• 한국어병학회지
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• 제27권1호
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• pp.11-16
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• 2014

The resistance against white spot syndrome virus (WSSV) infection in wild marine crab Gaetice depressus by the immunization of a recombinant glutathione-S-transferase (GST) fused VP28 protein (GST-VP28) was evaluated. The cumulative mortalities of GST-VP28 injected groups were lower than those of the control groups at 10 days of post-challenge, and the time to death of 50% crab ($TD_{50}$) was delayed by the immunization using GST-VP28. The group boosted with GST-VP28 after 2 weeks of primary immunization clearly showed longer $TD_{50}$ than non-boosted group against challenge with WSSV. This result suggests that boosting with the antigen protein elicit stronger immune responses similar to adaptive immune responses of vertebrates. However, the short $TD_{50}$ was observed in the group challenged at 3 weeks post boosting comparing to the group challenged at 1 week post boosting. This suggests that the protective strength of immunization decreased by the time.

• 한국어병학회지
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• 제34권2호
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• pp.177-184
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• 2021

Vaccines based on single-cycle viruses that are replication-incompetent due to knockout of replication-related structural gene(s) are more immunogenic than inactivated or subunit vaccines and can be used as delivery vehicles for foreign antigens without concerns on the reverting to virulent forms. The aim of this study was to develop a delivery vehicle for nervous necrosis virus (NNV)-like particles (VLPs) using G gene deleted single-cycle VHSV (rVHSV-𝚫G). Recombinant single-cycle VHSVs carrying NNV capsid protein gene between N and P gene of rVHSV-𝚫G genome (rVHSV-𝚫G-NNV_Cap) were rescued by reverse genetic technology. The successful expression of NNV capsid protein in cells infected with rVHSV-𝚫G-NNV_Cap was demonstrated by Western blot analysis, and the production of NNV VLPs in infected cells was confirmed using an electron microscopy. The results suggest that single-cycle VHSVs can be used as a safe delivery vehicle for NNV VLPs, and can be extended to other pathogens for the development of prophylactic vaccines.

• 한국어병학회지
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• 제33권2호
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• pp.139-143
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• 2020

This study investigated the disinfection effect of monopersulfate (MPS) compound against white spot syndrome virus (WSSV) by bioassay using kuruma shrimp (Marsupenaeus japonicas). A WSSV stock was prepared with muscle homogenate from WSSV-infected whiteleg shrimp (Penaeus vannamei) and its lethal dose 50% endpoint (LD50) and infectious dose 50% endpoint (SID50) were respectively determined as 10-5.63 and 10-6.79 in bioassay using kuruma shrimp, followed by PCR assays. The disinfective effect of MPS compound (1.2 ppm, 2.4 ppm, 4.8 ppm) was performed by bioassay using about 10-fold higher dilution (10-4) of WSSV homogenate. The compound resulted in WSSV inactivation by a concentration-dependent manner. In addition, 4.8 ppm of MPS completely prohibited WSSV infection. To our knowledge, this study is the first report about the usefulness of MPS as a disinfectant to WSSV.

• Fisheries and Aquatic Sciences
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• 제25권7호
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• pp.403-408
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• 2022

In April and June 2014, mortalities of goldfish occurred at Korea. The principal signs included pale gills, severely enlarged and softened spleen and kidney and red liver. Moreover, the histopathological characteristics observed mainly in hematopoietic tissues of kidney, gill lamellae and intestine. The predominant histopathological changes were severe necrosis of hematopoietic tissue. In addition, nucleus exhibiting peripherally displaced chromatin were particularly abundant in the kidney of affected fish. The histological examination led to hypothesize the implication of a virus in the mortality. The hematopoietic necrosis herpesvirus (Cyprinid herpesvirus 2, CyHV-2) DNA polymerase gene successfully detected in DNA extracted from kidney and spleen of affected fish using PCR assay and showed 100% identity with already deposited CyHV-2 DNA polymerase gene in NCBI. Artificial infection trials using affected tissues filtrates gave cumulative mortalities of 30% for virus injected goldfish. In the present study, CyHV-2 was detected and identified as the causative pathogen of the epizootic in goldfish in Korea.

• 한국어병학회지
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• 제35권1호
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• pp.129-133
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• 2022

The full genome sequence of a Korean white spot syndrome virus (WSSV, isolate: WSSV-GoC18) is presented here. We obtained a total of 12,320,554 reads with 291,172 bases, 170 gene, and 170 coding DNA sequence, which were assembled in 1 contig. Phylogenetic analysis revealed that the WSSV-GoC18 was closely related to Chinese isolate (WSSV-PC) and distinctly different with previously reported a Korean isolate (WSSV K-LV1). The complete genome sequence of WSSV isolates will be of great help in molecular epidemiological studies, contributing to molecular diagnosis and disease prevention in shrimp aquaculture.

