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

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

2016 ◽  
Vol 91 (2) ◽  
Author(s):  
Peera Jaru-Ampornpan ◽  
Juggragarn Jengarn ◽  
Asawin Wanitchang ◽  
Anan Jongkaewwattana

ABSTRACT Porcine epidemic diarrhea virus (PEDV) causes severe diarrhea and high mortality rates in newborn piglets, leading to massive losses to the swine industry worldwide during recent epidemics. Intense research efforts are now focusing on defining viral characteristics that confer a growth advantage, pathogenicity, or cell adaptability in order to better understand the PEDV life cycle and identify suitable targets for antiviral or vaccine development. Here, we report a unique phenomenon of PEDV nucleocapsid (N) cleavage by the PEDV-encoded 3C-like protease (3Cpro) during infection. The identification of the 3Cpro cleavage site at the C terminus of N supported previous observations that PEDV 3Cpro showed a substrate requirement slightly different from that of severe acute respiratory syndrome coronavirus (SARS-CoV) 3Cpro and revealed a greater flexibility in its substrate recognition site. This cleavage motif is present in the majority of cell culture-adapted PEDV strains but is missing in emerging field isolates. Remarkably, reverse-genetics-derived cell culture-adapted PEDVAVCT12 harboring uncleavable N displayed growth retardation in Vero E6-APN cells compared to the wild-type virus. These observations altogether shed new light on the investigation and characterization of the PEDV nucleocapsid protein and its possible link to cell culture adaptation. IMPORTANCE Recurrent PEDV outbreaks have resulted in enormous economic losses to swine industries worldwide. To gain the upper hand in combating this disease, it is necessary to understand how this virus replicates and evades host immunity. Characterization of viral proteins provides important clues to mechanisms by which viruses survive and spread. Here, we characterized an intriguing phenomenon in which the nucleocapsids of some PEDV strains are proteolytically processed by the virally encoded main protease. Growth retardation in recombinant PEDV carrying uncleavable N suggests a replication advantage provided by the cleavage event, at least in the cell culture system. These findings may direct us to a more complete understanding of PEDV replication and pathogenicity.


2020 ◽  
Author(s):  
Zhige Tian ◽  
Yuexiao Lian ◽  
Xiaoliang Hu ◽  
Yue Shi ◽  
Feng Cong

Abstract Background: Since 2010, variant porcine epidemic diarrhea virus (PEDV) has emerged in several provinces of China. The variant strain causes high mortality of newborn piglets, which has resulted in severe economic losses to the pork breeding industry.Results: A variant PEDV strain, SC-YB73, was isolated and identified in China. Pathological observation showed atrophy of villi and edema in the lamina propria. Sequence analysis indicated that six nucleotides were inserted in the E gene, which was first detected in PEDV strains. Furthermore, fifty nucleotide sites were unique in SC-YB73, when compared with another 28 PEDV strains. Phylogenetic analysis based on the complete genome showed that SC-YB73 was clustered in the variant subgroup GII-a, which is widely prevalent in the pig population in China. Recombination analysis suggested that SC-YB73 originated from the recombination of GDS47, TW/Yunlin550/2018, and COL/Cundinamarca/2014.Conclusion: The present study involved the isolation and genetic characterization of a variant PEDV strain. It will provide essential information for the control of PED outbreaks in China.


2015 ◽  
Vol 160 (4) ◽  
pp. 1055-1064 ◽  
Author(s):  
Seong-Hee Kim ◽  
Jung-Min Lee ◽  
Jongsun Jung ◽  
In-Joong Kim ◽  
Bang-Hun Hyun ◽  
...  

Virology ◽  
2017 ◽  
Vol 500 ◽  
pp. 50-61 ◽  
Author(s):  
Baochao Fan ◽  
Zhengyu Yu ◽  
Fengjiao Pang ◽  
Xiangwei Xu ◽  
Baimeng Zhang ◽  
...  

1998 ◽  
Vol 5 (3) ◽  
pp. 412-414 ◽  
Author(s):  
Franco Guscetti ◽  
Curzio Bernasconi ◽  
Kurt Tobler ◽  
Kristien Van Reeth ◽  
Andreas Pospischil ◽  
...  

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.


2019 ◽  
Vol 17 (1) ◽  
Author(s):  
Zhiqian Ma ◽  
Tianyu Wang ◽  
Zhiwei Li ◽  
Xuyang Guo ◽  
Yangsheng Tian ◽  
...  

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.


Virus Genes ◽  
2017 ◽  
Vol 54 (2) ◽  
pp. 215-224 ◽  
Author(s):  
Rocío Lara-Romero ◽  
Luis Gómez-Núñez ◽  
José Luis Cerriteño-Sánchez ◽  
Laura Márquez-Valdelamar ◽  
Susana Mendoza-Elvira ◽  
...  

2019 ◽  
Vol 16 (1) ◽  
Author(s):  
Yu Wu ◽  
Wei Li ◽  
Qingfeng Zhou ◽  
Qunhui Li ◽  
Zhichao Xu ◽  
...  

Abstract Background Porcine epidemic diarrhea virus (PEDV) has caused enormous economic losses to the global pig industry. Currently available PEDV vaccine strains have limited protective effects against PEDV variant strains. Methods In this study, the highly virulent epidemic virus strain CT was serially passaged in Vero cells for up to 120 generations (P120). Characterization of the different passages revealed that compared with P10 and P64, P120 had a higher viral titer and more obvious cytopathic effects, thereby demonstrating better cell adaptability. Results Pathogenicity experiments using P120 in piglets revealed significant reductions in clinical symptoms, histopathological lesions, and intestinal PEDV antigen distribution; the piglet survival rate in the P120 group was 100%. Furthermore, whole-genome sequencing identified 13 amino acid changes in P120, which might be responsible for the attenuated virulence of P120. Conclusions Thus, an attenuated strain was obtained via cell passaging and that this strain could be used in preparing attenuated vaccines.


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