Isolation in cell culture and detection by PCR-based technology of IPNV-like virus from leucocytes of carrier turbot, Scophthalmus maximus (L.)

A non-destructive procedure was utilized to determine the infectious pancreatic necrosis virus (IPNV) status of an apparently healthy turbot broodstock. Blood samples were used to detect IPNV by reverse transcriptase-polymerase chain reaction (RT-PCR), Southern blot hybridization and nested PCR. In addition, viral isolation from turbot leucocytes was performed. Around 22% of the fish were IPNV positive by RT-PCR, and this increased to close to 60% when nested PCR was performed. The present report supports the use of blood samples for the detection of IPNV-like viruses in brood fish. In addition, we demonstrate that it is possible to isolate the virus from the blood of carrier fish, as a non-lethal detection method, although it is much less sensitive than RTPCR and nested PCR as a IPNV-like strain was isolated from only five of the 15 blood sample pools assayed. The viral isolate was identified as type Dry Mills (genogroup 1) by means of restriction fragment length polymorphisms and DNA sequencing.