Development of an indirect enzyme-linked immunosorbent assay (ELISA) to differentiate antibodies against wild-type porcine reproductive and respiratory syndrome from the vaccine strain TJM-F92 based on a recombinant Nsp2 protein

• Published in: Journal of virological methods Vol. 251; pp. 151 - 154
• Main Authors: Wang, X.X., Wang, F.X., Li, Z.G., Wen, Y.J., Wang, X., Song, N., Wu, H.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01-01-2018
• Subjects: Animals; Antibodies, Viral - blood; Antigens, Viral - genetics; Antigens, Viral - immunology; Continuous deletion protein; DIVA; ELISA; Enzyme-Linked Immunosorbent Assay - methods; Nsp2; Porcine respiratory and reproductive syndrome virus - immunology; PRRSV; Recombinant Proteins - genetics; Recombinant Proteins - immunology; Sensitivity and Specificity; Swine; Viral Nonstructural Proteins - genetics; Viral Nonstructural Proteins - immunology; Viral Vaccines - immunology; Continuous deletion protein; DIVA; Nsp2; PRRSV; ELISA
• ISSN: 0166-0934; 1879-0984
• DOI: 10.1016/j.jviromet.2017.09.001

•An ELISA based on the PRRSV modified live vaccine (MLV) TJM-F92 deletion on the Nsp2 was developed.•It distinguishes pigs infected with wild type strains from those vaccinated with MLV TJM-F92.•It has a sensitivity of a sensitivity of 90.7% (98/108) and a specificity of 95.1% (154/162).
An accurate ELISA method to differentiate pigs infected with wild-type porcine reproductive and respiratory syndrome (PRRSV) strains from vaccinated ones would help to monitor PRRSV vaccination compliance. The recombinant protein GST-d120aa derived from the continuous deletion of 120 amino acids in the non-structural protein 2 region of the modified-live vaccine strain TJM-F92 was used to develop an indirect enzyme-linked immunosorbent assay (d120-ELISA) for differentiating serum antibodies against TJM-F92 from other PRRSV strains. At the optimized cut-off value which was calculated at an S/P of 0.25, it yielded a sensitivity of 90.7% and a specificity of 95.1%. Cross-reactivity tests suggested that the d120-ELISA was PRRSV-specific. Coefficient of variations of the repeatability tests ranged between 1.41–17.02%. The results suggest that the d120-ELISA is suitable for differentiating animals infected with wild-type strains from those immunized with MLV TJM-F92.