Establishment and Application of an Indirect ELISA Based on Recombinant S1 Protein for the Detection of Antibodies against Porcine Deltacoronavirus

Abstract

This study was conducted to understand porcine deltacoronavirus (PDCoV) epidemic situation, and provide a tool for PDCoV serum antibody detection and the epidemiological investigation. Prokaryotic expression of recombinant PDCoV partial spike (S) protein was used as detection antigen, and an indirect ELISA antibody detection method based on PDCoV S1 protein was established. The method was used to detect 570 serum samples collected from some pig farms in Hebei from January to December 2017. The results showed that the established ELISA method of PDCoV IgG antibody in this study could specifically detect PDCoV antibody; no cross-reaction with antisera against porcine epidemic diarrhea virus (PEDV), transmissible gastroenteritis virus (TGEV), porcine circovirus type 2 (PCV2), porcine reproductive and respiratory syndrome virus (PRRSV), classical swine fever (CSF) and pseudorabies virus (PRV) was found. The coefficients of variation (CV) of repeated in-batch test was 1.9%-5.4%, CV of batch-to-batch test was 2.3%-5.1%. In 570 blood samples, 105 were positive, and the positive rate was 18.4% (105/570), which was higher than the positive rate of PDCoV IgG antibody (11%) in Hebei from January 2016 to October 2016. It is suggested that the infection rate of PDCoV in Hebei is on the rise. The ELISA method established in this study had the advantages of high sensitivity, strong specificity and good reproducibility, and can be used for the detection of clinical PDCoV serum antibodies.Copyright © 2019, Chinese Journal of Animal Science and Veterinary Medicine Co., Ltd. All right reserved.