Genetic diversity of perch rhabdoviruses isolates based on the nucleoprotein and glycoprotein genes

Abstract

Despite the increasing impact of rhabdoviruses in European percid farming, the diversity of the viral populations is still poorly investigated. To address this issue, we sequenced the partial nucleoprotein (N) and complete glycoprotein (G) genes of nine rhabdoviruses isolated from perch (Perca fluviatilis) between 1999 and 2010, mostly from France, and analyzed six of them by immunofluorescence antibody test (IFAT). Using two rabbit antisera raised against either the reference perch rhabdovirus (PRhV) isolated in 1980 or the perch isolate R6146, two serogroups were distinguished. Meanwhile, based on partial N and complete G gene analysis, perch rhabdoviruses were divided into four genogroups, A-B-D and E, with a maximum of 32.9% divergence (G gene) between isolates. A comparison of the G amino acid sequences of isolates from the two identified serogroups revealed several variable regions that might account for antigenic differences. Comparative analysis of perch isolates with other rhabdoviruses isolated from black bass, pike-perch and pike showed some strong phylogenetic relationships, suggesting cross-host transmission. Similarly, striking genetic similarities were shown between perch rhabdoviruses and isolates from other European countries and various ecological niches, most likely reflecting the circulation of viruses through fish trade as well as putative transfers from marine to freshwater fish. Phylogenetic relationships of the newly characterized viruses were also determined within the family Rhabdoviridae. The analysis revealed a genetic cluster containing only fish viruses, including all rhabdoviruses from perch, as well as siniperca chuatsi rhabdovirus (SCRV) and eel virus X (EVEX). This cluster was distinct from the one represented by spring viraemia of carp vesiculovirus (SVCV), pike fry rhabdovirus (PFRV) and mammalian vesiculoviruses. The new genetic data provided in the present study shed light on the diversity of rhabdoviruses infecting perch in France and support the hypothesis of circulation of these viruses between other hosts and regions within Europe.

Virus genomes and virus-host interactions in aquaculture animals

“…Spring viremia of carp virus (SVCV), an earlier identified rhabdovirus, causes infectious hemorrhagic septicemia in common carp (Cyprinus carpio) [102,113]. Perch rhabdovirus causes lethal hemorrhagic disease in different farmed species of perch, bass, grayling and trout [114,115]. Viral hemorrhagic septicemia virus (VHSV) and infectious haematopoietic necrosis virus (IHNV) are two typical rhabdoviruses of the Novirhabdovirus genus.…”

“…Through age calculations on six genes, the first bifurcation event of the isolates they analyzed was estimated to have occurred within the last 300 years. Additionally, comprehensive phylogenetic analyses have been performed by comparing the corresponding gene sequences of worldwide VHSV or IHNV isolates [114,119,120].…”

Characterization of perch rhabdovirus (PRV) in farmed grayling Thymallus thymallus

“…Therefore, new primer pairs oPVP116 (5'ACW TGT GAY TWC MGW TGG TAT GG3') and oPVP118 (5'CTG TTA GCT GTT TTT TTC ATA3'), and oPVP126 (5'GAT ATG AAA AAA ACT GCA ACA G3') and Rha-G-seqR2 (5'GAG GAG TCC TCT ATG TTG GTC3') were used in order to obtain the complete viral G gene sequence in 2 overlapping fragments. Primers oPVP116, oPVP118 and oPVP126 were published by Talbi et al (2011), and primer Rha-G-seqR2 was designed based on sequences obtained in this study. The expected amplicon size for primers oPVP116&oPVP118 was approximately 1400 bp (Talbi et al 2011) and for primers oPVP126&Rha-G-seqR2, it was 676 bp.…”

“…Primers oPVP116, oPVP118 and oPVP126 were published by Talbi et al (2011), and primer Rha-G-seqR2 was designed based on sequences obtained in this study. The expected amplicon size for primers oPVP116&oPVP118 was approximately 1400 bp (Talbi et al 2011) and for primers oPVP126&Rha-G-seqR2, it was 676 bp. The primers LF (5'CTC TGA TGT CAT GGG AAY TG3') and LR (5'CAT CCC AAC AGA CAA GCY TGT C3') were used to amplify a 399 bp fragment of the L gene.…”

“…More than 14 fish rhabdovirus species from both freshwater and marine fishes have been described (Mork et al 2004, Hoffmann et al 2005, Kuzmin et al 2009, Talbi et al 2011). The rhabdoviruses causing major epizootics are the novirhabdoviruses viral haemorrhagic septicaemia virus (VHSV) and infectious haematopoietic necrosis virus (IHNV) and the vesiculovirus causing spring viraemia of carp (SVCV).…”