Viral replication in excised fin tissues (VREFT) corresponds with prior exposure of Pacific herring, Clupea pallasii (Valenciennes), to viral haemorrhagic septicaemia virus (VHSV)

• Published in: Journal of fish diseases 2011, Vol.34 (1), p.3-12
• Main Authors: Grady, C.A, Gregg, J.L, Wade, R.M, Winton, J.R, Hershberger, P.K
• Format: Article
• Language: English
• Subjects: Animal Fins - virology; Animals; Clupea; Clupea pallasii; Culture Techniques - veterinary; Disease Susceptibility - veterinary; fin explant; fins; Fish Diseases - immunology; Fish Diseases - virology; Fishes; Hemorrhagic Septicemia, Viral; herd immunity; herring; Marine; Novirhabdovirus - immunology; Novirhabdovirus - physiology; Pacific herring; Rhabdoviridae Infections - immunology; Rhabdoviridae Infections - veterinary; Rhabdoviridae Infections - virology; viral haemorrhagic septicaemia virus; Viral hemorrhagic septicemia virus; Viral Plaque Assay - methods; viral replication in excised fin tissues; virion; Virus Replication; viruses
• ISSN: 0140-7775; 1365-2761
• DOI: 10.1111/j.1365-2761.2010.01210.x

Procedures for a viral replication in excised fin tissue (VREFT) assay were adapted to Pacific herring, Clupea pallasii, and optimized both to reduce processing time and to provide the greatest resolution between naïve herring and those previously exposed to viral haemorrhagic septicaemia virus (VHSV), Genogroup IVa. The optimized procedures included removal of the left pectoral fin from a euthanized fish, inoculation of the fin with >10⁵ plaque‐forming units (PFU) mL⁻¹ VHSV for 1 h, rinsing the fin in fresh medium six times to remove unadsorbed virions, incubation of the fin in fresh medium for 4 days and enumeration of the viral titre in a sample of the incubation medium by plaque assay. The optimized VREFT assay was effective at identifying the prior exposure history of laboratory‐reared Pacific herring to VHSV. The geometric mean VREFT value was significantly greater (P