Co-infection status of porcine circoviruses (PCV2 and PCV3) and porcine epidemic diarrhea virus (PEDV) in pigs with watery diarrhea in Henan province, central China

Abstract Background Porcine epidemic diarrhea virus (PEDV), which is characterized by severe watery diarrhea, vomiting, dehydration and a high mortality rate in piglets, leads to enormous economic losses to the pork industry and remains a large challenge worldwide. Thus, a rapid and reliable method is required for epidemiological investigations and to evaluate the effect of immunization. However, the current diagnostic methods for PEDV are time-consuming and very expensive and rarely meet the requirements for clinical application. Nanobodies have been used in the clinic to overcome these problems because of the advantages of their easy expression and high level of stability. In the present work, a novel biotinylated nanobody-based blocking ELISA (bELISA) was developed to detect anti-PEDV antibodies in clinical pig serum. Results Using phage display technology and periplasmic extraction ELISA (PE-ELISA), anti-PEDV N protein nanobodies from three strains of PEDV were successfully isolated after three consecutive rounds of bio-panning from a high quality phage display VHH library. Then, purified Nb2-Avi-tag fusion protein was biotinylated in vitro. A novel bELISA was subsequently developed for the first time with biotinylated Nb2. The cutoff value for bELISA was 29.27%. One hundred and fifty clinical serum samples were tested by both newly developed bELISA and commercial kits. The sensitivity and specificity of bELISA were 100% and 93.18%, respectively, and the coincidence rate between the two methods was 94%. Conclusions In brief, bELISA is a rapid, low-cost, reliable and useful nanobody-based tool for the serological evaluation of current PEDV vaccines efficacy and indirect diagnosis of PEDV infection.

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Development of indirect enzyme-linked immunosorbent assay for detection of porcine epidemic diarrhea virus specific antibodies (IgG) in serum of naturally infected pigs

BMC Veterinary Research ◽

10.1186/s12917-019-2123-2 ◽

2019 ◽

Vol 15 (1) ◽

Cited By ~ 1

Author(s):

Ohnmar Myint ◽

Ayako Yoshida ◽

Satoshi Sekiguchi ◽

Nguyen Van Diep ◽

Naoyuki Fuke ◽

...

Keyword(s):

Sensitivity And Specificity ◽

High Mortality ◽

Porcine Epidemic Diarrhea Virus ◽

Indirect Elisa ◽

Neutralization Test ◽

Elisa Test ◽

Watery Diarrhea ◽

Economic Losses ◽

Diarrhea Virus ◽

Porcine Epidemic Diarrhea

Abstract Background Porcine epidemic diarrhea virus (PEDV) infection is a highly contagious infectious disease causing watery diarrhea, vomiting, dehydration and high mortality rate in newborn piglets. PEDV infection can cause high economic losses in pig industry. In Japan, a PEDV outbreak occurred with high mortality from 2013 to 2015. Even though until now, PEDV infection occurs sporadically. For the control and monitoring of PEDV infection, not only symptomatic pigs, but also asymptomatic pigs should be identified. The objective of this study is to develop and optimize novel indirect ELISA as a simple, rapid, sensitive and specific method for the detection of anti-PEDV antibodies and evaluate the efficacy of the assay as a diagnostic method for PED. Results One hundred sixty-two serum samples, consisting of 81 neutralization test (NT) positive and 81 NT negative sera, were applied to the assay. Indirect ELISA test based on whole virus antigen (NK94P6 strain) derived from Vero cell culture was evaluated by receiver operating characteristic (ROC) analysis with neutralization test (NT) as a reference method, and cut-off value was determined as 0.320 with sensitivity and specificity of 92.6 and 90.1%, respectively. The area under curve (AUC) was 0.949, indicating excellent accuracy of indirect ELISA test. There was significant positive correlation between indirect ELISA and neutralization test (R = 0.815, P < 0.05). Furthermore, the kappa statics showed the excellent agreement between these two tests (kappa value = 0.815). In addition, the sensitivity and specificity of preserved plates with different periods (1 day, 2 weeks, 1, 2, 3, 4, 5 and 6 months) after drying antigen coated plates were 100% and 80–100%, respectively. Conclusions The developed indirect ELISA test in our study would be useful as a reliable test for serological survey and disease control of PEDV infection, and our pre-antigen coated ELISA plates can be preserved at 4 °C until at least 6 months.

