Genetic polymorphism of MHC class IIα alleles and its association with resistance/susceptibility to viral nervous necrosis virus (VNNV) in golden pompano (Trachinotus ovatus)

Aquaculture ◽  
2019 ◽  
Vol 501 ◽  
pp. 144-152
Author(s):  
Zhenjie Cao ◽  
Xiaocen Liu ◽  
Yajing Xiang ◽  
Lu Wang ◽  
Yun Sun ◽  
...  
Keyword(s):  
Genetic Polymorphism ◽  
Nervous Necrosis Virus ◽  
Necrosis Virus ◽  
Trachinotus Ovatus ◽  
Golden Pompano ◽  
Viral Nervous Necrosis

scholarly journals Sea Bass Immunization to Downsize the Betanodavirus Protein Displayed in the Surface of Inactivated Repair-Less Bacteria

Vaccines ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 94
Author(s):  
Lama ◽  
Pereiro ◽  
Novoa ◽  
Coll
Keyword(s):  
Culture Media ◽  
Dicentrarchus Labrax ◽  
Sea Bass ◽  
Surface Expression ◽  
Environmental Safety ◽  
Nervous Necrosis Virus ◽  
Necrosis Virus ◽  
European Sea Bass ◽  
Viral Nervous Necrosis ◽  
Casein Hydrolysates

: This work describes immunization of European sea bass (Dicentrarchus labrax) juveniles against viral nervous necrosis virus (VNNV), a betanodavirus causing worldwide mortalities in many fish species. Protection was obtained with the so-called spinycterin vehicles consisting of irreversibly DNA-damaged DNA-repair-less Escherichia coli displaying at their surface a downsized VNNV coat antigen. In this work we have i) maximized bacterial expression levels by downsizing the coat protein of VNNV to a fragment (frgC91–220) containing most of its previously determined antigenicity, ii) developed a scalable autoinduction culture media for E.coli based in soy-bean rather than in casein hydrolysates, iii) enriched surface expression by screening different anchors from several prokaryotic sources (anchor + frgC91–220 recombinant products), iv) preserved frgC91–220 antigenicity by inactivating bacteria by irreversible DNA-damage by means of Ciprofloxacin, and v) increased safety using a repair-less E.coli strain as chassis for the spinycterins. These spinycterins protected fish against VNNV challenge with partial (Nmistic + frgC91–220) or total (YBEL + frgC91–220) levels of protection, in contrast to fish immunized with frgC91–220 spinycterins. The proposed spinycterin platform has high levels of environmental safety and cost effectiveness and required no adjuvants, thus providing potential to further develop VNNV vaccines for sustainable aquaculture.

scholarly journals Risk factors associated with viral nervous necrosis in hybrid groupers in Malaysia and the high similarity of its causative agent nervous necrosis virus to reassortant red-spotted grouper nervous necrosis virus/striped jack nervous necrosis virus strains

2019 ◽  
Vol 12 (8) ◽  
pp. 1273-1284
Author(s):  
Nurshuhada Ariff ◽  
Azila Abdullah ◽  
Mohamed Noor Amal Azmai ◽  
Najiah Musa ◽  
Sandra Catherine Zainathan
Keyword(s):  
Risk Factors ◽  
Causative Agent ◽  
Life Stage ◽  
Horizontal Transmission ◽  
Nervous Necrosis Virus ◽  
Necrosis Virus ◽  
Viral Nervous Necrosis ◽  
Hybrid Grouper ◽  
Reassortant Strain ◽  
Associated Risk Factors

