Experimental susceptibility of European sea bass and Senegalese sole to different betanodavirus isolates

Souto, Sandra; López-Jimena, Benjamín; Alonso, M. Carmen; García-Rosado, Esther; Bandı́n, Isabel

doi:10.1016/j.vetmic.2015.02.030

Cited by 41 publications

(48 citation statements)

References 44 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Interestingly, although the RGNNV strain showed a meaningful delay in reaching the brain compared to the others, at the end of the experiment it yielded the highest values (around 1 log higher than the reassortant strain and more than 2 logs higher with respect to the SJNNV strain in both RNA1 copies and viral titre). We have already reported that the reassortant strain causes more acute signs and earlier mortality after bath infection in Senegalese sole than the parental RGNNV and SJNNV strains (Souto, Lopez‐Jimena et al., ). Therefore, early and sustained viral replication seems to be more relevant for betanodavirus pathogenicity in this species than a high final viral production.…”

Section: Discussionmentioning

confidence: 90%

Betanodavirus infection in bath‐challenged Solea senegalensis juveniles: A comparative analysis of RGNNV, SJNNV and reassortant strains

Souto

Olveira

Alonso

et al. 2018

Journal of Fish Diseases

View full text Add to dashboard Cite

Senegalese sole has been shown to be highly susceptible to betanodavirus infection, although virulence differences were observed between strains. To study the mechanisms involved in these differences, we have analysed the replication in brain tissue of three strains with different genotypes during 15 days after bath infection. In addition, possible portals of entry for betanodavirus into sole were investigated. The reassortant RGNNV/SJNNV and the SJNNV strain reached the brain after 1 and 2 days postinfection, respectively. Although no RGNNV replication was detected until day 3-4 postinfection, at the end of the experiment this strain yielded the highest viral load; this is in accordance with previous studies in which sole infected with the reassortant showed more acute signs and earlier mortality than the RGNNV and SJNNV strains. Differences between strains were also observed in the possible portals of entry. Thus, whereas the reassortant strain could infect sole mainly through the skin or the oral route, and, to a minor extent, through the gills, the SJNNV strain seems to enter fish only through the gills and the RGNNV strain could use all tissues indistinctly. Taken together, all these results support the hypothesis that reassortment has improved betanodavirus infectivity for sole.

show abstract

Section: Discussionmentioning

confidence: 90%

Betanodavirus infection in bath‐challenged Solea senegalensis juveniles: A comparative analysis of RGNNV, SJNNV and reassortant strains

Souto

Olveira

Alonso

et al. 2018

Journal of Fish Diseases

View full text Add to dashboard Cite

show abstract

“…However, the increasing number of reports of RGNNV/SJNNV-related disease in S. aurata documented in recent years suggests that this type of reassortant might represent an emerging problem for Mediterranean sea bream farming. Notably, the same reassortant strain has recently proved to possess a peculiar tropism and a high pathogenicity also for flatfish1631.…”

Section: Discussionmentioning

confidence: 99%

“…In the cohabitation experiences performed in farm 2, virus- positive survivors were unable to transfer the virus to bigger sea bream and to sea bass. Indeed, the expected resistance of this latter species to the reassortant RGNNV/SJNNV may account for the lack of transmission of the disease1617. However, for the bigger cohabitating sea bream, this could be due to the higher resistance of elder fish or to the reduced infectivity of the survivors after the acute phase.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Viral nervous necrosis in gilthead sea bream (Sparus aurata) caused by reassortant betanodavirus RGNNV/SJNNV: an emerging threat for Mediterranean aquaculture

Toffan

Pascoli

Pretto

et al. 2017

Sci Rep

100

View full text Add to dashboard Cite

Viral nervous necrosis (VNN) certainly represents the biggest challenge for the sustainability and the development of aquaculture. A large number of economically relevant fish species have proven to be susceptible to the disease. Conversely, gilthead sea bream has generally been considered resistant to VNN, although it has been possible to isolate the virus from apparently healthy sea bream and sporadically from affected larvae and postlarvae. Unexpectedly, in 2014–2016 an increasing number of hatcheries in Europe have experienced mass mortalities in sea bream larvae. Two clinical outbreaks were monitored over this time span and findings are reported in this paper. Despite showing no specific clinical signs, the affected fish displayed high mortality and histological lesions typical of VNN. Fish tested positive for betanodavirus by different laboratory techniques. The isolates were all genetically characterized as being reassortant strains RGNNV/SJNNV. A genetic characterization of all sea bream betanodaviruses which had been isolated in the past had revealed that the majority of the strains infecting sea bream are actually RGNNV/SJNNV. Taken together, this information strongly suggests that RGNNV/SJNNV betanodavirus possesses a particular tropism to sea bream, which can pose a new and unexpected threat to the Mediterranean aquaculture.

show abstract

“…The high susceptibility of Senegalese sole to betanodavirus infection has been previously demonstrated (Souto et al . ,b). This species is therefore a potential source of infection that could jeopardize species cultivated in close proximity.…”

Section: Introductionmentioning

confidence: 99%

Reassortant betanodavirus infection in turbot (Scophthalmus maximus)

Souto

Olveira

Dopazo

et al. 2016

Journal of Fish Diseases

View full text Add to dashboard Cite

In this study, the susceptibility of turbot juveniles to two betanodavirus strains was assessed, a RGNNV/SJNNV reassortant (Ss160.03) and a SJNNV strain. The reassortant isolate exhibits a slightly modified SJNNV CP, with two amino acid substitutions in the C-terminal domain (positions 247 and 270). To analyse the role of these residues as virulence and host determinants in turbot, three recombinant strains (rSs160.03 , rSs160.03 , rSs160.03 ) harbouring site-specific mutations in the CP sequence were also tested in experimental trials. Moderate mortalities (up to 50%) were recorded at 18 °C in the fish challenged with the Ss160.03 strain, whereas low mortalities (17%) were observed in the group challenged with the SJNNV strain. A slight decrease (around 10%) was observed in the mortalities caused by the mutants rSs160.03 and rSs160.03 , whilst the mutation of both positions reduced mortality by more than half of that observed in fish challenged with the wild strain. These results are confirmed by the replication in brain tissues, because whereas the wild strain was detected from 5 to 30 dpi and reached the highest viral load, the recombinant virus harbouring both mutations was not detected in the brain until 20 dpi and with a moderate viral load.

show abstract

Experimental susceptibility of European sea bass and Senegalese sole to different betanodavirus isolates

Cited by 41 publications

References 44 publications

Betanodavirus infection in bath‐challenged Solea senegalensis juveniles: A comparative analysis of RGNNV, SJNNV and reassortant strains

Betanodavirus infection in bath‐challenged Solea senegalensis juveniles: A comparative analysis of RGNNV, SJNNV and reassortant strains

Viral nervous necrosis in gilthead sea bream (Sparus aurata) caused by reassortant betanodavirus RGNNV/SJNNV: an emerging threat for Mediterranean aquaculture

Reassortant betanodavirus infection in turbot (Scophthalmus maximus)

Contact Info

Product

Resources

About