DETECTION OF MAEDI-VISNA VIRUS-ANTIBODIES USING A SINGLE FUSION TRANSMEMBRANE-CORE P25 RECOMBINANT PROTEIN ELISA AND A MODIFIED RECEIVER-OPERATING CHARACTERISTIC ANALYSIS TO DETERMINE CUTOFF VALUES

The core p25 and transmembrane (TM) genes of Maedi-Visna virus (MVV) w ere cloned individually into the pGEX-2T expression vector. Both prote ins were expressed as a combined fusion protein in frame with glutathi one S-transferase (GST). The purified recombinant antigens (GST-TM and GST-TM-p25) were used to develop a MW ELISA. A preliminary assessment of the diagnostic potential of the recombinant antigens (GST-TM and G ST-TM-p25) was made by testing the antigens against 46 seropositive an d 46 seronegative sheep and comparing the results with a commercial p2 5 ELISA kit. A two-graph receiver operating characteristic (TG-ROC) an alysis program was used to interpret the data. The GST-TM-p25 ELISA wa s more sensitive than the commercial assay which is based on the p25 a ntigen alone and more specific than the GST-TM ELISA. Copyright (C) 19 97 Elsevier Science B.V.