Comparative Characterization and Pathogenicity of a Novel Porcine Epidemic Diarrhea Virus (PEDV) with a Naturally Occurring Truncated ORF3 Gene Coinfected with PEDVs Possessing an Intact ORF3 Gene in Piglets
Ying Lu,
Weijian Huang,
Lian Zhong,
Yibin Qin,
Xueting Liu,
Chunjie Yang,
Ruomu Wang,
Xueli Su,
Chen Du,
Xue Mi,
Hejie Wang,
Ying He,
Wu Zhao,
Ying Chen,
Zuzhang Wei,
Kang Ouyang
Affiliations
Ying Lu
College of Animal Science and Technology, Guangxi University, Nanning 530005, China
Weijian Huang
College of Animal Science and Technology, Guangxi University, Nanning 530005, China
Lian Zhong
College of Animal Science and Technology, Guangxi University, Nanning 530005, China
Yibin Qin
Guangxi Veterinary Research Institute, Nanning 530005, China
Xueting Liu
College of Animal Science and Technology, Guangxi University, Nanning 530005, China
Chunjie Yang
College of Animal Science and Technology, Guangxi University, Nanning 530005, China
Ruomu Wang
College of Animal Science and Technology, Guangxi University, Nanning 530005, China
Xueli Su
College of Animal Science and Technology, Guangxi University, Nanning 530005, China
Chen Du
College of Animal Science and Technology, Guangxi University, Nanning 530005, China
Xue Mi
College of Animal Science and Technology, Guangxi University, Nanning 530005, China
Hejie Wang
College of Animal Science and Technology, Guangxi University, Nanning 530005, China
Ying He
Guangxi Veterinary Research Institute, Nanning 530005, China
Wu Zhao
Guangxi Veterinary Research Institute, Nanning 530005, China
Ying Chen
College of Animal Science and Technology, Guangxi University, Nanning 530005, China
Zuzhang Wei
College of Animal Science and Technology, Guangxi University, Nanning 530005, China
Kang Ouyang
College of Animal Science and Technology, Guangxi University, Nanning 530005, China
Coinfection caused by various genotypes of porcine epidemic diarrhea virus (PEDV) is a new disease situation. We previously reported the coexistence of PEDV strains containing different ORF3 genotypes in China. In this study, the PEDV strains 17GXCZ-1ORF3d and 17GXCZ-1ORF3c were isolated and plaque-purified from the same piglet, which had a natural large deletion at the 172–554 bp position of the ORF3 gene or possessed a complete ORF3 gene, respectively. Meanwhile, 17GXCZ-1ORF3d had >99% nt identity with 17GXCZ-1ORF3c in the 5′UTR, ORF1a/1b, S, E, M, N and 3′UTR regions but only demonstrated low nucleotide identities (80.5%) in the ORF3 gene. To elucidate the pathogenicity, 7-day-old piglets were infected. Piglets infected with these two PEDV strains exhibited severe clinical signs and shed the virus at the highest level within 96 hpi. Compared with the piglets inoculated with the 17GXCZ-1ORF3c strain, the piglets inoculated with the 17GXCZ-1ORF3d strain had higher mortality rates (75% vs. 50%), an earlier onset of clinical signs with a significantly higher diarrhea score, lower VH:CD ratios and a higher percentage of PEDV-positive enterocytes. This study is the first to report PEDV coinfections with different ORF3 genotypes, and a PEDV strain with a large deletion in the ORF3 gene might have the advantage of a potential genetic marker, which would be useful during vaccine development.
