Abstract
Porcine epidemic diarrhea (PED), caused by porcine epidemic diarrhea virus (PEDV), is a highly contagious, acute enteric viral disease of swine characterized by vomiting, watery diarrhea, dehydration and death. To identify and characterize the field PEDVs associated with the outbreaks of severe diarrhea in piglets in Jiangxi, 2013, the complete genome sequences of two representative strains of PEDV, designated CH/JX-1/2013 and CH/JX-2/2013, were determined and analyzed. The genome sequences of both emergent Jiangxi PEDV strains, CH/JX-1/2013 and CH/JX-2/2013, were 28,038 nucleotides in length excluding 3’ poly (A) tail. Compared to the PEDV CV777 strain, CH/JX-1/2013 and CH/JX-2/2013 had some unique genetic characteristics in the proximal region of the 5´-UTRs. Phylogenetic analysis of the complete genomes and the structural proteins revealed that CH/JX-1/2013 and CH/JX-2/2013 had a close relationship with post-2010 Chinese PEDV strains and US strains identified in 2013. The nucleotide identity between the two Jiangxi strains (CH/JX-1/2013 and CH/JX-2/2013) and 30 strains of PEDV identified ante-2010 and post-2010 ranged from 96.3–97.0% and 97.3–99.7%, respectively. Multiple nucleotide and deduced amino acid mutations were observed in the ORF1a/b, S, ORF3, E, M and N genes among the current field PEDV strains when compared to the CV777 strain. Some of the mutations altered the amino acid charge and hydrophilicity, and notably, there was an amino acid substitution in the middle of one neutralizing epitope (L1371I) of the S gene of both CH/JX-1/2013 and CH/JX-2/2013. Taken together, the accumulated genetic variations of the current field PEDV strains might have led to antigenic changes of the viruses, which might confer the less effectiveness or failure of the CV777-based vaccines currently being widely used in Jiangxi, China.
Highlights
Porcine epidemic diarrhea (PED) is a highly contagious, acute enteric viral disease of swine characterized by vomiting, watery diarrhea, and dehydration and has become a devastating issue in many pig-raising countries [1]
The results from the genome-wide comparative analysis showed that the nucleotide identity between the Jiangxi PED virus (PEDV) strains and strains identified post-2010 ranged from 97.3–99.7%, while the nucleotide identity with those determined ante-2010 (CV777, attenuated vaccine_KC189944, SM98, JS2008, JS2008new and LZC) ranged from 96.3–97.0% (S3 Table)
A total of 26 unique nucleotide substitutions were identified between two Jiangxi PEDV strains (CH/JX-1/2013 and CH/JX-2/2013) and 30 reference PEDV strains, which resulted in 14-aa changes, and most of them were located in ORF1a, ORF1b and S gene
Summary
Porcine epidemic diarrhea (PED) is a highly contagious, acute enteric viral disease of swine characterized by vomiting, watery diarrhea, and dehydration and has become a devastating issue in many pig-raising countries [1]. Outbreaks of PED with an increased severity of diarrhea, vomiting and dehydration have occurred in China since 2010, and the disease approached a mobility of as high as 100% and a mortality of 80–100% in piglets less than 10 days old, being recognized as a devastating illness causing death in neonatal piglets [11,12]. Unlike its intrinsic seasonal epidemics ever seen before 2010, the PED prevalent in Jiangxi in 2013 has emerged all year round even in the midst of summer, and much worse, some of pig-raising farms repeatedly got affected from the disease, resulting in massive deaths of neonatal piglets. In this study, we attempted to reveal the molecular characterizations of the PEDV strains currently circulating in Jiangxi, China and elucidate their phylogenetic relationship with PEDV vaccine strains and other reference strains
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
