Pathogenicity and immunogenicity of a new strain of porcine epidemic diarrhea virus containing a novel deletion in the N gene

Abstract

A B S T R A C TSince late 2010, highly virulent PEDV G2-genotype strains have emerged globally extracting heavy losses on the pork industries of numerous countries. We investigated the characteristics of a field strain of PEDV (PEDV strain SH) isolated from a piglet with severe diarrhea on a farm in Shanghai China. Whole genome sequencing and analysis revealed that the SH strain belonged to subtype G2b and has a unique 12-aa deletion (aa 399-410) including the antigenic epitope NEP-1C9 (aa 398-406) of the N protein. PEDV SH strain is highly pathogenic to challenged newborn piglets, resulting in 100 % morbidity and mortality. Pathological examination revealed significant villus atrophy in the jejuna of infected piglets. Mice inoculated with inactivated PEDV SH produced antibodies against the N protein, but no antibodies against the deletions. These results illustrated that deletion of the NEP-1C9 epitope had no effect on the immunogenicity or pathogenicity of PEDV, providing evidence of the necessity to monitor the genetic diversity of the virus. Our study also contributes to development of candidate for vaccines and diagnostics that could differentiate pigs seropositive due to vaccination by conventional strains from wild virus infection.

Study on the Characteristic Codon Usage Pattern in Porcine Epidemic Diarrhea Virus Genomes and Its Host Adaptation Phenotype

“…It can be seen that all 56 PEDV isolates were divided into two main phylogroups ( Figure 1 ), Group I (including G1a and G1b) and Group II (including G2a, G2b, and G2c). This was in agreement with the findings of previous reports showing two classical divergent clades ( Hsueh et al, 2020 ; Wang X.W. et al, 2020 ).…”

“…The only accessory protein ORF3 has ion channel activity ( Wang et al, 2012 ), and was found beneficial to virus proliferation ( Wang et al, 2012 ; Ye et al, 2015 ; Si et al, 2020 ). Phylogenetic analysis showed that PEDV could be divided into two genotypes (G1 and G2) and five subgenotypes (G1a, G1b, G2a, G2b, and G2c) based on complete sequence of S gene ( Fan et al, 2017 ; Hsueh et al, 2020 ; Wang H. et al, 2020 ; Wang X.W. et al, 2020 ).…”

Tomatidine inhibits porcine epidemic diarrhea virus replication by targeting 3CL protease

“…MK841495.1), SH (GenBank accession no. MK841494.1) [ 18 ], and CV777 (GenBank accession no. AF353511.1) strains were maintained in our laboratory and passaged in Vero cells with 2.5% trypsin.…”

Modulation of Innate Antiviral Immune Response by Porcine Enteric Coronavirus

“…It has been reported that M protein is involved in virion assembly, budding, and host innate immune induction ( Utiger et al, 1995 ). The PEDV N protein is a highly conserved protein that consists of 441aa and is involved in the survival of the virus ( Wang et al, 2020c ).…”