Publication Abstract

Genotyping spring viraemia of carp virus and other piscine vesiculo-like viruses using reverse hybridisation

By A.M.Sheppard, R-M Le Deuff and D.M.Stone

Spring viraemia of carp (SVCV) is a severe haemorrhagic rhabdovirus disease of cyprinids and is notifiable to the Office International des Epizooties (OIE). SVCV infected fish are subject to movement restrictions. Antigenically related viruses, which are currently non-notifiable have also been isolated from a number of other cyprinid species including grass carp (Ctenopharyngodon idella), tench (Tinca tinca), roach (Rutilus rutilus) and common bream (Abramis brama), and also from pike (Esox lucius). Phylogenetic analysis of a 550bp region of the glycoprotein gene has led to the grouping of SVCV and related viruses into four genogroups . Genogroup I the Rhabdovirus carpio group, comprising all of the isolates classified by serology as SVCV Genogroup II the Grass carp rhabdovirus group comprising a single isolate, previously identified as PFRV. Genogroup III, the Pike fry rhabdovirus group comprising of the original PFR isolate. Genogroup IV the Tench rhabdovirus group comprising the non-SVCV-non-PFR isolates (including some previously identified as PFR by serology) (Stone et al. 2003). It is often difficult however, to distinguish between these isolates using the serological assays currently recommended by the OIE (Ahne et al. 1998, Way et al. 1998, Rowley et al, 2001), raising concerns over the accurate identification of SVCV and the reliability of some SVC diagnoses. It is important therefore to develop methods robust enough to distinguish between SVCV and other fish rhabdoviruses. A reverse hybridisation technique modelled on a commercially available line probe assay (Innogenetics) is under development. Amplicons generated in a multiplex RT-PCR reaction are captured using immobilised genogroup specific probes and detected using a BCIP/NBT alkaline phosphatase substrate kit (BIO-RAD).

Reference:

A.M.Sheppard, R-M. Le Deuff, P.D. Martin, G. Woolford, K. Way and D.M.Stone (2007) Genotyping spring viraemia of carp virus and other piscine vesiculo-like viruses using reverse hybridisation. Diseases of Aquatic Organisms, 76(2): 163-168