.25 no.3
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• pp.231-241
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• 2012

Diagnostic monitoring in fish farms with land-based tanks and netpen cases were conducted in eastern, western, southern and Jeju island of Korea during summer of 2007~2011. In total, 2413-fish samples of 4 marine fish species were tested for the detection of bacteria and parasite. Fish species tested were olive flounder (Paralichthys olivaceus), black rockfish (Sebastes schlegeli), red sea bream (Pagrus major), pacific white shrimp (Litopenaeus vannamei). During the diagnostic monitoring from 2007 to 2011, the infection rates by single infection of bacterial or parasitic pathogens were relatively higher than the mixed infections. The main bacterial pathogens in olive flounder, black rockfish and pacific white shrimp were Vibrio spp. (V. harveyi, V. ichthyoenteri, Vibrio sp.). The main bacterial pathogens in red sea bream were also Vibrio sp. and Photobacterium damselae subsp. damselae. The main parasitic pathogens were both Miamiensis avidus and Trichodina sp. in olive flounder, Microcotyle sebastes in black rockfish, Microcotyle tai in red sea bream and Zoothamnium sp. in pacific white shrimp.

• Journal of fish pathology
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• v.22 no.2
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• pp.173-177
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• 2009

Lymphocystis disease virus (LCDV) was detected from olive flounder Paralichthys olivaceus, painted glass fish Chanda baculis, gourami Trichogaster leeri and rockfish Sebastes schlegeli, and proteins of the viruses were compared. The major capsid protein (MCP) gene-specific primer sets successfully amplified approximately 1300 bp nucleotides from the olive flounder and 600 bp nucleotides from painted glass fish, gourami and rockfish isolates, respectively. In western blotting analysis using anti-LCDV mouse polyclonal serum, major antigenic proteins had 21, 26, 45, 50, 80, 110 and 120 kDa in olive flounder, 26, 47 and 80 kDa in painted glass fish, 26, 46, 80 and 92 kDa in gourami, 26, 44, 49, 80 and 105 in rockfish, respectively. All the marine and freshwater isolates showed only common antigens of approximately 26 kDa and 80 kDa. These results suggest that antigenic protein profiles of LCDVs may vary depending upon fish species.

• Fisheries and Aquatic Sciences
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• v.9 no.3
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• pp.123-128
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• 2006

An epizootic causing mortality among cultured marine finfishes occurred in 1999 in the province of Kyoungsang, Korea. The disease was characterized by the presence of enterocele, abdominal swelling, and gastroenteritis. The causative bacteria were isolated from olive flounder (Paralichthys olivaceus), black rockfish (Sebastes schlegeli), turbot (Scophthalmus maximus) and the rearing water. These bacteria showed swarming activity on agar plates and yellowish or greenish colonies on thiosulfate-citrate-bile salts-sucrose (TCBS) agar plates, but no luminescence. The pathogen was identified as Vibrio harveyi based on morphological and biochemical characteristics and the sequence of l6S rDNA. The lethal doses (LD$_{50}$) of olive flounder and black rockfish were estimated to be $1.24\times10^6-1.36\times10^8$ and $3.24\times10^5-5.8\times10^7$ CFU/fish respectively following intraperitoneal injection.

• Journal of fish pathology
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• v.30 no.1
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• pp.67-70
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• 2017

Pseudomonas is currently causing increasing mortality in farmed olive flounder in Jeju Island. It was previously reported that P. anguilliseptica is the pathogen causing the mortality. It is not known whether other sub-species are involved or not. In this study, P. fluorescens was identified from diseased olive flounder by a PCR-based diagnosis. Based on genomic sequencing and BLAST analysis, 5 out of 6 samples were closer with P. fluorescens than P. anguilliseptica. Our finding suggests that P. fluorescens may be the dominant species causing the disease in farmed olive flounder in Jeju Island, South Korea.

• Journal of fish pathology
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• v.19 no.2
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• pp.127-139
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• 2006

From 2002 to 2004, various vibrios were isolated from the olive flounder, Paralichthys olivaceus of culturing size with disease signs. During this survey, it was known that the high proportion of Vibrio ichthyoenteri was occupied among the isolated vibrios. Generally, V. ichthyoenteri is well known as the pathogen of bacterial enteritis of olive flounder larvae. The aim of the present study was the compare the characteristics of two groups of V. ichthyoenteri, culturing sized olive flounder, and larvae of olive flounder showing the intestinal necrosis. The research was focused on the physiology, biochemistry, genetics in the two bacterial groups. The physiological and biochemical characteristics of the tested strains were very similar. The intergenic spacer (IGS) region between the 16S and 23S rRNA genes of 21 isolated strains and 3 reference strains, V. ichthyoenteri, were investigated by PCR fragment length typing and DNA sequencing. After the isolated strains were identified as V. ichthyoenteri, not only phenotypic characteristics of the isolated and reference strains but also homology of 16S-23S IGS of all isolated strains and reference strains as 99.1~100%. The V. ichthyoenteri showed 4 specific 16S-23S patterns and contained no-tRNA, tRNAGlu(TTC) , tRNAIle(GAT) tRNAAla(TGC) type .

