scholarly journals Prevalence of Betanodavirus in Sea Bass (Dicentrarchus Labrax) for All Production Stages in Turkey

2021 ◽  
Author(s):  
Murat KAPLAN ◽  
Mehmet Taner KARAOĞLU
Keyword(s):  
Sea Water ◽  
Age Groups ◽  
Dicentrarchus Labrax ◽  
Sea Bass ◽  
Epidemiological Studies ◽  
Nervous Necrosis Virus ◽  
Virus Genotype ◽  
Viral Nervous Necrosis ◽  
Water Origin ◽  
Production Stages

Abstract Viral Nervous Necrosis (VNN) is one of the most important problems in sea bass aquaculture. Although there are many studies in the world on detection and molecular characterization of betanodaviruses causative agent of VNN, there are not enough studies related to prevalance to provide epidemiological maps. The purpose of this study was to investigate the betanodavirus prevalence in all bass hatcheries actively operating and in some farms in Turkey by RT-qPCR. A total of 2460 samples including fertilized egg, prelarva, postlarva, and fingerling were collected from 16 hatcheries as covering all production stages. A total of 600 sea bass were also collected from 20 farms. Betanodavirus was detected in a hatchery and a farm in fingerling sized sea bass and prevalances were found to be 6.25% and 5%, respectively. Virus isolation initially could not be achieved in E-11 but later SSN-1. Partial genome analysis of both RNA1 and RNA2 segments of the viruses, revealed that they were Redspotted grouper nervous necrosis virus genotype endemic in the Mediterranean basin. The absence of mortality related to VNN in the hatchery and farm, the healthy appearance of the sea bass, the low viral load detected and also output of retrospective epidemiological studies indicate that the infection is subclinical. Not detecting betanodavirus in other age groups where biosafety is implemented indicates that there is no active infection. In the light of these findings, it can be concluded that there are no circulating betanodavirus in hatcheries and the detected virus could be of sea-water origin.

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 Sea Bass Immunization to Downsized Betanodavirus Protein Displayed in The Surface of Dna-Damaged Repair-Less Bacteria

2019 ◽  
Author(s):  
Raquel Lama ◽  
Patricia Pereiro ◽  
Beatriz Novoa ◽  
Julio Coll
Keyword(s):  
Dicentrarchus Labrax ◽  
Sea Bass ◽  
Surface Expression ◽  
Environmental Safety ◽  
Small Fish ◽  
Nervous Necrosis Virus ◽  
Necrosis Virus ◽  
European Sea Bass ◽  
C Protein ◽  
Viral Nervous Necrosis

This work describes practical 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 in irreversibly DNA-damaged DNA-repair-less E.coli displaying at their surface a downsized antigen. In this work we, i) maximized bacterial expression levels by downsizing the C protein to a fragment (frgC91-220) containing most of its antigenicity, ii) developed an scalable autoinduction bacterial media based in soy-bean increasing membrane display and reproducibility, iii) enriched surface expression by screening different anchors from several prokaryotic origins (anchor+frgC91-220), 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 spinycterin chassis. These second generation of spinycterins protected fish against VNNV challenge with partial (Nmistic+frgC91-220) or 100 % (YBEL+frgC91-220 ) protection, in contrast to those fish immunized with frgC91-220 spinycterins. The proposed spinycterin platform has high levels of environmental safety and cost effectiveness, thus providing potential for small fish vaccines for sustainable aquaculture.

scholarly journals Long-Term Protection and Serologic Response of European Sea Bass Vaccinated with a Betanodavirus Virus-Like Particle Produced in Pichia pastoris

Vaccines ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 447
Author(s):  
Sofie Barsøe ◽  
Anna Toffan ◽  
Francesco Pascoli ◽  
Ansgar Stratmann ◽  
Tobia Pretto ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
High Titer ◽  
Dicentrarchus Labrax ◽  
Sea Bass ◽  
Nervous Necrosis Virus ◽  
European Sea Bass ◽  
Post Vaccination ◽  
Serologic Response ◽  
Viral Nervous Necrosis ◽  
Virus Like Particle

Viral Nervous Necrosis (VNN) causes high mortality and reduced growth in farmed European sea bass (Dicentrarchus labrax) in the Mediterranean. In the current studies, we tested a novel Pichia-produced virus-like particle (VLP) vaccine against VNN in European sea bass, caused by the betanodavirus “Red-Spotted Grouper Nervous Necrosis Virus” (RGNNV). European sea bass were immunized with a VLP-based vaccine formulated with different concentrations of antigen and with or without adjuvant. Antibody response was evaluated by ELISA and serum neutralization. The efficacy of these VLP-vaccine formulations was evaluated by an intramuscular challenge with RGNNV at different time points (1, 2 and 10 months post-vaccination) and both dead and surviving fish were sampled to evaluate the level of viable virus in the brain. The VLP-based vaccines induced an effective protective immunity against experimental infection at 2 months post-vaccination, and even to some degree at 10 months post-vaccination. Furthermore, the vaccine formulations triggered a dose-dependent response in neutralizing antibodies. Serologic response and clinical efficacy, measured as relative percent survival (RPS), seem to be correlated with the administered dose, although for the individual fish, a high titer of neutralizing antibodies prior to challenge was not always enough to protect against disease. The efficacy of the VLP vaccine could not be improved by formulation with a water-in-oil (W/O) adjuvant. The developed RGNNV-VLPs show a promising effect as a vaccine candidate, even without adjuvant, to protect sea bass against disease caused by RGNNV. However, detection of virus in vaccinated survivors means that it cannot be ruled out that survivors can transmit the virus.

