The University of Georgia College of Veterinary Medicine

Georgia Veterinary Scholar Program

Georgia Veterinary Scholar	Faculty Mentor

Karen McKenzie TuskegeeUniversity Class of 2006	Dr. Mark Jackwood

Development of an ELISA test for Turkey Coronavirus

Turkey poult enteritis is a severe disease in commercial turkeys that has been recognized in North America as an important cause of economic loss. Clinical signs of turkey poult enteritis usually appear at 7 to 28 days of age and may consist of diarrhea, decreased feed efficiency, decreased weight gain, and uneven flock growth. The etiologic agent of this acute, highly contagious enteric disease is an enveloped single stranded RNA virus designated turkey coronavirus (TCoV). There is no mechanism to control TCoV. The virus is difficult to isolate and propagate in the laboratory. Difficulties propagating the virus have hindered the development of an effective diagnostic test. The goal of this project was to create a TCoV ELISA test using several strains of TCoV that have been adapted to grow to high titers in embryonating turkey eggs. To obtain sufficient antigen for coating ELISA plates, TCoV was propagated by inoculation of 18 to 23 days of age SPF embryonating turkey eggs and the intestines were harvested 72 hours after inoculation. Sucrose cushion ultracentrifugation was used to purify the virus and RT-PCR was used to detect the presence of viral RNA. Additionally, electron microscopy was used to verify the presence of intact virions. The ELISA test was optimized by coating ELISA plates with the purified virus and then using serially diluted known TCoV positive sera, negative control sera, and secondary anti-turkey IgG conjugate. Optimal concentrations of antigen were determined by a checkerboard titration and the sensitivity and specificity of the TCV ELISA was evaluated.