Genetic Characterization Of Porcine Epidemic Diarrhea Virus In China Between 2014 And 2018: Emergence Of The G1c Subtype

Porcine epidemic diarrhea virus (PEDV) has caused substantial economical loss to the Chinese swine industry. To illustrate the genetic characterization of PEDV circulating in China, 205 clinical samples between 2014 and 2018 were collected from 7 provinces in China 93.17% (191 of 205) of the intestinal and fecal samples were positive for PEDV. 25 S1 amino acid (aa) together with 27 ORF3 genes from 8 provinces were sequenced and analyzed. The phylogenetic trees based on the 51 and ORF3 genes were constructed by the neighbor joining method using MEGA 7 software. PEDV prevalence was 86.96% (40 of 46) of the swine farms in the 8 provinces and the PEDV positive rate was 93.17% (191 of 205) in the tested samples. Genetic analysis showed CH-JIANGXI-1-2016 CH-JIAGNXI-2-2016, CH-JIANGXI-3-2016 and CH-JIANGXI-2017 had three notable insertions or deletions occurred at aa 59-62, 160, and 139 (140) when compared to all of the strains in this study; moreover, phylogenetic analysis indicated that the four isolates formed a new branch significantly different from G1a, G1b and Indel subtype based on S1 gene: that is the G1c subtype. More research is needed to determine whether the insertions and deletions had biological influence on the virus. The results acquired in the present study showed the genetic diversity of PEDV circulating in 8 provinces, providing information for the development of new diagnostic methods and new vaccines. (C) 2020 PVJ. All rights reserved