Background and Aim: Viral nervous necrosis (VNN) is a serious disease of several marine fish species. VNN causes 100% mortality in the larval stages, while lower losses have been reported in juvenile and adult fish. This study aimed to detect the occurrence of VNN while identifying its associated risk factors and the genotypes of its causative agent in a hybrid grouper hatchery in Malaysia. Materials and Methods: A batch of newly hatched hybrid grouper fry (Epinephelus fuscoguttatus X Epinephelus lanceolatus) were followed from the larval stage to market size. Samples of the hybrid groupers, water, live feed, and artificial fish pellets were collected periodically from day 0 to 180 in the hybrid grouper hatchery. Reverse transcription-polymerase chain reaction (RT-PCR) and nested PCR amplifications were carried out on VNN-related sequences. The phylogenetic tree including the sampled causative agent of VNN was inferred from the coat protein genes from all known Betanodavirus species using Molecular Evolutionary Genetics Analysis (MEGA). Pearson's correlation coefficient values were calculated to determine the strength of the correlation between the presence of VNN in hybrid grouper samples and its associated risk factors. Results: A total of 113 out of 146 pooled and individual samples, including hybrid grouper, water, and artificial fish pellet samples, demonstrated positive results in tests for the presence of VNN-associated viruses. The clinical signs of infection observed in the samples included darkened skin, deformation of the backbone, abdominal distension, skin lesions, and fin erosion. VNN was present throughout the life stages of the hybrid groupers, with the first detection occurring at day 10. VNN-associated risk factors included water temperature, dissolved oxygen content, salinity, ammonia level, fish size (adults more at risk than younger stages), and life stage (age). Detection of VNN-associated viruses in water samples demonstrated evidence of horizontal transmission of the disease. All the nucleotide sequences found in this study had high nucleotide identities of 88% to 100% to each other, striped jack nervous necrosis virus (SJNNV), and the reassortant strain red-spotted grouper NNV/SJNNV (RGNNV/SJNNV) isolate 430.2004 (GenBank accession number JN189932.1) (n=26). The phylogenetic analysis showed that quasispecies was present in each VNN-causing virus-positive sample, which differed based on the type of sample and life stage. Conclusion: This study was the first to confirm the existence of a reassortant strain (RGNNV/SJNNV) in hybrid groupers from Malaysia and Southeast Asia. However, the association between the mode of transmission and the risk factors of this virus needs to be investigated further to understand the evolution and potential new host species of the reassortant strain. Keywords: epidemiology, quasispecies, reassortant, red-spotted grouper nervous necrosis virus-striped jack nervous necrosis virus, viral nervous necrosis.

A BIVALENT INACTIVATED VACCINE OF VIRAL NERVOUS NECROSIS VIRUS AND GROUPER IRIDOVIRUS APPLIED TO GROUPER BROODFISH (EPINEPHELUS COIOIDES) REDUCES THE RISK OF VERTICAL TRANSMISSION

2017 ◽  
Vol 43 (03) ◽  
pp. 171-176 ◽  
Author(s):  
Sue-Min Huang ◽  
Jin-Hua Cheng ◽  
Chien Tu ◽  
Tzyy-Ing Chen ◽  
Chun-Ta Lin ◽  
...  
Keyword(s):  
Vertical Transmission ◽  
Neutralizing Antibodies ◽  
High Titer ◽  
Serum Antibody ◽  
Pcr Analysis ◽  
Nervous Necrosis Virus ◽  
Epinephelus Coioides ◽  
Necrosis Virus ◽  
Viral Nervous Necrosis ◽  
Level 1

Forty-one broodfish of orange-spotted groupers (Epinephelus coioides) were selected to evaluate the effectiveness of a viral nervous necrosis virus (VNNV) and grouper iridovirus (GIV) inactivated bivalent vaccine in grouper broodfish. Real-time quantitative PCR analysis showed that a detection rate of 10.5% (2/19) was found in egg specimens of VNNV and GIV, which carried approximately 1780 copies of GIV viral DNA in the egg specimens from broodfish before vaccination. This confirmed the vertical transmission route of GIV in broodfish. A significant increase of the anti-VNNV serum antibody titer was more than 50% in the high titer level (1:1810 to 1:5120) and 45% in the moderate titer level (1:452 to 1:1280), which were higher than those of the anti-GIV display, with 50% (10/20) in a titer of 1:57 to 1:320 and 40% (8/20) in a titer of 1:452 to 1:1280 one month after the vaccination. This result showed that the VNNV is a highly antigenic virus and can effectively induce neutralizing antibodies better than GIV. In addition, the VNNV and GIV viral copy numbers were 97.1 and 1780 copies per [Formula: see text]g host egg DNA from the broodfish before vaccination, respectively. One month after the vaccination, the viral genomes of VNNV and GIV were undetectable in egg specimens. The results show that immunization can induce the production of specific protective neutralizing antibodies, and the infective antigens can thereby be eliminated by the immunity. The results demonstrate that the specific antibodies of GIV and VNNV induced by vaccination can reduce the risk of vertical transmission of VNNV and GIV in grouper broodfish.

scholarly journals Near-Complete Genome Sequence of a Fish Nervous Necrosis Virus Isolated from a Clinical Disease Outbreak in Farm-Reared Bream Sparus aurata in Spain

