scholarly journals Immunohistochemical Detection of Porcine Epidemic Diarrhea Virus Compared to Other Methods

1998 ◽  
Vol 5 (3) ◽  
pp. 412-414 ◽  
Author(s):  
Franco Guscetti ◽  
Curzio Bernasconi ◽  
Kurt Tobler ◽  
Kristien Van Reeth ◽  
Andreas Pospischil ◽  
...  
Keyword(s):  
Porcine Epidemic Diarrhea Virus ◽  
Clinical Samples ◽  
Enzyme Linked Immunosorbent Assay ◽  
Direct Immunofluorescence ◽  
Good Reliability ◽  
Diarrhea Virus ◽  
Pcr Method ◽  
Porcine Epidemic Diarrhea ◽  
Cryostat Sections ◽  
Formalin Fixed

ABSTRACT An immunohistochemistry method using formalin-fixed tissues, a direct immunofluorescence method using cryostat sections, an enzyme-linked immunosorbent assay (ELISA), and a PCR method were compared for diagnosis in a litter of weaned pigs that had been experimentally inoculated with wild-type porcine epidemic diarrhea virus (PEDV) and killed between 6 and 60 h after onset of diarrhea. The immunohistochemistry method proved to be as reliable as direct immunofluorescence for diagnosis of PEDV in tissues collected postmortem. The good reliability of ELISA for investigating clinical samples was confirmed, whereas the PCR method used was ineffective.

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

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.

scholarly journals The N-terminal domain of Spike protein contributes to antigenicity difference between porcine epidemic diarrhea virus genotypes G1 and G2

2021 ◽  
Author(s):  
Qi-long Qiao ◽  
Ning Li ◽  
Ming-zhen Song ◽  
Jing Chen ◽  
Pan pan Yang ◽  
...  
Keyword(s):  
Amino Acid ◽  
Porcine Epidemic Diarrhea Virus ◽  
Enzyme Linked Immunosorbent Assay ◽  
S Protein ◽  
Diarrhea Virus ◽  
Terminal Domain ◽  
Porcine Epidemic Diarrhea ◽  
Amino Acid Mutations ◽  
Multiple Amino Acid ◽  
S Proteins

Porcine epidemic diarrhea virus (PEDV) strains have been clarified into two genotypes, G1 and G2, based on the sequence of the spike (S) gene. Amino acid mutations that distinguish the two PEDV genotypes were mostly located in the N-terminal domain (NTD) (aa 1-380) of S protein. The fact of increased outbreaks of G2 subtype PEDV and the failure of G1 subtype PEDV strain (CV777)-based vaccine in China since 2010 suggested that multiple amino acid mutations located in the NTD altered the antigenicity of S protein. To determine the role of the NTD of S protein in the antigenicity difference, the NTD of the CV777 vaccine strain (G1) and CH/ZMDZY/11 strain (G2) was expressed in E. coli, respectively. polyclonal antibodies (PAbs) against genotype-specific S proteins were prepared by immunizing BALB/c mice using purified S proteins. Antigenicity was systematically compared by detection of PAbs against two genotype PEDV strains and purified S proteins using Western blot, indirect enzyme-linked immunosorbent assay (ELISA), indirect immunofluorescence assay (IFA), and serum cross-neutralization assay (SN). Consistent with the multiple amino acid mutations in the NTD of S protein, different antigenic cross-reactivity between the two genotypes was demonstrated. There was six-fold and more than twenty-fold difference in ELISA and SN titer between anti-CV777 S protein antibodies against G1 and G2 subtype strains, respectively. There was twofold and eight-fold difference in ELISA and SN titer between anti-ZMDZY S protein antibodies against G1 and G2 genotype strains, respectively. The results proved that the NTD of S protein contributes to the antigenicity difference between PEDV genotypes G1 and G2, and highlighted a G2 strain should be used to develop a vaccine for providing better protection against prevalent genotype of PEDV.

scholarly journals Genetic Characterization of Porcine Epidemic Diarrhea Virus in China Between 2014 and 2018: Emergence of the G1c Subtype

