Molecular detection and phylogenetic analysis of Cyprinid herpesvirus 3 in Brazilian ornamental fish

Cyprinid herpesvirus 3 has a worldwide distribution and presents high mortality rates in species of Cyprinus carpio, causing serious economic loss to the global aquaculture industry. The description of this infection in other ornamental fish species is still limited. For this purpose, 100 ornamental fish from 24 different species were tested by PCR for Cyprinid hespesvirus 3 and the positive samples represented 6% of the tested samples. Phylogenetic reconstruction, based on the Thymidine Kinase gene, revealed the existence of two distinct clades. One clade grouped a Brazilian sample with European and Asian genotypes of CyHV-3 and a second clade, containing only Brazilian sequences described in this study. All of the Brazilian sequences showed identity values greater than 97.7% when compared to each other. This is the first report of the occurrence of Cyprinid herpesvirus 3 in ornamental fish species in Brazil. These results in association with further studies of viral isolation and characterization can help in establishing effective surveillance and disease control program.