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Full-Length Genome Sequence of Porcine Epidemic Diarrhea Virus Strain CH/GX/2015/750A

Genome Announcements ◽

10.1128/genomea.00361-17 ◽

2017 ◽

Vol 5 (27) ◽

Cited By ~ 1

Author(s):

Yibin Qin ◽

Bingxia Lu ◽

Ying He ◽

Bin Li ◽

Qunpeng Duan ◽

...

Keyword(s):

Genome Sequence ◽

Virus Strain ◽

Complete Genome Sequence ◽

Porcine Epidemic Diarrhea Virus ◽

Complete Genome ◽

Full Length ◽

Watery Diarrhea ◽

Diarrhea Virus ◽

Porcine Epidemic Diarrhea ◽

Full Length Genome

ABSTRACT We report here the complete genome sequence of porcine epidemic diarrhea virus (PEDV) strain CH/GX/2015/750A (750A), which was isolated from a suckling piglet with watery diarrhea in Guangxi, China. The isolate is genetically close to other recent Chinese variant PEDVs and distinct from the classical PEDVs.

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Isolation and Identification of a Recombinant Porcine Epidemic Diarrhea Virus With a Novel Insertion in S1 Domain

Frontiers in Microbiology ◽

10.3389/fmicb.2021.667084 ◽

2021 ◽

Vol 12 ◽

Author(s):

Dongliang Li ◽

Yongtao Li ◽

Yunchao Liu ◽

Yumei Chen ◽

Wenqiang Jiao ◽

...

Keyword(s):

Porcine Epidemic Diarrhea Virus ◽

Driving Forces ◽

Viral Evolution ◽

Animal Experiments ◽

Central China ◽

N Gene ◽

Clinical Samples ◽

Isolation And Identification ◽

Diarrhea Virus ◽

Porcine Epidemic Diarrhea

Porcine epidemic diarrhea virus (PEDV) is the major pathogen that causes diarrhea and high mortality in newborn piglets with devastating impact to the pig industry. Recombination and mutation are the main driving forces of viral evolution and genetic diversity of PEDV. In 2016, an outbreak of diarrhea in piglets occurred in an intensive pig farm in Central China. A novel PEDV isolate (called HNAY) was successfully isolated from clinical samples. Sequence analysis and alignment showed that HNAY possessed 21-nucleotide (nt) insertion in its S1 gene, which has never been reported in other PEDV isolates. Moreover, the sequence of the insertion was identical with the sequence fragment in PEDV N gene. Notably, the HNAY strain exhibited two unique mutations (T500A and L521Y) in the neutralizing epitopes of the S1 protein that were different from those of other PEDV variant strains and CV777-based vaccine strains. Additionally, PEDV HNAY might be derived from a natural recombination between two Chinese variant PEDV strains. Animal experiments demonstrated that HNAY displayed higher pathogenicity compared with two other clinical isolates. This study lays the foundation for better understanding of the genetic evolution and molecular pathogenesis of PEDV.

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A Comprehensive View on the Host Factors and Viral Proteins Associated With Porcine Epidemic Diarrhea Virus Infection

Frontiers in Microbiology ◽

10.3389/fmicb.2021.762358 ◽

2021 ◽

Vol 12 ◽

Author(s):

Yi Hu ◽

Xiaohong Xie ◽

Lingchen Yang ◽

Aibing Wang

Keyword(s):

Virus Infection ◽

Porcine Epidemic Diarrhea Virus ◽

Molecular Mechanisms ◽

Viral Proteins ◽

Host Factors ◽

Watery Diarrhea ◽

Economic Losses ◽

Target Cells ◽

Diarrhea Virus ◽

Porcine Epidemic Diarrhea

Porcine epidemic diarrhea virus (PEDV), a coronavirus pathogen of the pig intestinal tract, can cause fatal watery diarrhea in piglets, thereby causing huge economic losses to swine industries around the world. The pathogenesis of PEDV has intensively been studied; however, the viral proteins of PEDV and the host factors in target cells, as well as their interactions, which are the foundation of the molecular mechanisms of viral infection, remain to be summarized and updated. PEDV has multiple important structural and functional proteins, which play various roles in the process of virus infection. Among them, the S and N proteins play vital roles in biological processes related to PEDV survival via interacting with the host cell proteins. Meanwhile, a number of host factors including receptors are required for the infection of PEDV via interacting with the viral proteins, thereby affecting the reproduction of PEDV and contributing to its life cycle. In this review, we provide an updated understanding of viral proteins and host factors, as well as their interactions in terms of PEDV infection. Additionally, the effects of cellular factors, events, and signaling pathways on PEDV infection are also discussed. Thus, these comprehensive and profound insights should facilitate for the further investigations, control, and prevention of PEDV infection.

