Viral Encephalopathy and Retinopathy in groupers (Epinephelus spp.) in southern Italy: a threat for wild endangered species?

BMC Veterinary Research

Giovanni Cattoli¹  Calogero Terregino¹  Antonio Terlizzi²  Perla Tedesco²  Elisabetta Cappellozza¹  Valentina Panzarin¹  Anna Toffan¹  Pierpaolo Patarnello⁴  Niccolò Vendramin³ 

[1] Istituto Zooprofilattico Sperimentale delle Venezie, viale dell’Università, 10-35020, Legnaro, Padova, Italy;Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, Università del Salento, CoNISMa, Lecce, Italy;Current affiliation: EURL for fishdiseases, DTU VET, Hangovej 2, Aarhus, Denmark;Fish Patologist, Private Expert, Istituto Zooprofilattico Sperimentale delle Venezie, viale dell’Università, 10 -35020 Legnaro, Padova, Italy

关键词: Epinephelus spp.;    Wild fish;    Neurological signs;    Betanodavirus;    Viral Encephalopathy and Retinopathy;   

Others  :  1119618
DOI  :  10.1186/1746-6148-9-20

 received in 2012-09-28, accepted in 2012-12-06,  发布年份 2013

【 摘 要 】

Background

Betanodaviruses are the causative agents of Viral Encephalopathy and Retinopathy (VER). To date, more than 50 species have proved to be susceptible and among them, those found in genus Epinephelus are highly represented. Clinical disease outbreaks are generally characterized by typical nervous signs and significant mortalities mainly associated with aquaculture activities, although some concerns for the impact of this infection in wild fish have been raised. In this study, the authors present the first documented report describing an outbreak of VER in wild species in the Mediterranean basin.

Case presentation

In late summer - early winter 2011 (September-December), significant mortalities affecting wild Dusky grouper (Epinephelus marginatus), Golden grouper (Epinephelus costae) and European sea bass (Dicentrarchus labrax) were reported in the municipality of Santa Maria di Leuca (Northern Ionian Sea, Italy). The affected fish showed an abnormal swimming behavior and swollen abdomens. During this epizootic, five moribund fish showing clear neurological signs were captured and underwent laboratory investigations. Analytical results confirmed the diagnosis of VER in all the specimens. Genetic characterization classified all betanodavirus isolates as belonging to the RGNNV genotype, revealing a close genetic relationship with viral sequences obtained from diseased farmed fish reared in the same area in previous years.

Conclusion

The close relationship of the viral sequences between the isolates collected in wild affected fish and those isolated during clinical disease outbreaks in farmed fish in the same area in previous years suggests a persistent circulation of betanodaviruses and transmission between wild and farmed stocks. Further investigations are necessary to assess the risk of viral transmission between wild and farmed fish populations, particularly in marine protected areas where endangered species are present.

【 授权许可】

   
2013 Vendramin et al.; licensee BioMed Central Ltd.

【 图 表 】

Figure 1.

Figure 2.

Figure 3.

