High prevalence of betanodavirus barfin flounder nervous necrosis virus as well as red‐spotted grouper nervous necrosis virus genotype in shellfish

Kim, Y C; Kwon, Woo Ju; Kim, M S; Kim, K I; Min, Joon Gyu; Jeong, Hyun Do

doi:10.1111/jfd.12702

Cited by 19 publications

(31 citation statements)

References 34 publications

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“…However, routine surveys conducted on farmed fish have revealed the existence of a great number of asymptomatic individuals which could act as carriers. Therefore, NNV asymptomatic carriers have been detected among farmed species that have been reported to undergo disease outbreaks, such as European sea bass, golden pompano, Japanese parrotfish (Oplegnathus fasciatus), Japanese flounder (Paralichthys olivaceus), different grouper species (E. lanceolatus, E. akaara and E. awooara), red drum (Sciaenops ocellatus), dusky sinefoot (Siganus fuscescens) and tiger puffer (Takifugu rubripes) [56,66,68,131]. In all these cases, except the detection in Japanese parrot fish, which was not typed, viruses causing non-clinical infection belonged to the RGNNV genotype.…”

Section: Ver Outbreaks and Nnv Detections In Farmed Fishmentioning

confidence: 99%

Betanodavirus and VER Disease: A 30-year Research Review

2020

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The outbreaks of viral encephalopathy and retinopathy (VER), caused by nervous necrosis virus (NNV), represent one of the main infectious threats for marine aquaculture worldwide. Since the first description of the disease at the end of the 1980s, a considerable amount of research has gone into understanding the mechanisms involved in fish infection, developing reliable diagnostic methods, and control measures, and several comprehensive reviews have been published to date. This review focuses on host-virus interaction and epidemiological aspects, comprising viral distribution and transmission as well as the continuously increasing host range (177 susceptible marine species and epizootic outbreaks reported in 62 of them), with special emphasis on genotypes and the effect of global warming on NNV infection, but also including the latest findings in the NNV life cycle and virulence as well as diagnostic methods and VER disease control.

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Section: Ver Outbreaks and Nnv Detections In Farmed Fishmentioning

confidence: 99%

Betanodavirus and VER Disease: A 30-year Research Review

2020

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“…Only RGNNV has been detected in clinically/subclinically infected fish and invertebrate tissues in Korea (Gomez, Baeck, Kim, Choresca, & Park, ,b). However, recently, BFNNV has been detected in large amounts in shellfish, suggesting an inflow of other genotypes (Kim et al., ).…”

Section: Introductionmentioning

confidence: 99%

“…Kim et al. () have recently developed a “detection semi‐nested two‐step RT‐PCR” (DSN‐2 RT‐PCR) with primer sets specific to a conserved region in the RNA2 fragment of four major genotypes for detecting NNVs in tissues of various shellfish species. Positive samples obtained in the DSN‐2 RT‐PCR were further analysed to distinguish the genotype of NNVs using a regular discriminative multiplex two‐step RT‐PCR (rDMT‐2 RT‐PCR) with primer sets designed from variable regions specific to each genotype (Kim et al., ).…”

Section: Introductionmentioning

confidence: 99%

Isolation and initial characterization of new betanodaviruses in shellfish

Kim

Kwon

Min

et al. 2018

Transbound Emerg Dis

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Betanodaviruses cause the disease viral nervous necrosis (VNN) in finfish. Using a novel approach with two consecutive PCRs, detection semi-nested two-step RT-PCR (DSN-2 RT-PCR) and discriminative multiplex two-step RT-PCR (DMT-2 RT-PCR), we have identified the presence of a new type of betanodavirus in shellfish and called it Korean shellfish nervous necrosis virus (KSNNV). Partial nucleotide sequences of the T4 region in RNA2 fragment of KSNNVs were 73%-75% homologous to those of other reported genotypes and formed a new cluster of betanodavirus in phylogenetic tree analysis. Successful isolation of KSNNV was achieved in two of six shellfish samples containing high concentrations of virus using the blind passage method, and the typical shapes of betanodavirus were confirmed in KSNNV-KOR1 by electron microscopy. In the experimental infection test, seven of 14 fish species showed susceptibility to KSNNV-KOR1 isolate but without clinical signs or death. Although the range of susceptible host species was not significantly different from the RGNNV type, the concentration of KSNNV in the brain of infected fish (10 -10 copies/mg brain) was much lower compared to that found in sevenband grouper (Epinephelus septemfasciatus Thunberg) sampled in the moribund stage with RGNNV infection (10 -10 copies/mg brain). However, histopathological analyses showed the presence of multiple vacuoles in brains of all KSNNV-infected fish at 14 days postinjection. In detection test, as a single or multiple type with the other genotype(s) (RGNNV or BFNNV), the prevalence of KSNNV was 8.4% and 8.7% in domestic (62 of 741 samples) and Chinese samples (12 of 138 samples), respectively, but not in finfish. We propose that KSNNVs obtained from shellfish be classified into a separate and new genotype of betanodavirus.

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“…KSNNV‐KOR1 (isolated from Pacific oyster in Korea in 2013, Kim, Kwon, Min, et al, ) and SFRG10/2012BGGa1 isolates (isolated from granular ark in Korea in 2012, Kim, Kwon, Kim, et al, ) representing KSNNV and RGNNV, respectively, were used. Isolates were cultured on E‐11 cell line (ECACC no.…”

Section: Methodsmentioning

confidence: 99%

Complete genome sequence and pathogenic analysis of a new betanodavirus isolated from shellfish

Kim

Kwon

Min

et al. 2019

Journal of Fish Diseases

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We determined the complete genomic RNA sequence of a new type of betanodavirus Korea shellfish nervous necrosis virus (KSNNV) isolated from shellfish. Compared with other isolates representing four genotypes of betanodaviruses, the identity of the whole nucleotide sequence of the virus was in the range of 76%–83% with the presence of specific genetic motifs and formed a separate new branch in the phylogenetic analysis. In pathogenic analysis by immersion method, KSNNV‐KOR1 shows 100% cumulative mortality like SFRG10/2012BGGa1 (RGNNV) in newly hatched sevenband grouper and mandarin fish, which is clearly different from those found in negative control groups. There were no significant differences in increasing rates of mortality and viral intra‐tissue concentration of larval fishes infected with KSNNV‐KOR1 at both 20 and 25°C water temperature. Histopathological examination of each fish species in the moribund stage revealed the presence of clear vacuoles in both brain and retinal tissues similar to typical histopathology features of RGNNV. In the present study, we first report a new betanodavirus from shellfish as the aetiological agent of viral nervous necrosis disease in fish with complete genomic nucleotide sequence and pathogenic analysis.

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High prevalence of betanodavirus barfin flounder nervous necrosis virus as well as red‐spotted grouper nervous necrosis virus genotype in shellfish

Cited by 19 publications

References 34 publications

Betanodavirus and VER Disease: A 30-year Research Review

Betanodavirus and VER Disease: A 30-year Research Review

Isolation and initial characterization of new betanodaviruses in shellfish

Complete genome sequence and pathogenic analysis of a new betanodavirus isolated from shellfish

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