Immunological and molecular diagnostic techniques in fish health: present and future prospectus.

Fish health management is critical to aquaculture and fisheries as it directly affects sustainability and productivity. Fish disease diagnosis has taken a massive stride because of advances in immunological and molecular diagnostic tools which provide a sensitive, quick, and accurate means of identifying diseases. This review presents an overview of the main molecular and immunological diagnostic methods for determining the health of fish.

Early viral uptake and host-associated immune response in the tissues of seven-band grouper following a bath challenge with nervous necrosis virus.

In the present study, early uptake of nervous necrosis virus (NNV) in the tissues (gill, brain, skin, eye, heart) and immune response associated with the uptake in the gill and brain of seven-band grouper was investigated. The gill was found to act as a primary portal of entry for NNV during the initial phase of the water-borne infection. The presence of viral genome and infectious particles was demonstrated using quantitative (qPCR, viral titer) and qualitative (ISH) approach.

Juvenile olive flounder immersed in live VHSV at 17 °C and 20 °C shows resistance against VHSV infection at 10 °C.

Viral hemorrhagic septicemia (VHS) causes serious economic loss in olive flounder aquaculture industry in Korea. Water temperature is known to play a critical role in VHS disease outbreak. Here, we assessed the potential efficacy of VHSV immersion treatment in relation to resistance conferred at differential water temperatures in olive flounder.

Functional characterization of seven-band grouper immunoglobulin like cell adhesion molecule, Nectin4 as a cellular receptor for nervous necrosis virus.

Nectin-4/PVRL4 belonging to the family of immunoglobulin-like cell adhesion molecules was identified as a potential cellular receptor for several animal viruses. Here we show that nervous necrosis virus that causes viral nervous necrosis in teleosts uses the same receptor in its life cycle. Transfection of SSN-1 cell lines with an expression vector encoding Nectin-4 rendered them to be more susceptible to NNV.

Nanoencapsulation of inactivated-viral vaccine using chitosan nanoparticles: Evaluation of its protective efficacy and immune modulatory effects in olive flounder (Paralichthys olivaceus) against viral haemorrhagic septicaemia virus (VHSV) infection.

Viral haemorrhagic septicaemia virus (VHSV), a (-) ssRNA virus belonging to the genus Novirhabdovirus of rhabdoviridae family, is the aetiological agent of viral haemorrhagic septicaemia (VHS) disease which causes huge economic losses in farmed olive flounder (Paralichthys olivaceus) and significant mortalities among several other marine fish species in Korea, Japan, and China. Previously, we developed an inactivated vaccine viz., formalin-inactivated VHSV mixed with squalene as adjuvant which was effective in conferring protective immunity (58-76% relative percentage survival) against VHSV but the mode of administration was intraperitoneal injection which is not feasible for small sized fingerling fish.

Kinetics of infectious virus and viral RNA copy number in the blood of olive flounder infected with viral hemorrhagic septicemia virus (VHSV).

Viral hemorrhagic septicemia (VHS) is a cold-water disease caused by viral hemorrhagic septicemia virus (VHSV) at an optimal temperature of 9 °C-15 °C. VHSV isolation and detection have been accomplished by using a number of diagnostic methods such as cell culture and qRT-PCR. Spleen and kidney have been reported as the main target organs of VHSV-infection; however, how VHSV spreads throughout the fish body has not been clearly studied.

PLGA encapsulated inactivated-viral vaccine: Formulation and evaluation of its protective efficacy against viral haemorrhagic septicaemia virus (VHSV) infection in olive flounder (Paralichthys olivaceus) vaccinated by mucosal delivery routes.

Viral haemorrhagic septicaemia virus (VHSV), an OIE listed viral pathogen, is the etiological agent of a contagious disease, causing huge economic losses in farmed olive flounder (Paralichthys olivaceus) and significant mortalities among several other marine fish species in Korea, Japan, and China. In continuation with our previous work, where injection vaccination with inactivated VHSV mixed with squalene (as adjuvant) conferred higher protective immunity to olive flounder, the present study focused on replacing the injection route of vaccine delivery by immersion/oral route to overcome the limitations of the parenteral immunization method. Here, we encapsulated the inactivated VHSV vaccine with PLGA (poly lactic-co-glycolic acid) nanoparticles (PNPs-IV) and evaluated its ability to induce protective immunity in olive flounder (12.

Development of an in-situ hybridization assay using riboprobes for detection of viral haemorrhagic septicemia virus (VHSV) mRNAs in a cell culture model.

An in situ hybridization (RNA-ISH) assay has been developed and optimized to detect viral haemorrhagic septicemia virus (VHSV), an OIE listed piscine rhabdovirus, in infected fish cells using fathead minnow (FHM) as a model cell line. Two antisense riboprobes (RNA probes) targeting viral transcripts from a fragment of nucleoprotein (N) and glycoprotein (G) genes were generated by reverse transcription polymerase chain reaction (RT-PCR) using VHSV specific primers followed by a transcription reaction in the presence of digoxigenin dUTP. The synthesized RNA probes were able to detect viral mRNAs in formalin fixed VHSV infected FHM cells at different time points post inoculation (pi).