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The New Porcine Epidemic Diarrhea Virus Outbreak May Mean That Existing Commercial Vaccines Are Not Enough to Fully Protect Against the Epidemic Strains

Frontiers in Veterinary Science ◽

10.3389/fvets.2021.697839 ◽

2021 ◽

Vol 8 ◽

Author(s):

Qi Gao ◽

Zezhong Zheng ◽

Heng Wang ◽

Songqiang Yi ◽

Guihong Zhang ◽

...

Keyword(s):

Porcine Epidemic Diarrhea Virus ◽

Prevention And Control ◽

Clinical Symptoms ◽

Control Measures ◽

Watery Diarrhea ◽

Sequencing Analysis ◽

Diarrhea Virus ◽

Pig Farm ◽

Porcine Epidemic Diarrhea ◽

And Control

Background: On October 30, 2020, piglets and sows in the farrowing house of a pig farm in Jiangxi showed clinical symptoms such as anorexia, watery diarrhea, and vomiting. Epidemiological test, clinical necropsy, and RT-PCR test were carried out on the pig farm for diagnosis. After comprehensive considerations, the disease was judged as porcine epidemic diarrhea virus infection.Results: Thereafter, a series of comprehensive prevention and control measures such as emergency vaccination with autogenous vaccines were adopted. Half a month after inoculation with autogenous vaccines for the farm, the mortality rate of newborn piglets in the farrowing house began to decline, and production gradually returned to being stable. The second-generation sequencing analysis and phylogenetic analysis showed that the porcine epidemic diarrhea virus (PEDV) sequence obtained from the stool and small intestine samples of the diseased pigs on the farm was 97.8% homologous to the vaccine strain. At the same time, antibody testing found that the vaccinated pigs on the pig farm had satisfactory immune response.Conclusion: This case indicated that the PEDV outbreak on the pig farm might aggravate owing to the strain being mutated and could escape the immune protection of the existing vaccine. This case has accumulated technical data for the clinical prevention and control of porcine epidemic diarrhea.

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Genetic variation analysis of reemerging porcine epidemic diarrhea virus prevailing in central China from 2010 to 2011

Virus Genes ◽

10.1007/s11262-012-0867-x ◽

2012 ◽

Vol 46 (2) ◽

pp. 337-344 ◽

Cited By ~ 24

Author(s):

Xia Yang ◽

Jin-yao Huo ◽

Lu Chen ◽

Feng-mei Zheng ◽

Hong-tao Chang ◽

...

Keyword(s):

Genetic Variation ◽

Porcine Epidemic Diarrhea Virus ◽

Central China ◽

Variation Analysis ◽

Diarrhea Virus ◽

Porcine Epidemic Diarrhea

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Manipulation of Intestinal Antiviral Innate Immunity and Immune Evasion Strategies of Porcine Epidemic Diarrhea Virus

BioMed Research International ◽

10.1155/2019/1862531 ◽

2019 ◽

Vol 2019 ◽

pp. 1-9 ◽

Cited By ~ 1

Author(s):

Jian Du ◽

Junqiu Luo ◽

Jie Yu ◽

Xiangbing Mao ◽

Yuheng Luo ◽

...

Keyword(s):

Innate Immunity ◽

Immune Evasion ◽

Porcine Epidemic Diarrhea Virus ◽

Current Knowledge ◽

Mucosal Barrier ◽

Watery Diarrhea ◽

Diarrhea Virus ◽

Successful Infection ◽

Porcine Epidemic Diarrhea ◽

Antiviral Innate Immunity

Porcine epidemic diarrhea virus (PEDV) infection causes watery diarrhea, dehydration, and high mortality in neonatal pigs, due to its clinical pathogenesis of the intestinal mucosal barrier dysfunction. The host’s innate immune system is the first line of defence upon virus invasion of the small intestinal epithelial cells. In turn, the virus has evolved to modulate the host’s innate immunity during infection, resulting in pathogen virulence, survival, and the establishment of successful infection. In this review, we gather current knowledge concerning the interplay between PEDV and components of host innate immunity, focusing on the role of cytokines and interferons in intestinal antiviral innate immunity, and the mechanisms underlying the immune evasion strategies of PEDV invasion. Finally, we provide some perspectives on the potential prevention and treatment for PEDV infection.