• Korean Journal of Fisheries and Aquatic Sciences
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• v.52 no.5
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• pp.539-546
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• 2019

The major cultured marine fishes in sea off the coast Gyeongsangnam-do Province, South Korea, were assessed and included 9.3% rockfish Sebastes schlegelii, 7.8% red seabream Pagrus major, and 2.1% rock bream Oplegnathus fasciatus. The number of insurance payments related to disease mortality in cultured fish in 2017 was fourfold that in 2016. Economic loss in aquaculture due to disease in cultured fish is high and represents an important inhibitory factor affecting marine fishery productivity. In 2018, diseases led to severe production losses in several aquaculture species: 40.0% in rockfish, 11.4% in olive flounder Paralichthys olivaceus, 10.0% in filefish Thamnaconus modestus, and 9.3% in red seabream. Fish-parasitic pathogens such as Microcotyle sebastis, Alella spp., and Dactylogyrus spp. enter mainly via the gills and skin surface. Among bacterial pathogens, Vibrio species were most common, with Vibrio harveyi being the dominant species causing infections in these fishes. The bacterium Lactococcus garvieae is thought to exhibit host specificity in fish. The fish species in the present study exhibited a higher tendency for infection by heterologous pathogens than by a single pathogen; therefore, it is necessary to devise new strategies for treating diseases in cultured fish.

• Journal of fish pathology
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• v.4 no.2
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• pp.71-77
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• 1991

From August to October of 1991, a bacterial disease occurred in cultured flounder, of 0 age Paralichthys olivaceus, in Cheju-do. Typical symptoms of the diseased fish were the hemorrage of the opercle, discoloration of the body, exophthalmus and hemorrhage of the eyes. The causative organism isolated from diseased fish was identified as a $\beta$-hemolytic Streptococcus. This bacterium was not identical with any known Streptococcus species listed in Bergey's Manual of Determinative Bacteriology 8th edition. However there was a close similarity between this species and Streptococcus sp. isolated from flounder and reported by Tashio (1983). The isolated bacteria streptococcus sp. showed very high sensitivity to the SM and EM, however, it resisted to the high concentration of Penicillin. In the pathagenicity analysis, about $1.1{\times}10^9$, $1.1{\times}10^7$, $1.1{\times}10^5$, $1.1{\times}10^3$, $1.1{\times}10^1cells$/100g B.W of isolated bacteria were injected percutaneouly. The results showed that this inoculation size $1.1{\times}10^3cells$/100g B.W was the threshold for the induction of mortality in pathogenicity analysis.

• Fisheries and Aquatic Sciences
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• v.23 no.9
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• pp.26.1-26.9
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• 2020

Background: The study evaluated the effects of a butaphosphan and cyanocobalamin mixture on the immune system and stress in olive flounders, Paralichthys olivaceus. Methods: The mixture was intramuscularly injected into olive flounders at the current recommended dose. Furthermore, to determine the toxicity of overdose, a histological examination was performed after injection of 1-, 2-, and 4-fold higher than the recommended dose. Results: Immunity parameters were altered during the first 2 weeks after a single intramuscular injection of the mixture in olive flounders (average weight 20.5 ± 1.1 g). The levels of all tested items, except glutathione and antiprotease, were higher in the treated group than in the control group in the first week; the levels of all tested items were even higher in the second week in the treated group than in the control group. The level of nitro-blue tetrazolium, myeloperoxidase, and superoxide dismutase between the two groups differed significantly. Changes in the stress response to different seawater temperatures (increase or decrease in seawater temperature by 3-5 ℃ using 50 L heated or cooled seawater tanks) were studied by determining the changes in cortisol and glucose levels on days 1 and 7. Both cortisol and glucose levels were significantly lower in the treated group than in the control group. Histological analysis did not reveal any abnormalities after intramuscular injection of the mixture at doses that were 1-, 2-, and 4-fold higher than the recommended dose. Conclusions: Intramuscular injection of a butaphosphan and cyanocobalamin mixture is safe and effective in reducing stress and improving immunity in olive flounders.