2018 ◽  
Vol 6 (1) ◽  
Author(s):  
Panagiota Stathopoulou ◽  
Nausika Rafailidou ◽  
Kostas Tzokas ◽  
Costas Batargias ◽  
George Tsiamis
Keyword(s):  
Phylogenetic Tree ◽  
Genome Sequence ◽  
Complete Genome Sequence ◽  
Viral Genome ◽  
Complete Genome ◽  
Sparus Aurata ◽  
Disease Outbreak ◽  
Nervous Necrosis Virus ◽  
Necrosis Virus ◽  
Viral Nervous Necrosis

ABSTRACT Sparus aurata larvae infected by viral nervous necrosis were collected from an aquaculture fish farm. The isolated viral genome, composed of two segments (RNA1 and RNA2), was sequenced and analyzed comparatively. Phylogenetic tree analyses revealed that the isolated strain is a reassortant, exhibiting a red-spotted grouper nervous necrosis virus (RGNNV)-type RNA1 and a striped jack nervous necrosis virus (SJNNV)-type RNA2.

scholarly journals Prevalence of Infectious Spleen and Kidney Necrosis Virus (ISKNV), Nervous Necrosis Virus (NNV) and Ectoparasites in Juvenile Epinephelus spp. Farmed in Aceh, Indonesia

Pathogens ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 578 ◽  
Author(s):  
Bakhtiar Sah Putra ◽  
Paul M. Hick ◽  
Evelyn Hall ◽  
Richard J. Whittington ◽  
Razi Khairul ◽  
...  
Keyword(s):  
Parasite Load ◽  
Nervous Necrosis Virus ◽  
Necrosis Virus ◽  
Cross Sectional Survey ◽  
Cross Sectional ◽  
Viral Nervous Necrosis ◽  
Apparent Prevalence ◽  
Targeted Sampling ◽  
Hybrid Grouper ◽  
Aquatic Pathogens

A cross-sectional survey was used to estimate the prevalence of infections with the Infectious spleen and kidney necrosis virus (ISKNV, Megalocytivirus), nervous necrosis virus (NNV, Betanodavirus), and infestations with ectoparasites during the rainy season in juvenile grouper (Epinephelus spp.) farmed in Aceh, Indonesia. The survey was intended to detect aquatic pathogens present at 10% prevalence with 95% confidence, assuming 100% sensitivity and specificity using a sample size of 30 for each diagnostic test. Eight populations of grouper from seven farms were sampled. Additional targeted sampling was conducted for populations experiencing high mortality. Infection with NNV was detected at all farms with seven of the eight populations being positive. The apparent prevalence for NNV ranged from 0% (95% CI: 0–12) to 73% (95% CI: 54–88). All of the fish tested from the targeted samples (Populations 9 and 10) were positive for NNV and all had vacuolation of the brain and retina consistent with viral nervous necrosis (VNN). Coinfections with ISKNV were detected in five populations, with the highest apparent prevalence being 13% (95% CI: 4–31%). Trichodina sp., Cryptocaryon irritans and Gyrodactylus sp. were detected at three farms, with 66% to 100% of fish being infested. Hybrid grouper sourced from a hatchery were 5.4 and 24.9 times more likely to have a NNV infection and a higher parasite load compared to orange-spotted grouper collected from the wild (p < 0.001). This study found that VNN remains a high-impact disease in grouper nurseries in Aceh, Indonesia.

scholarly journals Identification of Host-Specificity Determinants in Betanodaviruses by Using Reassortants between Striped Jack Nervous Necrosis Virus and Sevenband Grouper Nervous Necrosis Virus

2004 ◽  
Vol 78 (3) ◽  
pp. 1256-1262 ◽  
Author(s):  
Tokinori Iwamoto ◽  
Yasushi Okinaka ◽  
Kazuyuki Mise ◽  
Koh-Ichiro Mori ◽  
Misao Arimoto ◽  
...  
Keyword(s):  
Coat Protein ◽  
Host Specificity ◽  
Polyclonal Antibodies ◽  
Infected Fish ◽  
Nervous Necrosis Virus ◽  
Genomic Segment ◽  
Necrosis Virus ◽  
Reassortant Virus ◽  
Transcription System ◽  
Viral Nervous Necrosis

