Different survival of three populations of European sea bass (Dicentrarchus labrax) following challenge with two variants of nervous necrosis virus (NNV)

Barsøe, Sofie; Allal, François; Vergnet, Alain; Vandeputte, Marc; Olesen, Niels Jørgen; Schmidt, J. F.; Larsen, Cathrine Agnete; Cuenca, Argelia; Vendramin, Niccoló

doi:10.1016/j.aqrep.2021.100621

Cited by 8 publications

(9 citation statements)

References 50 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In these studies, primarily the latter one, it is also shown that mortality significantly increases with temperature in RGNNV infections and particularly with this isolate, reaching optimal values at 25-30 • C. These results confirm in vitro replication assessments in response to temperature using some of the same isolates, including 283.2009 [63]. Recently, the 283.2009 isolate has also shown a high lethality when experimentally infecting three different populations of European seabass juveniles, although with different mortality rates seen between them (47.8-85.8%), probably due to natural protection peculiarities [64].…”

Section: Nnv Isolation and Identificationsupporting

confidence: 76%

Update on the Inactivation Procedures for the Vaccine Development Prospects of a New Highly Virulent RGNNV Isolate

et al. 2021

View full text Add to dashboard Cite

Viral nervous necrosis (VNN) caused by the nervous necrosis virus (NNV) affects a broad range of primarily marine fish species, with mass mortality rates often seen among larvae and juveniles. Its genetic diversification may hinder the effective implementation of preventive measures such as vaccines. The present study describes different inactivation procedures for developing an inactivated vaccine against a new NNV isolate confirmed to possess deadly effects upon the European seabass (Dicentrarchus labrax), an important Mediterranean farmed fish species that is highly susceptible to this disease. First, an NNV isolate from seabass adults diagnosed with VNN was rescued and the sequences of its two genome segments (RNA1 and RNA2) were classified into the red-spotted grouper NNV (RGNNV) genotype, closely clustering to the highly pathogenic 283.2009 isolate. The testing of different inactivation procedures revealed that the virus particles of this isolate showed a marked resistance to heat (for at least 60 °C for 120 min with and without 1% BSA) but that they were fully inactivated by 3 mJ/cm2 UV-C irradiation and 24 h 0.2% formalin treatment, which stood out as promising NNV-inactivation procedures for potential vaccine candidates. Therefore, these procedures are feasible, effective, and rapid response strategies for VNN control in aquaculture.

show abstract

Section: Nnv Isolation and Identificationsupporting

confidence: 76%

Update on the Inactivation Procedures for the Vaccine Development Prospects of a New Highly Virulent RGNNV Isolate

et al. 2021

View full text Add to dashboard Cite

show abstract

“…Study 2: European sea bass from an Atlantic population [33,34] was retrieved from MARBEC, Université Montpellier, CNRS, Ifremer, IRD, Palavas-les-Flots, France (weight: 5 g ± 2 g). Upon arrival, the fish were divided in two groups ("Group 1" and "Group 2").…”

Section: Fish and Setupmentioning

confidence: 99%

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

et al. 2021

Self Cite

View full text Add to dashboard Cite

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.

show abstract

“…Live RGNNV (strain 283.2009 [49], kindly provided by Dr. Anna Toffan, IZSVe, Italy) was propagated on a 1-day-old monolayer of SSN1 cells [50] at 25 • C as previously described [51]. The cell line was tested free from mycoplasma every 6 months.…”

Section: Virus and Experimental Challengementioning

confidence: 99%

“…A multiplex TaqMan one step RT-qPCR targeting both the NNV RNA1 and the housekeeping gene elongation factor 1-alpha (elf1a) followed a previously established protocol [51] (Table 9). A dilution series of one sample was included in each run and used to manually set an equal threshold value before exporting the Cq values from MxPro to Microsoft Excel and to calculate the efficiency (Table 9).…”

Section: Detection Of Nnv By Rt-qpcrmentioning

confidence: 99%

See 1 more Smart Citation

Nervous Necrosis Virus-like Particle (VLP) Vaccine Stimulates European Sea Bass Innate and Adaptive Immune Responses and Induces Long-Term Protection against Disease

et al. 2021

Self Cite

View full text Add to dashboard Cite

The rapidly increasing Mediterranean aquaculture production of European sea bass is compromised by outbreaks of viral nervous necrosis, which can be recurrent and detrimental. In this study, we evaluated the duration of protection and immune response in sea bass given a single dose of a virus-like particle (VLP)-based vaccine. Examinations included experimental challenge with nervous necrosis virus (NNV), serological assays for NNV-specific antibody reactivity, and immune gene expression analysis. VLP-vaccinated fish showed high and superior survival in challenge both 3 and 7.5 months (1800 and 4500 dd) post-vaccination (RPS 87 and 88, OR (surviving) = 16.5 and 31.5, respectively, p < 0.01). Although not providing sterile immunity, VLP vaccination seemed to control the viral infection, as indicated by low prevalence of virus in the VLP-vaccinated survivors. High titers of neutralizing and specific antibodies were produced in VLP-vaccinated fish and persisted for at least ~9 months post-vaccination as well as after challenge. However, failure of immune sera to protect recipient fish in a passive immunization trial suggested that other immune mechanisms were important for protection. Accordingly, gene expression analysis revealed that VLP-vaccination induced a mechanistically broad immune response including upregulation of both innate and adaptive humoral and cellular components (mx, isg12, mhc I, mhc II, igm, and igt). No clinical side effects of the VLP vaccination at either tissue or performance levels were observed. The results altogether suggested the VLP-based vaccine to be suitable for clinical testing under farming conditions.

show abstract

Different survival of three populations of European sea bass (Dicentrarchus labrax) following challenge with two variants of nervous necrosis virus (NNV)

Cited by 8 publications

References 50 publications

Update on the Inactivation Procedures for the Vaccine Development Prospects of a New Highly Virulent RGNNV Isolate

Update on the Inactivation Procedures for the Vaccine Development Prospects of a New Highly Virulent RGNNV Isolate

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

Nervous Necrosis Virus-like Particle (VLP) Vaccine Stimulates European Sea Bass Innate and Adaptive Immune Responses and Induces Long-Term Protection against Disease

Contact Info

Product

Resources

About