[Development and application of real-time RT-PCR and S1 protein-based indirect ELISA for porcine deltacoronavirus]

Porcine deltacoronavirus (PDCoV) has been recently recognized as an emerging viral pathogen that causes diarrhea in newborn piglets. A total of 254 small intestinal or fecal samples collected from 10 provinces including Henan, Hunan, Zhejiang, Jiangxi, Anhui, Hebei, Heilongjiang, Jiangsu, Shandong and Shanghai between 2014 and 2015, were screened by quantitative RT-PCR targeting the viral M gene. Eleven PDCoV positive samples were identified with a total positive rate of 4.33%. An indirect enzyme-linked immunosorbent assay (ELISA) was developed based on the recombinant S1 protein of PDCoV. This assay was used to test 609 serum samples of pigs with diarrhea symptoms collected from 10 provinces between 2015 and 2016. The positive rate of PDCoV antibody was 44.17% (269/609). The two methods can be used to monitor the PDCoV epidemiology in the levels of PDCoV specific RNA or antibody, helping better prevent and control PDCoV.