• 한국어병학회지
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• 제17권3호
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• pp.213-216
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• 2004

To confirm the possibility of a wild marine crab, Gaetice depressus, as a carrier for white spot syndrome virus (WSSV) and to develop an alternative experimental model for WSSV in winter season, the susceptibility of the crab to WSSV was assessed by artificial challenge and subsequently tested for infection by PCR assay. The results revealed that the crabs were as highly susceptible as penaeid shrimps. WSSV caused 100% mortality in G. depressus within 16 days after intramuscular injection. The presence of WSSV in the moribund crabs was confirmed by PCR and was found in gills and muscle tissue. These results suggest that G. depressus can be naturally infected by WSSV via moribund shrimps, and can act as a potential carrier of WSSV. In addition, G. depressus can be used as an alternative experimental animal for WSSV.

• 한국어병학회지
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• 제16권3호
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• pp.161-164
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• 2003

An Infectious hematopoietic necrosis virus strain (IHNV-RTK) was isolated from cultured rainbow trout at Kumi and Jechun area in Korea during 2000 and 2001. In the RT-PCR amplification with the specific primer set designed from IHNV G protein region, a 540 bp PCR product was amplified from the RTK strain. The RTK strain showed higher sequence homology with the published IHNV G protein genes (RB-76, LR-73, Col-85, and Carson-89)

• 한국수산과학회지
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• 제48권4호
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• pp.403-410
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• 2015

Viral nervous necrosis (VNN) is a serious disease of sevenband grouper Epinephelus septemfasciatus in Korean aquaculture farms. However, we suggest the following preventative methods for hatcheries: 1) disinfecting rearing water, 2) selecting spawners via ELISA and PCR, 3) selecting eggs via PCR, 4) disinfecting fertilized eggs, and 5) proper facilities management. When these methods are implemented, nervous necrosis virus (NNV)-free fish are produced because vertical and horizontal transmission is prevented. However, horizontal transmission of NNV through rearing seawater sourced from the environment during grow-out stages in sea cages can still occur. Live NNV vaccines with a low rearing temperature or Poly(I:C) immunization are very effective at preventing horizontal transmission of NNV in rearing farms. Furthermore, even after VNN is contracted, fish mortality can be reduced by administering Poly(I:C).

• 한국어병학회지
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• 제26권3호
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• pp.149-161
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• 2013

바이러스성 출혈성 패혈증을 일으키는 VHSV는 국내의 넙치양식에 심각한 피해를 주고 있다. 본 연구에서는 우리나라에서 분리한 8종의 VHSV 분리주들의 glycoprotein (G)의 염기서열을 분석하여 Korean VHSV 분리주들과 기보고된 일본 및 중국의 분리주들을 계통발생학적으로 비교하여 G-protein의 8 부위(G34, C528, A755, T834, T951, T1147, T1221, T1336)에서 국내 VHSV 분리주들의 특이적인 서열을 확인하였고, 전 세계적으로 분리된 VHSV의 분리주들과의 비교결과 8 부위 중 3 부위 (A755, T834, T1221)의 국내VHSV 분리주 특이적 염기서열들을 확인하였다. 또한 중국 유래 VHSV 분리주의 특이적 염기서열 11 부위 (C498, C545, C548, C642, G648, T678, A738, C804, C834, G851, C1139)와 일본 유래 VHSV 분리주의 특이적 염기서열 1부위 (C179)를 확인하였다. 이상의 연구결과는 국내 특이적인 염기서열을 확보하여, 구역화된 수산생물 질병의 예찰, 모니터링 및 질병 관리에 유용하게 사용될 것으로 사료된다.

• 한국어병학회지
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• 제31권1호
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• pp.9-13
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• 2018

2017년 1월에서 4월까지 강원도 고성에서 사육중인 명태 친어로부터 수정란을 채집하여 신경괴사증바이러스(nervous necrosis virus, NNV)의 검출을 시도하였다. 매 회 50 mg씩 수정란을 채집하여 이를 1 set로 간주하였으며 총 37 set를 제작하였다. RNA를 추출하고 cDNA를 합성하여 NNV를 대상으로 reverse transcriptase PCR을 실시하였다. 그 결과, one-step PCR법으로는 37 set의 시료가 모두 음성이었으며, two-step PCR법으로는 5.4% (2/37)의 시료가 양성을 나타내었다. 그러나, band의 농도가 매우 낮아 시퀀싱은 불가능하였다. 본 연구의 결과 및 이전 연구의 결과로부터 현재 국내에서 양식하고 있는 명태에서 NNV 감염에 의한 폐사는 발생하지 않는 것으로 추정된다. 하지만, 지속적인 모니터링 및 양성 개체 출현 시 바이러스 분리의 시도 등은 필요할 것으로 생각된다.