2020 ◽  
Vol 40 (04) ◽  
pp. 474-478
Author(s):  
Wenqiang Jiao
Keyword(s):  
Porcine Epidemic Diarrhea Virus ◽  
Phylogenetic Trees ◽  
Genetic Characterization ◽  
Diagnostic Methods ◽  
Clinical Samples ◽  
Swine Industry ◽  
Diarrhea Virus ◽  
Positive Rate ◽  
Porcine Epidemic Diarrhea

Porcine epidemic diarrhea virus (PEDV) has caused substantial economical loss to the Chinese swine industry. To illustrate the genetic characterization of PEDV circulating in China, 205 clinical samples between 2014 and 2018 were collected from 7 provinces in China. 93.17% (191 of 205) of the intestinal and fecal samples were positive for PEDV. 25 S1 amino acid (aa) together with 27 ORF3 genes from 8 provinces were sequenced and analyzed. The phylogenetic trees based on the S1 and ORF3 genes were constructed by the neighbor-joining method using MEGA 7 software. PEDV prevalence was 86.96% (40 of 46) of the swine farms in the 8 provinces and the PEDV positive rate was 93.17% (191 of 205) in the tested samples. Genetic analysis showed CH-JIANGXI-1-2016 CH-JIAGNXI-2-2016, CH-JIANGXI-3-2016 and CH-JIANGXI-2017 had three notable insertions or deletions occurred at aa 59-62, 160, and 139 (140) when compared to all of the strains in this study; moreover, phylogenetic analysis indicated that the four isolates formed a new branch significantly different from G1a, G1b and Indel subtype based on S1 gene: that is the G1c subtype. More research is needed to determine whether the insertions and deletions had biological influence on the virus. The results acquired in the present study showed the genetic diversity of PEDV circulating in 8 provinces, providing information for the development of new diagnostic methods and new vaccines

Development and application of an indirect enzyme-linked immunosorbent assay using recombinant S1 for serological testing of porcine epidemic diarrhea virus

2019 ◽  
Vol 65 (5) ◽  
pp. 343-352
Author(s):  
Ying Shan ◽  
Yajie Liu ◽  
Ziqi Liu ◽  
Guowei Li ◽  
Cong Chen ◽  
...  
Keyword(s):  
Immunosorbent Assay ◽  
Porcine Epidemic Diarrhea Virus ◽  
Fluorescent Antibody ◽  
Area Under The Curve ◽  
Antibody Detection ◽  
Economic Losses ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Diarrhea Virus ◽  
Porcine Epidemic Diarrhea

Porcine epidemic diarrhea virus (PEDV) causes severe infectious diseases in all ages of swine and leads to serious economic losses. Serologic tests are widely accepted and used to detect anti-PEDV antibodies that could indicate PEDV infection or vaccination. In this study, PEDV recombinant S1 protein (rS1) was expressed with the Bac-to-Bac system and purified by nickel-affinity chromatography. An indirect enzyme-linked immunosorbent assay based on rS1 (rS1-ELISA) was then developed and optimized by checkerboard assays with serial dilutions of antigen and serum. Serum samples from 453 domestic pigs and 42 vaccinated pigs were analyzed by the indirect fluorescent antibody (IFA) test and rS1-ELISA. Taking IFA as a gold standard, rS1-ELISA produced a high sensitivity (90.7%) and specificity (94.6%) by a receiver operating characteristic (ROC) curve. In addition, ROC analysis also revealed that rS1-ELISA was consistent with IFA (area under the curve 0.9583 ± 0.0082). This rS1-ELISA was then applied to antibody detection in inactivated PEDV vaccinated pigs. The antibody could be detected 2–4 weeks after the first inoculation. These results indicated that the rS1-ELISA established in this study provides a promising and reliable tool for serologic detection of anti-PEDV IgG antibodies in infected or vaccinated pigs.

scholarly journals Evaluation of the Efficacy of Lactogenic Immunity of Sow Induced by Porcine Epidemic Diarrhea Virus (PEDV) Vaccine By Intranasal Immunization

2021 ◽  
Author(s):  
Shengchao Deng ◽  
Juan Wang ◽  
Mudassar Mohiuddin ◽  
Lisai Zhu ◽  
Guiping Wang ◽  
...  
Keyword(s):  
Porcine Epidemic Diarrhea Virus ◽  
Protective Efficacy ◽  
Virulent Strain ◽  
Passive Immunization ◽  
Enzyme Linked Immunosorbent Assay ◽  
Diarrhea Virus ◽  
Suckling Piglets ◽  
Porcine Epidemic Diarrhea ◽  
Lactogenic Immunity ◽  
Highly Virulent

