title: An indirect enzyme-linked immunosorbent assay for the identification of antibodies to Senecavirus A in swine.
abstract: BACKGROUND
  Senecavirus A (SVA), a member of the family Picornaviridae, genus Senecavirus, is a recently identified single-stranded RNA virus closely related to members of the Cardiovirus genus. SVA was originally identified as a cell culture contaminant and was not associated with disease until 2007 when it was first observed in pigs with Idiopathic Vesicular Disease (IVD). Vesicular disease is sporadically observed in swine, is not debilitating, but is significant due to its resemblance to foreign animal diseases, such as foot-and-mouth disease (FMD), whose presence would be economically devastating to the United States. IVD disrupts swine production until foreign animal diseases can be ruled out. Identification and characterization of SVA as a cause of IVD will help to quickly rule out infection by foreign animal diseases.
  
  
  METHODS
  We have developed and characterized an indirect ELISA assay to specifically identify serum antibodies to SVA. Viral protein 1, 2 and 3 (VP1, VP2, VP3) were expressed, isolated, and purified from E. coli and used to coat plates for an indirect ELISA. Sera from pigs with and without IVD symptoms as well as a time course following animals from an infected farm, were analyzed to determine the antibody responses to VP1, VP2, and VP3.
  
  
  RESULTS
  Antibody responses to VP2 were higher than VP1 and VP3 and showed high affinity binding on an avidity ELISA. ROC analysis of the SVA VP2 ELISA showed a sensitivity of 94.2% and a specificity of 89.7%. Compared to IFA, the quantitative ELISA showed an 89% agreement in negative samples and positive samples from 4-60 days after appearance of clinical signs. Immune sera positive for FMDV, encephalomyocarditis virus, and porcine epidemic diarrhea virus antibodies did not cross-react.
  
  
  CONCLUSIONS
  A simple ELISA based on detection of antibodies to SVA VP2 will help to differentially diagnose IVD due to SVA and rule out the presence of economically devastating foreign animal diseases.
authors.affiliation: Department of Veterinary and Biomedical Sciences, University of Minnesota, 1971 Commonwealth Ave, St. Paul, MN, 55108, USA. dvora013@umn.edu.
authors.forename: Cheryl M T
authors.initials: CM
authors.lastname: Dvorak
authors.affiliation: Department of Veterinary and Biomedical Sciences, University of Minnesota, 1971 Commonwealth Ave, St. Paul, MN, 55108, USA.|Department of Virology, Ankara University, Faculty of Veterinary Medicine, Diskapi, 06110, Ankara, Turkey.
authors.forename: Zeynep
authors.initials: Z
authors.lastname: Akkutay-Yoldar
authors.affiliation: Department of Veterinary and Biomedical Sciences, University of Minnesota, 1971 Commonwealth Ave, St. Paul, MN, 55108, USA.
authors.forename: Suzanne R
authors.initials: SR
authors.lastname: Stone
authors.affiliation: Swine Vet Center P.A., 1608 S. Minnesota Ave, St. Peter, MN, 56082, USA.
authors.forename: Steven J P
authors.initials: SJ
authors.lastname: Tousignant
authors.affiliation: Department of Veterinary Population Medicine, University of Minnesota, 1365 Gortner Ave, St. Paul, MN, 55108, USA.
authors.forename: Fabio A
authors.initials: FA
authors.lastname: Vannucci
authors.affiliation: Department of Veterinary and Biomedical Sciences, University of Minnesota, 1971 Commonwealth Ave, St. Paul, MN, 55108, USA.
authors.forename: Michael P
authors.initials: MP
authors.lastname: Murtaugh
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood*; D003001:Cloning, Molecular; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods / Q000662:veterinary*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D019084:Fluorescent Antibody Technique, Indirect / Q000662:veterinary; D015967:Gene Expression Regulation, Viral; D010849:Picornaviridae / Q000276:immunology* / Q000302:isolation & purification; D010850:Picornaviridae Infections / Q000175:diagnosis / Q000662:veterinary* / Q000821:virology; D012680:Sensitivity and Specificity; D013552:Swine; D013553:Swine Diseases / Q000175:diagnosis / Q000821:virology*; D014764:Viral Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism
chemical_list: D000914:Antibodies, Viral; D014764:Viral Proteins
keywords: ELISA; Immunology; SVA; SVV; Seneca valley virus; Senecavirus A; Swine; Veterinary diagnostics