Detection of PED virus by the immunoelectron microscopy and immunogold conjugate immunoelectron microscopy

면역전자현미경(免疫電子顯微鏡)(IEM) 기법(技法) 및 immunogold conjugate 면역전자현미경(免疫電子顯微鏡)(IGC-IEM) 기법(技法)을 이용(利用)한 돼지 분변내 PED 바이러스의 검출(檢出)

Both immunoelectron microscopy(IEM) and immunogold conjugate immunoelectron microscopy (IGC-IEM) techniques were developed for the detection of porcine epidemic diarrhea virus(PEDV) from the feces. Fecal samples were incubated sequentially with anti-PEDV monoclonal antibody(MoAb) and immunogold conjugated goat anti-mouse IgG+IgM. Then negatively stained, mounted on the formvar carbon-coated copper EM grids and observed by the transmission electron microscope. By the direct electron microscopy(DEM), coronavirus particles were observed from 17 cases of total 33 fecal samples of grower pigs and sows. The virons of coronavirus were moderately pleomorphic but mostly spherical, with a diameter ranged from 90 to 190nm. PED virus particles were identified from 15 cases of 17 DEM positive samples by the IEM and IGC-IEM techniques. Aggregates of PED virus coated with specific antibody were seen in fecal samples incubated with homologous anti-PED virus MoAb but not in control samples incubated with anti-TGE virus MoAb. Following incubation with immunogold-conjugated secondary antibody, the gold granules were usually distributed around and among the virus particles and soluble and viral particle-associated antigen. So, IEM and IGC-IEM techniques were proved a rapid and sensitive methods for detection and identification of PED virus from fecal and intestinal contents.