Background
The existing detection
Conclusions
This study established an efficient detection method with high sensitivity and specificity for the clinical diagnosis of PCV2 antigen, that will facilitate a rapid and convenient way to evaluate the infection status of vaccinated pigs.
Results
The truncated CAP protein (dCAP) was used to immunize rabbits to generate anti-serum. After preliminary purification by caprylic acid/ammonium sulfate precipitation (CAAS), specific PAbs were purified by affinity chromatography column coupled with dCAP and its titer was about two-fold higher than preliminary purified PAbs. Colloidal gold-PAbs conjugate was synthesized under the optimum conditions. The specific anti-dCAP PAbs and goat anti-rabbit antibody (GAR) were then sprayed onto nitrocellulose (NC) membrane as a test line (TL) and a control line (CL), respectively. The visual limit detection (vLOD) of the GICA strips was 5 ng/mL. Specificity assay indicated that the GICA strips had specifically detected PCV2 and was not reactive for porcine epidemic diarrhea virus (PEDV), pseudorabies virus (PRV), porcine reproductive and respiratory syndrome virus (PRRSV) or classic swine fever virus (CSFV). A total of 36 porcine serum samples were detected by this GICA and commercial enzyme-linked immunosorbent assay (ELISA) Kit, 9 positive samples were found by the developed strip with the rate of 25.0% comparing with 11 positive samples detected by the commercially ELISA Kit which positive rate was 30.5%, and the receiver operating characteristic (ROC) curve revealed that the relative sensitivity and specificity of this GICA strip were 72.7 and 96.0%, respectively, with an area of 87.2%. Conclusions: This study established an efficient detection method with high sensitivity and specificity for the clinical diagnosis of PCV2 antigen, that will facilitate a rapid and convenient way to evaluate the infection status of vaccinated pigs.