Preparation of monoclonal antibody against Macrobrachium rosenbergii Nodavirus and application of TAS-ELISA for virus diagnosis in post-larvae hatcheries in east China during 2000–2004

“Whitish muscle disease” of Macrobrachium rosenbergii, also called “whitish disease” or “white tail disease”, is a new serious epizootic disease that has occurred in recent years in giant freshwater prawn culture regions, mainly in southern China. This disease occurred in post-larvae 3–5 days to 3 weeks after desalting. Clinical signs include the development of white spot in muscles or milky muscles throughout the body, causing serious loss in few days, with a mortality rate of 40–90%. A 26–27 nm icosahedral non-enveloped virus, identified as M. rosenbergii Nodavirus (MrNV), was confirmed as the aetiological agent. Twelve hybridomas strongly secreting monoclonal antibodies (Mabs) against MrNV were shown to be specific for MrNV and reacted with MrNV 42 kDa coat protein by Western blot. A triple antibody enzyme-linked immunosorbent assay (TAS-ELISA) was developed and shown to be a useful diagnostic tool for MrNV infection.