CONFIRMATION OF ANTIBODIES TO PRRSV BY RECOMBINANT ANTIGENS

Authors: Kwang, Hwei Sing; Yang, Xiao; OSORIO, FERNANDO - UNIVERSITY OF NEBRASKA; SUR, J - UNIVERSITY OF NEBRASKA; Lager, Kelly; Laegreid, William; WHITE, AMY - UNIVERSITY OF NEBRASKA; DOSTER, ALAN - UNIVERSITY OF NEBRASKA; Ross, Gary; WU, C - PURDUE UNIVERSITY

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 5/15/1997
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: An ELISA which uses PRRSV antigen grown in tissue culture cells has been developed for the sero-diagnosis of PRRSV infection in pigs. However, the whole-virus ELISA, due to absence or insufficient quantity of ORFs 4 and 5 antigens, gives an underestimation of the antibody directed against these antigens, which may lead to false-negative results. The production of viral proteins using recombinant DNA technology could provide an abundant source of individual viral antigens for carrying out such studies. Our previous work showed that antibodies to ORFs 5 and 6 appeared to be the 2 major serological markers in PRRSV infected pigs. In this study, the sensitivity and specificity of recombinant ORFs 5 and 6 used in the Western blotting assay for the confirmation of PRRS antibodies were evaluated. In addition, the recombinant assays were compared with a ELISA test for PRRS using 1) sequential sera obtained from 24 experimentally infected pigs; 2) naturally infected pig sera (n=20); 3) sera submitted to 3 State diagnostic laboratories (n=200); and 4) PRRS antibody negative reference sera (n=80). The recombinant assay yielded an average increased sensitivity of 10% over commercial ELISA test. The negative control (group 4 sera) showed no difference between the 2 assays. This comparison confirmed that the recombinant assay was more sensitive than the commercial ELISA test and is well suited for routine confirmation of the presence of PRRS virus antibodies.