Abstract Background: Porcine epidemic diarrhea virus belongs to family of coronaviruses which are notorious for rapid spread of severe diarrhea among suckling piglets. The virus mainly replicates in the epithelial cells of duodenum, jejunum, ileum and colon and is a life threatening condition in pigs. A highly virulent strain “CHYJ130330” having high mortality rate was isolated from a field outbreak, identified as a new virulent genotype II/G2-b strain and adapted successfully to vero cells was used to prepare inactivated vaccine against PEDV. This newly prepared vaccine was given through intranasal route and is compared with the commercially available bi-combined (PEDV and TGEV) vaccine given by intramuscular injection. In this study milk or mucosal IgA and IgG antibody levels have been used to predict vaccine efficacy and the level of protective immunity against PED virus. Antibody titers in the milk of sows and intestines of suckling piglets were compared by enzyme-linked immunosorbent assay (ELISA). Results: It was shown that CHYJ vaccine induced significantly higher levels of PEDV IgA antibody in milk of sows and intestines of piglets as compared to commercial bi-combined vaccine. Both CHYJ and commercial vaccines were not able to induce detectable IgG levels in the intestines of piglets; the later however induced higher IgG levels when detected in the sow’s milk. Protective efficacy of vaccines was determined against a highly virulent PEDV strain. CHYJ intranasal vaccine gives a better protection 80% (4/5) rate as compared to commercial i.m. vaccine conferring 60% (3/5) immunity in suckling piglets. Conclusions: It is therefore concluded that PEDV inactivated CHYJ vaccine confer better lactogenic immunity and gives more protection to suckling piglets than available bi-combined TGEV and PEDV vaccine through passive immunization.

scholarly journals Genetic characterization and phylogenetic analysis of porcine epidemic diarrhea virus in Guangdong, China, between 2018 and 2019

PLoS ONE ◽  
2021 ◽  
Vol 16 (6) ◽  
pp. e0253622
Author(s):  
Feng Wen ◽  
Jing Yang ◽  
Anqi Li ◽  
Zhonggui Gong ◽  
Lulu Yang ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Porcine Epidemic Diarrhea Virus ◽  
Southern China ◽  
Guangdong Province ◽  
Clinical Samples ◽  
Transmissible Gastroenteritis Virus ◽  
Genetic Characteristics ◽  
Common Amino Acid ◽  
Diarrhea Virus ◽  
Porcine Epidemic Diarrhea

Porcine epidemic diarrhea virus (PEDV), a leading cause of piglet diarrhea outbreaks, poses a significant danger to the swine industry. The aim of this study was to investigate the epidemic characteristics of PEDV that was circulating in Guangdong province, one of China’s major pig producing provinces. Clinical samples were collected from eight pig farms in Guangdong province between 2018 and 2019 and tested for the major porcine enteric pathogens, including PEDV, transmissible gastroenteritis virus (TGEV), Swine enteric coronavirus (SeCoV), Swine acute diarrhea syndrome coronavirus (SADS-CoV), porcine deltacoronavirus (PDCoV), and porcine rotavirus (RV). As a result, only PEDV and RV were detected at a rate of 47.0% (16/34) and 18.6% (8/34), respectively. Coinfectoin with PEDV and RV occurred at a rate of PEDV 12.5% (2/16). Subsequently, the full-length S gene sequences of 13 PEDV strains were obtained, and phylogenetic analysis suggested the presence of GII-c group PEDV strains in this region (non-S-INDEL). Two novel common amino acid insertions (55T/IG56 and 551L) and one novel glycosylation site (1199G+) were detected when the CV777 and ZJ08 vaccine strains were compared. Furthermore, intragroup recombination events in the S gene regions 51–548 and 2478–4208 were observed in the PEDV strains studied. In summary, the observations provide current information on the incidence of viral agents causing swine diarrhea in southern China and detailed the genetic characteristics and evolutionary history of the dominant PEDV field strains. Our findings will aid in the development of an updated vaccine for the prevention and control of PEDV variant strains.

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