ABSTRACT Betanodaviruses, the causal agents of viral nervous necrosis in marine fish, have bipartite positive-sense RNAs as genomes. The larger genomic segment, RNA1 (3.1 kb), encodes an RNA-dependent RNA polymerase, and the smaller genomic segment, RNA2 (1.4 kb), codes for the coat protein. Betanodaviruses have marked host specificity, although the primary structures of the viral RNAs and encoded proteins are similar among betanodaviruses. However, no mechanism underlying the host specificity has yet been reported. To evaluate viral factors that control host specificity, we first constructed a cDNA-mediated infectious RNA transcription system for sevenband grouper nervous necrosis virus (SGNNV) in addition to that for striped jack nervous necrosis virus (SJNNV), which was previously established by us. We then tested two reassortants between SJNNV and SGNNV for infectivity in the host fish from which they originated. When striped jack and sevenband grouper larvae were bath challenged with the reassortant virus comprising SJNNV RNA1 and SGNNV RNA2, sevenband groupers were killed exclusively, similar to inoculation with SGNNV. Conversely, inoculations with the reassortant virus comprising SGNNV RNA1 and SJNNV RNA2 killed striped jacks but did not affect sevenband groupers. Immunofluorescence microscopic studies using anti-SJNNV polyclonal antibodies revealed that both of the reassortants multiplied in the brains, spinal cords, and retinas of infected fish, similar to infections with parental virus inoculations. These results indicate that viral RNA2 and/or encoded coat protein controls host specificity in SJNNV and SGNNV.

scholarly journals Sequence of the non-structural protein gene encoded by RNA1 of striped jack nervous necrosis virus

1999 ◽  
Vol 80 (11) ◽  
pp. 3019-3022 ◽  
Author(s):  
Takahiro Nagai ◽  
Toyohiko Nishizawa
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequences ◽  
Nervous Necrosis Virus ◽  
Structural Protein ◽  
Necrosis Virus ◽  
Rna Molecules ◽  
Viral Nervous Necrosis ◽  
The Family ◽  
Amino Acid Levels ◽  
Structural Protein Gene

Striped jack nervous necrosis virus (SJNNV), the causative agent of viral nervous necrosis in marine fish, is a member of the family Nodaviridae whose genome consists of two positive-sense RNA molecules encapsidated in a single virion. In this study, the nucleotide sequence of SJNNV RNA1 was determined. The SJNNV RNA1 was 3081 bases long and contained a single ORF encoding 983 aa of approximately 110 kDa. The sequence identities between RNA1 of SJNNV and RNA1 of insect nodaviruses were 28% at the nucleotide and amino acid levels, although the conserved motifs for the RNA-dependent RNA polymerase were located at almost the same positions in the amino acid sequences. The present study, together with our previous work on SJNNV RNA2, suggests that a new genus, Piscinodavirus, should be created in the family Nodaviridae.

scholarly journals Histopathological of Brain, Eye, Liver, Spleen Organs of Grouper Suspected VNN in Penyambuan Village, North Lombok

2021 ◽  
Vol 21 (1) ◽  
pp. 140
Author(s):  
Agustina Rahmawanti ◽  
Dewi Nur’aini Setyowati ◽  
Alis Mukhlis
Keyword(s):  
Research Method ◽  
Economic Value ◽  
Accurate Method ◽  
Test Sample ◽  
Wide Distribution ◽  
Nervous Necrosis Virus ◽  
Necrosis Virus ◽  
Viral Nervous Necrosis ◽  
Epinephelus Fuscoguttatus ◽  
The Brain

Cantang grouper is one of the leading NTB commodities that have high economic value. Cantang grouper (Epinephelus fuscoguttatus) has a wide distribution, one of which is in Penyambuan Village, North Lombok Regency. The disease that often attacks grouper fish is VNN (Viral Nervous Necrosis). One of the methods that can be used to detect VNN is the histopathological method. The purpose of this study was to determine the suspected cases and levels of infection with the VNN (Viral Nervous Necrosis) virus in grouper fish (Epinephelus fuscoguttatus) cultivated in Penyambuan Hamlet, Tanjung District, North Lombok Regency by using the histopathological method. The research method used is descriptive by explaining the results obtained from the histopathological test of 3 samples taken by looking at the presence or absence of necrosis in the eye and brain organs of the test sample. The results of observations using a microscope on the test sample after the histopathological process showed that the second sample (S2) of cantang grouper from the KJA in Pemambuan was suspected to be positive for VNN infection, as seen from the presence of necrosis in the form of vacuoles in the brain and eye organs in the level of chronic infection. From the results of this study, it is suggested that further research be carried out in the form of confirmation of the results using a more accurate method, namely real-time PCR. This study can serve as a detection guide for samples of suspected VNN.

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