• 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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• 제25권2호
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• pp.111-116
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• 2012

본 연구에서는 2006-2008년 남해안 일대의 해상가두리에서 사육중인 능성어에서 발생하는 viral nervous necrosis (VNN)의 발생양상을 조사하였다. VNN은 사육 수온이 $24-26^{\circ}C$ 범위인 8월부터 발생하기 시작하여 수온이 $20-25^{\circ}C$ 범위인 9-10월까지 지속되었고, 성어보다는 치어에서 폐사율이 높게 나타나는 것으로 확인되었다. 폐사되는 패턴으로는 급성으로 인한 대량폐사와 소량으로 지속적으로 폐사되는 경우가 확인되었다. 능성어로부터 분리된 NNV 분리주들의 coat protein gene을 계통분석한 결과, 분리주들은 모두 RGNNV 유전자형에 속하였다. 이상의 결과로 능성어 양식장에서의 VNN은 RGNNV type의 NNV에 의해 여름철 7-9월(사육수온: 약 $24^{\circ}C$)에 치어뿐만 아니라 성어에서 발생하는 것으로 확인되었다.

• Journal of Microbiology and Biotechnology
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• 제25권10호
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• pp.1761-1767
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• 2015

Sevenband grouper, Epinephelus septemfasciatus, is becoming an important aquaculture species in Korea. However, viral nervous necrosis disease is a large problem causing mass mortality in sevenband grouper aquaculture. Recombinant protein vaccines are one of the best methods to reduce these economic losses. However, the cell-based expression method mainly produces inclusion bodies and requires additional procedures. In this study, we expressed a recombinant viral coat protein of sevenband grouper nervous necrosis virus (NNV) using a cell-free protein synthesis system. The purified recombinant NNV coat protein (rNNV-CP) was injected into sevenband grouper at different doses followed by a NNV challenge. Nonimmunized fish in the first trial (20 μg/fish) began to die 5 days post-challenge and reached 70% cumulative mortality. In contrast, immunized fish also starting dying 5 days postchallenge but lower cumulative mortality (10%) was observed. Cumulative morality in the second trial with different doses (20, 4, and 0.8 μg/fish) was 10%, 40%, and 50%, respectively. These results suggest that rNNV-CP can effectively immunize sevenband grouper depending on the dose administered. This study provides a new approach to develop a recombinant vaccine against NNV infection for sevenband grouper.

• 한국어업기술학회:학술대회논문집
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• 한국어업기술학회 2001년도 춘계 수산관련학회 공동학술대회발표요지집
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• pp.511-512
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• 2001

VNN(viral nervous necrosis)는 종묘단계 및 양성장의 해산어 양식장에서 발생하는 바이러스성 질병으로 외견적으로 척추만곡, 이상유영, 체색흑화와 조직학적으로는 뇌와 망막에 공포 및 괴사를 형성하고, 또한 매우 높은 폐사율을 나타내는 질병으로 보고되어 있다. 이러한 질병은 성공적인 종묘의 생산 및 보급을 위해서 반드시 해결해야 할 사항이다. (중략)

• 한국어병학회지
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• 제14권2호
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• pp.91-95
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• 2001

1999년 10월에서 11월 사이에 남해안 일대의 홍민어 종묘 생산장에서 20~30열령의 치어가 척추만곡 및 이상유영을 하며 대량 폐사하였다. 병어는 특이 외부 증상이 없었고, 높은 누적폐사량이 바이러스 질병으로 의심되어, 조직학적 및 분자생물학적인 검사를 행하여 폐사원인을 확인하였다. 폐사개체의 조직을 H-E 염색하여 관찰한 결과 뇌와 안구의 신경세포에서 공포와 괴사가 관찰되었고, 전자현미경 관찰에서는 안구와 뇌에서 바이러스 입자가 관찰되었다. RT-PCR 결과에서는 ${\fallingdotseq}426$ bp의 DNA 단편을 확인할 수 있었다. 이러한 결과로 홍민어에서 발생한 대량폐사는 바이러스성 신경괴사증(VNN)으로 진단되었다.

• 한국수산과학회지
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• 제51권3호
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• pp.328-331
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• 2018

We developed and subsequently characterized mouse monoclonal antibodies (MAbs) against nervous necrosis virus (NNV, RGNNV genotype). We established six hybridoma clones secreting MAbs against NNV antigen: 2B1, 2B11, 2C12, 13C1-1, 13C1-2 and 14D11. All six MAbs belonged to the IgG2a isotype with a kappa light chain and their reactivity recognized against the 41 kDa coat protein of NNV by Western blot analysis. The affinity constants of the six MAbs were measured by enzyme-linked immunosorbent assay (ELISA). All six MAbs reacted with two NNV isolates (SgNag05 and Gemunodo06), while no reactivity was observed with five know fish viruses, namely marine birnavirus, infectious pancreatic necrosis virus, viral hemorrhagic septicemia virus, hirame rhabdovirus, and infectious hematopoietic necrosis virus. Moreover, high ELISA optical density (OD) values (0.87-1.42) were observed in the brain tissues of NNV-infected sevenband grouper, while low OD values (less than 0.12) were recorded in the brain tissues of uninfected fish. These results suggest that these six MAbs are highly competent and useful for the detection of NNV with the RGNNV genotype.