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Porcine Epidemic Diarrhea Virus and the Host Innate Immune Response

Pathogens ◽

10.3390/pathogens9050367 ◽

2020 ◽

Vol 9 (5) ◽

pp. 367 ◽

Cited By ~ 1

Author(s):

Shasha Li ◽

Jinping Yang ◽

Zixiang Zhu ◽

Haixue Zheng

Keyword(s):

Immune Response ◽

Innate Immune Response ◽

Porcine Epidemic Diarrhea Virus ◽

Innate Immune ◽

Viral Rna ◽

Watery Diarrhea ◽

Economic Losses ◽

Diarrhea Virus ◽

Host Innate Immune Response ◽

Porcine Epidemic Diarrhea

Porcine epidemic diarrhea virus (PEDV), a swine enteropathogenic coronavirus (CoV), is the causative agent of porcine epidemic diarrhea (PED). PED causes lethal watery diarrhea in piglets, which has led to substantial economic losses in many countries and is a great threat to the global swine industry. Interferons (IFNs) are major cytokines involved in host innate immune defense, which induce the expression of a broad range of antiviral effectors that help host to control and antagonize viral infections. PEDV infection does not elicit a robust IFN response, and some of the mechanisms used by the virus to counteract the host innate immune response have been unraveled. PEDV evades the host innate immune response by two main strategies including: 1) encoding IFN antagonists to disrupt innate immune pathway, and 2) hiding its viral RNA to avoid the exposure of viral RNA to immune sensors. This review highlights the immune evasion mechanisms employed by PEDV, which provides insights for the better understanding of PEDV-host interactions and developing effective vaccines and antivirals against CoVs.

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Porcine Epidemic Diarrhea Virus 3C-Like Protease Regulates Its Interferon Antagonism by Cleaving NEMO

Journal of Virology ◽

10.1128/jvi.02514-15 ◽

2015 ◽

Vol 90 (4) ◽

pp. 2090-2101 ◽

Cited By ~ 63

Author(s):

Dang Wang ◽

Liurong Fang ◽

Yanling Shi ◽

Huan Zhang ◽

Li Gao ◽

...

Keyword(s):

Immune Responses ◽

Cysteine Protease ◽

Porcine Epidemic Diarrhea Virus ◽

Protease Activity ◽

The United States ◽

Watery Diarrhea ◽

Type I ◽

Diarrhea Virus ◽

Cysteine Protease Activity ◽

Porcine Epidemic Diarrhea

ABSTRACTPorcine epidemic diarrhea virus (PEDV) is an enteropathogenic coronavirus causing lethal watery diarrhea in piglets. Since 2010, a PEDV variant has spread rapidly in China, and it emerged in the United States in 2013, posing significant economic and public health concerns. The ability to circumvent the interferon (IFN) antiviral response, as suggested for PEDV, promotes viral survival and regulates pathogenesis of PEDV infections, but the underlying mechanisms remain obscure. Here, we show that PEDV-encoded 3C-like protease, nsp5, is an IFN antagonist that proteolytically cleaves the nuclear transcription factor kappa B (NF-κB) essential modulator (NEMO), an essential adaptor bridging interferon-regulatory factor and NF-κB activation. NEMO is cleaved at glutamine 231 (Q231) by PEDV, and this cleavage impaired the ability of NEMO to activate downstream IFN production and to act as a signaling adaptor of the RIG-I/MDA5 pathway. Mutations specifically disrupting the cysteine protease activity of PEDV nsp5 abrogated NEMO cleavage and the inhibition of IFN induction. Structural analysis suggests that several key residues outside the catalytic sites of PEDV nsp5 probably impact NEMO cleavage by modulating potential interactions of nsp5 with their substrates. These data show that PEDV nsp5 disrupts type I IFN signaling by cleaving NEMO. Previously, we and others demonstrated that NEMO is also cleaved by 3C or 3C-like proteinases of picornavirus and artertivirus. Thus, NEMO probably represents a prime target for 3C or 3C-like proteinases of different viruses.IMPORTANCEThe continued emergence and reemergence of porcine epidemic diarrhea virus (PEDV) underscore the importance of studying how this virus manipulates the immune responses of its hosts. During coevolution with its hosts, PEDV has acquired mechanisms to subvert host innate immune responses for its survival advantage. At least two proteins encoded by PEDV have been identified as interferon (IFN) antagonists, papain-like protease (PLP) and N protein. Here, we report that the PEDV nsp5 gene, which encodes the 3C-like protease of PEDV, is another IFN antagonist. Mechanistically, the cysteine protease activity of PEDV nsp5 mediates proteolysis of NEMO, the key adaptor for IFN synthesis, and NEMO is cleaved at glutamine 231 (Q231). The new molecular details and determinants impacting NEMO scission by PEDV nsp5 delineated in this study are fundamental to our understanding of critical virus-host interactions that determine PEDV pathogenesis.

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