Comparison of immune electron microscopy and genome electropherotyping techniques for detection of turkey rotaviruses and rotaviruslike viruses in intestinal contents

Seventy-nine intestinal contents specimens from 65 turkey flocks were examined for rotavirus and rotaviruslike virus (RVLV) by immune electron microscopy (IEM) and genome electropherotyping. The IEM procedure was slightly more sensitive in detecting these viruses; 7 of 48 specimens (14.6%) positive for virus by IEM were negative by the genome electropherotyping technique. The genome electropherotyping technique more readily differentiated the rotaviruses and RVLVs than did the IEM procedure; 15 of 48 specimens (31%) positive for virus by IEM could not be differentiated into rotavirus of RVLV, whereas only 4 of the 41 specimens (9.7%) positive by genome electropherotyping produced incomplete genome electropherotypes and could not be differentiated. Thirty-one specimens negative by IEM were also negative by genome electropherotyping. Specimens determined to contain only rotavirus by IEM produced only rotavirus genome electropherotypes. Likewise, specimens determined to contain RVLV alone by IEM produced only RVLV genome electropherotypes. Three specimens contained viruses morphologically resembling rotaviruses that were not aggregated by either the anti-turkey rotavirus serum or the anti-turkey RVLV serum and possessed genome electropherotypes distinct from those of the turkey rotavirus and RVLV. These rotaviruses may represent a third, previously unrecognized serogroup of turkey rotaviruses.