• 한국어병학회지
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• 제33권2호
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• pp.103-109
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• 2020

In order to use nervous necrosis virus (NNV) virus-like particles (VLPs) as a delivery tool for heterologous antigens or plasmids, we attempted to produce red-spotted grouper nervous necrosis virus (RGNNV) VLPs displaying a partial region of viral hemorrhagic septicemia virus (VHSV) glycoprotein at the surface and VLPs that are harboring DNA vaccine plasmids within the VLP. A peptide encoding 105 amino acids of VHSV glycoprotein was genetically inserted in the loop region of NNV capsid gene, and VLPs expressing the partial part of VHSV glycoprotein were successfully produced. However, in the transmission electron microscope analysis, the shape and size of the partial VHSV glycoprotein-expressing NNV VLPs were irregular and variable, respectively, indicating that the normal assembly of capsid proteins was inhibited by the relatively long foreign peptide (105 aa) on the loop region. To encapsulate by simultaneous transformation with both NNV capsid gene expressing plasmids and DNA vaccine plasmids (having an eGFP expressing cassette under the CMV promoter), NNV VLPs containing plasmids were produced. The encapsulation of plasmids in the NNV VLPs was demonstrated by PCR and cells exposed to the VLPs encapsulating DNA vaccine plasmids showed fluorescence. These results suggest that the encapsulation of plasmids in NNV VLPs can be done with a simple one-step process, excluding the process of disassembly-reassembly of VLPs, and NNV VLPs can be used as a delivery tool for DNA vaccine vectors.

• 한국어병학회지
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• 제30권2호
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• pp.149-154
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• 2017

Mouse monoclonal antibodies (MAbs) were produced by using viral hemorrhagic septicemia virus (VHSV, genotype IVa) as an immunogen, isolated from diseased olive flounder (Paralichthys olivaceus). Four hybridoma clones secreting MAbs against VHSV were established. The MAbs were recognized the nucleoprotein (MAb 4), phosphoprotein (MAb 1) and matrix protein (MAbs 2 and 3) of VHSV by western blot analysis. Among them, the MAbs 1 and 4 strongly reacted with the VHSV-infected FHM cells, but not normal FHM cells. In enzyme linked immunosorbent assay, the four MAbs reacted with the VHSV, but not different six fish viruses (infectious hematopoietic necrosis virus, hirame rhabdovirus, spring viraemia of carp virus, infectious pancreatic necrosis virus, marine birnavirus and nervous necrosis virus). These results indicate that the MAbs are useful for diagnosis of VHSV infection.

• 대한수의학회지
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• 제28권2호
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• pp.371-377
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• 1988

In order to know the effect of dexamethasone on the induction of the rabbit viral hepatitis, the pathological changes were observed in the native rabbits, 2 to 6 months old in age, that were injected by dexamethasone and liver emulsion of Angora rabbit naturally infected with viral hepatitis. The results were summarized as follows: The native rabbits injected by dexamethasone and liver emulsion were infected with viral hepatitis and died between 2 and 7 days after inoculation. Clinical signs and gross lesions were very similar to those of Angora rabbit naturally occurred, In microscopical findings, the hepatic lesions were characterized by peripheral necrosis of the lobules, and peripheral necrosis of the lobules with fatty changes of hepatic cells was occurred in a few cases. Perivascular lymphocytic infiltration in the central nervous system was observed in some cases, The lesions of the other organs were very similar to those of Angora rabbit naturally occurred. On the other hand, the native rabbits that were injected by only liver emulsion of Angora rabbit naturally infected with viral hepatitis were not infected with the disease except very few cases.

• 한국어병학회지
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• 제12권2호
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• pp.107-113
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• 1999

능성어의 바이러스성 신경괴사증 바이러스(fish nodavirus)의 병원성을 능성어 및 다른 해산어류를 대상으로 인위감염법에 의해 조사한 결과, 능성어 바이러스성 신경괴사증 바이러스는 능성어에서는 소형어(27 g)부터 대형어(104 g)까지 제사를 일으켜 강한 병원성을 나타냈지만, 실험에 사용한 크기의 방어(537 g), 참돔(207 g), 돌돔(43 g), 넙치(41 g), 자주복(27 g) 및 조피볼락(94 g)에는 폐사를 일으키지 않아 병원성을 나타내지 않았다. 그리고 사육수온별 능성어에 대한 바이러스의 병원성은 수온 $15^{\circ}C$에서는 병원성을 나타내지 않았고, 수온 $20\sim28^{\circ}C$에서는 수온이 높을 수록 병원성을 강하게 나타냈다. 그리고 바이러스는 근육주사, 복강 주사 및 경구감염뿐만 아니라 침지감염과 혼합사육감염에 의해서도 쉽게 능성어에 감염이 되지만, 감염 후 생존한 능성어에 대해서는 바이러스를 재감염시켜도 폐사가 일어나지 않았다.