Assimilation of dissolved glucose from sea water by the sea bass Dicentrarchus labrax and the sea bream Sparus aurata

1994 ◽  
Vol 120 (2) ◽  
pp. 181-186 ◽  
Author(s):  
J. P. Diaz ◽  
L. mani-Ponset ◽  
E. Guyot ◽  
R. Connes
Keyword(s):  
Sea Water ◽  
Sparus Aurata ◽  
Dicentrarchus Labrax ◽  
Sea Bass ◽  
Sea Bream

Co-culture of Ulva sp. and Dicentrarchus labrax in Recirculating Aquaculture System: effects on growth, retention of nutrients and fatty acid profile

2020 ◽  
Vol 33 ◽  
pp. 19
Author(s):  
Evanthia Chatzoglou ◽  
Panorea Kechagia ◽  
Aristeidis Tsopelakos ◽  
Helen Miliou
Keyword(s):  
Fish Oil ◽  
Sea Water ◽  
Dicentrarchus Labrax ◽  
Sea Bass ◽  
Recirculating Aquaculture System ◽  
Fish Oil Replacement ◽  
European Sea Bass ◽  
Integrated Aquaculture ◽  
Recirculating Aquaculture ◽  
Aquaculture System

European sea bass and Ulva sp. were co-cultured in different tanks of an indoor Recirculating Aquaculture System (Ulva-RAS) with bacterial biofilter, in an effort to optimize the efficiency of the system and to further decrease the waste effluent. A system with similar culture conditions, without Ulva, was used as a control-RAS to elucidate integration effects on growth performance and chemical composition of sea bass. The role of Ulva on N and P concentrations, gas (O2, CO2) and pH in water was also investigated. Fish were fed a diet of fish oil replacement (55%) with a mixture of rapeseed oil and palm oil (1:1). Our data showed that Ulva could uptake N and P nutrients, but could also enrich sea water with phosphates. Sea bass reared in Ulva-RAS exhibited isometric growth, while fish in control-RAS showed a positive allometric growth and an increased variance of body weight and length. In addition, sea bass in Ulva-RAS demonstrated significantly higher levels of condition factor (K), feed intake, protein, lipid, P, EPA and DHA content (% wet weight of total body) and lipid productive value, compared to fish in control-RAS. Ulva, after bi-weekly culture, showed increased protein content (60%) compared to wild seaweed collected nearshore. Cultivated Ulva obtained dark green color, doubled chlorophyll concentrations, and exhibited lower levels of saturated and higher levels of certain monounsaturated and n-3 polyunsaturated fatty acids, indicating increased photosynthetic activity. Present results revealed the beneficial effects of Ulva on sea bass growth and quality, which led to an improved response to the nutritional stress imposed by the fish oil replacement with vegetable oils, thus contributing to a sustainable aquaculture. Moreover, it was concluded that Ulva could improve water quality by increasing pH and O2, reducing CO2 and contribute to bioremediation of ammonia and nitrates from water in integrated aquaculture.

scholarly journals Induction of a Protective Immune Response against Viral Nervous Necrosis in the European Sea Bass Dicentrarchus labrax by Using Betanodavirus Virus-Like Particles

2006 ◽  
Vol 80 (20) ◽  
pp. 10201-10207 ◽  
Author(s):  
R. Thiéry ◽  
J. Cozien ◽  
J. Cabon ◽  
F. Lamour ◽  
M. Baud ◽  
...  
Keyword(s):  
Immune Response ◽  
Expression System ◽  
Dicentrarchus Labrax ◽  
Sea Bass ◽  
Baculovirus Expression System ◽  
Single Type ◽  
European Sea Bass ◽  
Virus Like Particles ◽  
Viral Nervous Necrosis ◽  
Baculovirus Expression

ABSTRACT Betanodaviruses are causative agents of viral nervous necrosis (VNN), a devastating disease of cultured marine fish worldwide. Virus particles contain a single type of coat protein that spontaneously assembles into virus-like particles (VLPs) when expressed in a baculovirus expression system. In the present study, the immunogenicity of betanodavirus VLPs and the protection they confer against VNN in the European sea bass Dicentrarchus labrax were investigated. Enzyme-linked immunosorbent assay and seroneutralization tests performed on plasma from fish vaccinated intramuscularly with doses as low as 0.1 μg of VLPs indicated that the VLPs elicited the synthesis of specific antibetanodavirus antibodies with neutralizing activity. Moreover, fish vaccinated with VLPs were protected from challenge with live virus. Both the immune response and the protective effect against viral challenge were dose dependent. Reverse transcription-PCR data indicated that higher doses of vaccine also reduced the number of fish containing detectable quantities of betanodavirus RNA on day 30 after challenge. Taken together these data strongly support the hypothesis that VLPs obtained in the baculovirus expression system may represent an effective vaccine against VNN.

Sign in / Sign up

Export Citation Format

Share Document