Isolation of a novel mycovirus OMIV in Pleurotus ostreatus and its detection using a triple antibody sandwich-ELISA

A novel mycovirus was isolated from a diseased mushroom, Pleurotus ostreatus, using a purification procedure involving polyethylene glycol (PEG)–NaCl precipitation, differential centrifugation, and equilibrium centrifugation in a CsCl gradient. The virion was a 43 nm isometric virus encapsulating double-stranded RNA (dsRNA) genome of 2.1, 2.0, 1.9, and 1.7 kbp with a coat protein (CP) of 58 kDa. The new mycovirus was named Oyster Mushroom Isometric Virus (OMIV). A triple antibody sandwich-ELISA (TAS-ELISA) system was constructed to detect OMIV in the mushroom using an anti-OMIV mouse monoclonal antibody and an anti-OMIV rabbit polyclonal serum. The TAS-ELISA system was sensitive enough to allow detection of OMIV in the mushroom with the naked eye. It detected successfully virus particles from 0.6 mg of diseased tissue as well as 0.4 μg/ml purified virus preparation.