【 参考文献 】

• [1]Mori K, Nakai T, Muroga K, Arimoto M, Mushiake K, Furusawa I: Properties of a new virus belonging to Nodaviridae found in larval striped jack (Pseudocaranx dentex) with nervous necrosis. Virol 1992, 187:368-371.
• [2]Fenner BJ, Thiagarajan R, Khen Chua H, Kwang J: Betanodavirus B2 is an RNA interference antagonist that facilitates intracellular viral RNA accumulation. J Virol 2006, 80:85-94.
• [3]Nishizawa T, Furuhashi M, Nagai T, Nakai T, Muroga K: Genomic classification of fish nodaviruses by molecular phylogenetic analysis of the coat protein gene. Appl Environ Microbiol 1997, 63:1633-1636.
• [4]Johansen R, Sommerset I, Tørud B, Korsnes K, Hjortaas MJ, Nilsen F, Nerland AH, Dannevig BH: Characterization of nodavirus and viral encephalopathy and retinopathy in farmed turbot Scophthalmus maximus (L.). J Fish Dis 2004, 27:591-601.
• [5]Panzarin V, Fusaro A, Monne I, Cappellozza E, Patarnello PP, Capua I, Holmes CH, Cattoli G: Molecular epidemiology and evolutionary dynamics of betanodavirus in southern Europe. Infect Genet Evol 2012, 12:63-70.
• [6]Olveira JG, Souto S, Dopazo CP, Thiéry R, Barja JL, Bandin I: Comparative analysis of both genomic segments of betanodaviruses isolated from epizootic outbreaks in farmed fish species provides evidence for genetic reassortment. J General Virol 2009, 90:2940-2951.
• [7]Toffolo V, Negrisolo E, Maltese C, Bovo G, Belvedere P, Colombo L, Dalla Valle L: Phylogeny of betanodaviruses and molecular evolution of their RNA polymerase and coat proteins. Mol Phylogenet Evol 2007, 43:298-308.
• [8]Bandín I, Dopazo CP: Host range, host specificity and hypothesized host shift events among viruses of lower vertebrates. Vet Res 2011, 42(1):67. BioMed Central Full Text
• [9]Lin CS, Lu MW, Tang L, Liu W, Chao CB, Lin CJ, Krishna NK, Johnson JE, Sheneemann A: Characterization of virus-like particles assembled in a recombinant baculovirus system expressing the capsid protein of fish nodavirus. Virol 2001, 290:50-58.
• [10]Chi SC, Lee KW, Hwang SJ: Investigation of host range of fish nodavirus in Taiwan. In Proceeding of the Tenth International Conference of the European Association of Fish Pathologists: 9–14 September 2001; Dublin. 21st edition. Aberdeen, Scotland: Albion Press; 40:49.
• [11]Hsiao-Che K, Ting-Yu W, Peng-Peng C, Young-Mao C, Hui-Ching C, Tzong-Yueh C: Real-time quantitative PCR assay for monitoring of nervous necrosis virus infection in grouper aquaculture. Clin Microbiol 2011, 49:1090-1096.
• [12]Marino G, Azzurro E: Nodavirus in dusky grouper Epinephelus marginatus, (Lowe 1834) of the Natural Marine Reserve of Ustica, South Thyrrenian sea. Biol Mar Medit 2001, 8:837-841.
• [13]Maltese C, Antonetti P, Quartesan R, Ormelli S, Borghesan F, Manfrin A, Selli L, Castiglione F, Ferrantelli V, Guercio A, Bovo G: Isolation of viral encephalopathy and retinopathy virus (VERV) from wild marine fish species in the Mediterranean sea. In Proceeding of the Twelfth International Conference Diseases of Fish and Shellfish, European Association of Fish Pathologists, 11–16 September 2005; Copenhagen. Aberdeen: Albion Press; 2005:8-19.
• [14]Ciulli S, Galletti E, Grodzki M, Alessi A, Battilani M, Prosperi S: Isolation and genetic characterization of Betanodavirus from wild marine fish from the adriatic Sea. Vet Res Commun 2007, 31:221-224.
• [15]Ucko M, Colorni A, Diamant A: Nodavirus infections in Israeli mariculture. J Fish Dis 2004, 27:459-469.
• [16]Zabala M, Louisy P, Garcia-Rubies A, Gracia V: Socio-behavioural context of reproduction in the Mediterranean dusky grouper Epinephelus marginatus (Lowe, 1834) (Pisces, Serranidae) in the Medes Islands marine reserve (NW Mediterranean, Spain). Sci Mar 1997, 61:79-98.
• [17]Panzarin V, Patarnello P, Mori A, Rampazzo E, Cappellozza E, Bovo G, Cattoli G: Development and validation of a real-time TaqMan PCR assay for the detection of betanodavirus in clinical specimens. Arch Virol 2010, 155:1193-1203.
• [18]Frerichs GN, Rodger HD, Peric Z: Cell culture isolation of piscine neuropathy nodavirus from juvenile sea bass, Dicentrarchus labrax. J General Virol 1996, 77:2067-2071.
• [19]Tamura K, Dudley J, Nei M, Kumar S: MEGA4: molecular evolutionary genetics analysis (MEGA) software version 4.0. Mol Biol Evol 2007, 24:1596-1599.
• [20]Breuil G, Bonami JR, Pepin JF, Pichot Y: Viral infection (picorna-like virus) associated with mass mortalities in hatchery-reared sea-bass (Dicentrarchus labrax) larvae and juveniles. Aquaculture 1991, 97:109-116.
• [21]Chérif N, Thiéry R, Castric J, Biacchesi S, Brémont M, Thabti F, Limem L, Hammami S: Viral encephalopathy and retinopathy of Dicentrarchus labrax and Sparus aurata farmed in Tunisia. Vet Res Commun 2009, 33:345-353.
• [22]Terlizzi A, Tedesco P, Patarnello P: Spread of Pathogens from Marine Cage Aquaculture - A Potential Threat for Wild Fish Assemblages Under Protection Regimes? In Health and Environment in Aquaculture. Edited by Carvalho ED, David GS, Silva RJ. Printed in Croatia: InTech, Janeza Trdine 9, 51000 Rjieka, Croatia; 2012:403-414.
• [23]Le Breton A, Grisez L, Sweetman J, Ollevier F: Viral nervous necrosis (VNN) associated with mass mortalities in cage-reared sea bass, Dicentrarchus labrax (L.). J Fish Dis 1997, 20:145-151.
• [24]Gomez DK, Matsuoka S, Mori K, Okinaka Y, Park SC, Nakai T: Genetic analysis and pathogenicity of betanodavirus isolated from wild redspotted grouper Epinephelus akaara with clinical signs. Arch Virol 2009, 154:343-346.