Evidenziazione e caratterizzazione di Betanodavirus in specie ittiche selvatiche nel mare di Sicilia

Betanodavirus infection is responsible of the Viral Encephalopathy and Retinopathy (VER) a serious, worldwide fish disease. This virus can infect more than 34 species of fish and the epidemiological role of different fish species needs to be investigated. In the Mediterranean Sea nervous symptoms and mortality due to Betanodavirus infection are observed mainly in European sea bass farm (Dicentrarchus labrax), while very rarely symptoms are observed in wild fish. Diagnosis of virus infection in wild animals is thus relevant as well as the investigation about their possible role as reservoir or carrier. In this study we report the results of diagnostic tests performed on 73 brain samples from several fish species collected from Sicily. All the samples were tested by SSN-1 cell cultures isolation. Thirty one samples collected from wild Mullus barbatus, Gobius niger, Pagellus erythrinus, Trisopterus minutus capelanus and Sardina pilchardus showed a specific CPE on cell culture and Betanodavirus infection was confirmed by RT PCR and sequencing. Furthermore sequencing and phylogenetic analysis evidenced that Betanodavirus involved in the infection were Redspotted Grouper Nervous Necrosis Virus (RGNNV) and that wild strains had high genetic identity with strains collected in affected farmed fish, making us suppose an important role of carrier for wild fish.