• Korean Journal of Veterinary Research
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• v.48 no.3
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• pp.287-293
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• 2008

The cDNA of the aquabirnavirus, GC-1 isolated from rockfish Sebastes schlegeli in Korea, was synthesized using the reverse transcriptase-polymerase chain reaction. The nucleotide and deduced amino acid sequences were determined from cDNA of the VP2-NS-VP3 coding region of genome segment A. The nucleotide sequences of the segment A were 3,086 base pairs (bp) in length and contained large open reading frame (ORF) and terminal sequences. The large ORF was comprised of 2,916 bp nucleotides and composed of 972 deduced amino acid sequences. Pairwise comparisons were made with other aquabirnavirus sequences published previously. The study of genetic relationships between GC-1 and aquabirnaviruses in the large ORF and VP2 coding regions demonstrated that the GC-1 has the nearest genetic relationship with the marine birnaviruses (MABV strains), and the GC-1 and MABV strains can be clustered as the same genogroup. GC-1 can be included in MABV, which is the 7th genogroup of family Aquabirnaviridae.

• Journal of fish pathology
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• v.22 no.3
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• pp.211-218
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• 2009

In this study, we have compared the genome of marine birnavirus (MABV) detected from starry flounder Platichthys stellatus and olive flounder Paralichthys olivaceus. A molecular analysis based on the nucleotide sequence (433 bases) of VP2-NS-VP3 region revealed that MABV (08-KU) from starry flounder showed 98% similarity with MABV Y6 isolated from Yellowtail Seriola quinqueradita in Japan (Accession no: AY283781) and with other aquabirnaviruses identify more than 76%. Comparison with MABV strains (06-KP, 08-KC) from olive flounder and MABV Y6 strain showed 97-98% sequence identities. Phylogenetic analysis was performed in order to examine the relationship among previously determined aquatic birnaviruses isolates showed that MABV and IPNV strains were classified into seven clusters. Three isolates from starry flounder and olive flounder in this study, belong to the genogroup VII including MABV Y6 strain and other aquabirnaviruses isolated from marine fish and molluscan shellfish in Japan. This report is the first description of a MABV from starry flounder in Korea.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.5
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• pp.556-561
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• 2014

We applied a combination of most probable number-polymerase chain reaction (MPN-PCR) methods using a PCR procedure targeting the H-NS (VP1133) gene to detect Vibrio parahaemolyticus presence and density in seawater as well as within short-necked clam Ruditapes philippinarum tissues collected from Gomso Bay, Korea. In 30 seawater samples, V. parahaemolyticus levels ranged from less than 1.8 to $1.1{\times}10^3MPN/100mL$, and samples from August showed higher than those from other months. Furthermore, the levels of V. parahaemolyticus in six short-necked clam samples ranged from $7.8{\times}10^2$ to $2.1{\times}10^3MPN/100g$, approximately 2.5 times higher than in seawater samples from the corresponding month. Our results provide data on V. parahaemolyticus contamination in seawater and short-necked clam tissues, and help to improve quantitative methods of assessing V. parahaemolytcius levels.

• 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.