Porcine Epidemic Diarrhea Virus Shedding and Antibody Response in Swine Farms: A Longitudinal Study

Porcine epidemic diarrhea virus(PEDV) mainly infects neonatal pigs, resulting in significant morbidity and mortality. Owing to problems such as long periods of virus shedding, existing vaccines cannot provide complete protection from PEDV infection. The PEDV genome encodes two polyprotein precursors required for genome replication and transcription. Each polyprotein undergoes extensive proteolytic processing, resulting in functional subunits. This process is mainly mediated by its genome-encoded main protease, which is an attractive target for antiviral drug design. In this study, the main protease ofPorcine epidemic diarrhea virusin complex with a Michael acceptor was crystallized. The complex crystals diffracted to 2.5 Å resolution and belonged to space groupR3, with unit-cell parametersa= 175.3,b= 175.3,c= 58.7 Å. Two molecules were identified per asymmetric unit.

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Analysis of the spike, ORF3, and nucleocapsid genes of porcine epidemic diarrhea virus circulating on Thai swine farms, 2011–2016

PeerJ ◽

10.7717/peerj.6843 ◽

2019 ◽

Vol 7 ◽

pp. e6843 ◽

Cited By ~ 2

Author(s):

Supansa Tuanthap ◽

Sompong Vongpunsawad ◽

Cherdpong Phupolphan ◽

Ausanee Duang-in ◽

Suphot Wattanaphansak ◽

...

Keyword(s):

Porcine Epidemic Diarrhea Virus ◽

Phylogenetic Analyses ◽

Sequence Divergence ◽

Economic Loss ◽

Nucleotide Sequencing ◽

Swine Industry ◽

N Protein ◽

Diarrhea Virus ◽

Swine Farms ◽

Porcine Epidemic Diarrhea

Porcine epidemic diarrhea virus (PEDV) outbreaks on pig farms have caused significant economic loss in the swine industry since it was first reported in Thailand a decade ago. Anecdotal evidence suggests that PEDV is now endemic in this region, therefore genome information of circulating PEDV is important for molecular surveillance and evaluation of potential benefits of field vaccination. Here, we characterized PEDV infection on commercial Thai swine farms by screening 769 samples of feces and small intestinal contents from pigs with diarrhea between 2011 and 2016. Using reverse-transcription polymerase chain reaction targeting the spike (S) gene, 153 PEDV-positive samples were further subjected to analysis of the open reading frame 3 and nucleocapsid (N) genes. Comparison of 95 samples in which nucleotide sequencing was successfully obtained for all three genes revealed evolutionary diversity among the Thai PEDV strains. Phylogenetic analyses suggest that although some Thai strains changed little from years past, others resembled more closely to the recent strains reported in China. Interestingly, eight Thai PEDV strains possessed amino acid deletions in the N protein. The PEDV sequence divergence may be responsible for driving periodic outbreaks and continued persistence of PEDV on commercial swine farms. Our findings provide important insight into regional PEDV strains in circulation, which may assist future inclusions of suitable strains for future PEDV vaccines.

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Reactivity of Porcine Epidemic Diarrhea Virus Structural Proteins to Antibodies against Porcine Enteric Coronaviruses: Diagnostic Implications

Journal of Clinical Microbiology ◽

10.1128/jcm.02507-16 ◽

2017 ◽

Vol 55 (5) ◽

pp. 1426-1436 ◽

Cited By ~ 26

Author(s):

Luis Gabriel Gimenez-Lirola ◽

Jianqiang Zhang ◽

Jose Antonio Carrillo-Avila ◽

Qi Chen ◽

Ronaldo Magtoto ◽

...

Keyword(s):

Antibody Response ◽

Porcine Epidemic Diarrhea Virus ◽

Herd Immunity ◽

Cross Reactivity ◽

Structural Proteins ◽

Transmissible Gastroenteritis Virus ◽

Serum Samples ◽

Igg Antibody ◽

Diarrhea Virus ◽

Porcine Epidemic Diarrhea

ABSTRACTThe development of porcine epidemic diarrhea virus (PEDV) antibody-based assays is important for detecting infected animals, confirming previous virus exposure, and monitoring sow herd immunity. However, the potential cross-reactivity among porcine coronaviruses is a major concern for the development of pathogen-specific assays. In this study, we used serum samples (n= 792) from pigs of precisely known infection status and a multiplex fluorescent microbead-based immunoassay and/or enzyme-linked immunoassay platform to characterize the antibody response to PEDV whole-virus (WV) particles and recombinant polypeptides derived from the four PEDV structural proteins, i.e., spike (S), nucleocapsid (N), membrane (M), and envelope (E). Antibody assay cutoff values were selected to provide 100% diagnostic specificity for each target. The earliest IgG antibody response, mainly directed against S1 polypeptides, was observed at days 7 to 10 postinfection. With the exception of nonreactive protein E, we observed similar antibody ontogenies and patterns of seroconversion for S1, N, M, and WV antigens. Recombinant S1 provided the best diagnostic sensitivity, regardless of the PEDV strain, with no cross-reactivity detected against transmissible gastroenteritis virus (TGEV), porcine respiratory coronavirus (PRCV), or porcine deltacoronavirus (PDCoV) pig antisera. The WV particles showed some cross-reactivity to TGEV Miller and TGEV Purdue antisera, while N protein presented some cross-reactivity to TGEV Miller. The M protein was highly cross-reactive to TGEV and PRCV antisera. Differences in the antibody responses to specific PEDV structural proteins have important implications in the development and performance of antibody assays for the diagnosis of PEDV enteric disease.

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Structure and immune recognition of the porcine epidemic diarrhea virus spike protein

10.1101/2020.02.18.955195 ◽

2020 ◽

Cited By ~ 2

Author(s):

Robert N. Kirchdoerfer ◽

Mahesh Bhandari ◽

Olnita Martini ◽

Leigh M. Sewall ◽

Sandhya Bangaru ◽

...

Keyword(s):

Antibody Response ◽

Polyclonal Antibody ◽

Porcine Epidemic Diarrhea Virus ◽

Palmitoleic Acid ◽

Spike Protein ◽

Immune Recognition ◽

Diarrhea Virus ◽

Protein Interfaces ◽

Porcine Epidemic Diarrhea ◽

Protein Components

AbstractPorcine epidemic diarrhea virus is an alphacoronavirus responsible for significant morbidity and mortality in pigs. A key determinant of viral tropism and entry, the PEDV spike protein is a key target for the host antibody response and a good candidate for a protein-based vaccine immunogen. We used electron microscopy to evaluate the PEDV spike structure, as well as pig polyclonal antibody responses to viral infection. The structure of the PEDV spike reveals a configuration similar to that of HuCoV-NL63. Several PEDV protein-protein interfaces are mediated by non-protein components including a glycan at Asn264 and two bound palmitoleic acid molecules. The polyclonal antibody response to PEDV infection shows a dominance of epitopes in the S1 region. This structural and immune characterization provides new insights into coronavirus spike stability determinants and explores the immune landscape of viral spike proteins.

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