title: Sensitive glycoprotein gIII blocking ELISA to distinguish between pseudorabies (Aujeszky's disease)-infected and vaccinated pigs.
abstract: A blocking enzyme-linked immunosorbent assay (ELISA) test has been developed to distinguish pseudorabies virus (PRV) (Aujeszky's disease virus) -infected pigs from those immunized with a glycoprotein g92 (gIII) deletion mutant, PRV (dlg92dltk) [OMNIMARK-PRV]. This blocking ELISA test utilizes an anti-PRV gIII monoclonal antibody (mAbgIII)-horseradish peroxidase (HRPO) conjugate, TMB for color development and a cloned PRVg92 (gIII) antigen to coat wells of microtiter test plates. Undiluted sera are used to block the binding of the mAbgIII-HRPO conjugate to the antigen. The gIII blocking ELISA is specific and has a sensitivity comparable to screening ELISA and latex agglutination tests. PRV-negative sera and sera from pigs vaccinated once, twice, or four times with the gIII-negative vaccine all showed negative S/N values of greater than 0.70 (S/N defined as the optical density at 630 nm of test sera/optical density at 630 nm of negative control sera). Sera from PRV-infected herds, sera from pigs experimentally infected with virulent PRV, and sera from pigs vaccinated with modified-live or inactivated gIII+ vaccines were positive for gIII antibodies (S/N less than 0.7). Sera from pigs experimentally infected with 200 PFU virulent PRV seroconverted to gIII+ antibodies 7-10 days postinfection. Sera from pigs vaccinated with gpX- and gI- vaccines seroconverted to gIII+ antibodies 7-8 days after vaccination. The gIII antibodies persisted after gIII+ vaccinated for at least 376 days postvaccination. Sera from pigs protected by vaccination with PRV (dlg92dltk) and then challenge exposed to virulent PRV at 21 days postvaccination showed gIII+ antibodies by 14 days postchallenge. The specificity and sensitivity of the gIII blocking ELISA assay was further demonstrated on the United States Department of Agriculture-National Veterinary Services Laboratory (USDA-NVSL) sera from the 1988 PRV check set and the 1989 gIII PRV check set by comparing the gIII blocking ELISA assay with virus neutralization, screening/verification ELISA and latex agglutination assays.
authors.affiliation: NovaGene Inc, Houston, TX 77030.
authors.forename: M
authors.initials: M
authors.lastname: Kit
authors.forename: S
authors.initials: S
authors.lastname: Kit
mesh_terms: D000818:Animals; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary*; D011558:Herpesvirus 1, Suid / Q000276:immunology; D007841:Latex Fixation Tests / Q000662:veterinary; D009500:Neutralization Tests / Q000662:veterinary; D011557:Pseudorabies / Q000175:diagnosis* / Q000276:immunology; D013552:Swine; D013553:Swine Diseases / Q000175:diagnosis* / Q000276:immunology; D014611:Vaccination / Q000662:veterinary; D014759:Viral Envelope Proteins / Q000276:immunology*
chemical_list: D014759:Viral Envelope Proteins; C042966:pseudorabies virus glycoproteins