• Microbiology and Biotechnology Letters
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• v.39 no.2
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• pp.140-145
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• 2011

Porcine epidemic diarrhea virus (PEDV) infection causes acute enteritis with lethal watery diarrhea resulting in a high mortality rate in piglets. As with the other members of group 1 coronaviruses, PEDV also utilizes the host aminopeptidase N (APN) as the major cellular receptor for entry into target cells. The coronavirus spike (S) protein is known to interact with the cellular surface for viral attachment and the S1 domain of all characterized coronaviruses contains a receptor-binding domain (RBD) that mediates a specific high-affinity interaction with their respective cellular receptors. Although the RBDs of several coronaviruses have been mapped, the location of the PEDV RBD has to date not been defined. As a first step toward the identification of the region of the S protein of the PEDV that is critical for recognition with the cellular receptor, we generated a series of S1-truncated variants and examined their abilities to bind to the porcine APN (pAPN) receptor. Our data indicate that the N-terminus of the S1 domain is required for pAPN association. The results from the present study may assist in our understanding of the molecular interactions between the PEDV S protein and the pAPN receptor.

• Korean Journal of Veterinary Research
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• v.48 no.2
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• pp.167-174
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• 2008

Lactic acid bacteria have been reported their beneficial roles on host including reduction of infectious diarrhea problems. In this study, preventive effect of Lactobacillus (L.) reuteri HY25101 and L. johnsonii HY25103 on porcine epidemic diarrhea virus (PEDV) was investigated in suckling piglets. Two groups of one day old PEDV naïve piglets were orally administered L. reuteri HY25101 and L. johnsonii HY25103 for three days respectively before challenge with lethal dose of PEDV. In second experiment, passive immunized one day old piglets using colostrums containing PEDV specific IgA were used. The survival rates of the L. reuteri HY25101 administered group were significantly higher than that of L. johnsonii HY25103 administered group and viral shedding was rapidly diminished in L. reuteri HY25101 administered group. Interestingly piglets born from the sow immunized with attenuated PEDV vaccine were not completely protected from PEDV challenge, however coadministeration of L. reuteri HY25101 and colostrums containing PEDV specific IgA were more effectively prevent PEDV infection. These results suggested that dietary treatment using L. reuteri HY25101 could reduce diarrheal problem and mortality rate caused by PEDV in suckling pigs. In addition, L. reuteri HY25101 could be used as one of effective compensation treatment with attenuated live vaccine for PED.

• Korean Journal of Veterinary Research
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• v.34 no.2
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• pp.321-326
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• 1994

Korean isolate, porcine epidemic diarrhea virus (KPEDV-9) was adapted through serial passages in vero cell. The viral yield reached up to $10^{5-6}$ $TCID_{50}/ml$ at the passage level of 90th. The cell adapted virus was characterized through genetic and morphological examinations. The RNA extracted from virus infected cell revealed the presence of RNA band with molecular size of >20Kb. The electron microscopic examination on purified virus showed the pleomorphic appearance of enveloped particles with 5-10nm surface projections, which fit with the shape of coronavirus. The etiological survey on swine diarrhea by immunofluorescence test(FA) indicated 17.5% positive rate on the PEDV infection. In addition, the incidence were detected both in piglets within two weeks old as well as fattening pigs. Serological survey by ELISA revealed the overall 45% positive result, thus, indicating the PEDV infection are widespread throughout this country.

• Journal of Animal Science and Technology
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• v.57 no.10
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• pp.33.1-33.7
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• 2015

The objective of this study was to evaluate effects of a combined use of extracts of medicinal herbs Taraxaumi mongolicum, Viola yedoensis Makino, Rhizoma coptidis, and Radix isatidis (MYCI) on porcine epidemic diarrhea (PED). Twenty-two 3-day-old piglets received an oral challenge with $3{\times}10^{3.5}$ $TCID_{50}$ of the virulent PED virus (PEDV) in PBS or PBS only and daily oral administration of 60 mg of the MYCI mixture suspended in milk replacer or the vehicle for 7 days in a $2{\times}2$ factorial arrangement of treatments. Average daily gain (ADG) increased (p < 0.05) in response to the MYCI treatment in the PEDV-challenged piglets (-18 vs. 7 g for the vehicle- vs. MYCI-administered group), but not in unchallenged animals (27 vs. 28 g). Diarrhea score and fecal PEDV shedding, however, were not influenced by the MYCI treatment. The PEDV challenge caused severe intestinal villus atrophy and crypt hyperplasia, both of which were alleviated by administration of the MYCI mixture as indicated by an increase in the villus height and a decrease in the crypt depth due to the treatment. Overall, medicinal herb extracts used in this study ameliorated impaired growth performance and intestinal lesion of newborn piglets challenged with the virulent PEDV. Therefore, our results suggest that the MYCI mixture could be used as a prophylactic or therapeutic agent against PED.

• Korean Journal of Veterinary Service
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• v.32 no.1
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• pp.11-18
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• 2009

Porcine epidemic diarrhea virus (PEDV), an enveloped single stranded RNA virus in the family Coronaviridae, causes acute viral enteric disease in piglets. Recently outbreaks of porcine epidemic diarrhea (PED) have been rare in Europe but frequent in Asia. In Korea, the increase of PED prevalence is showing specially in postweaning pigs. The purpose of this study was to investigate nucleotide sequence of nucleocapsid protein gene of PEDV field isolates from postweaning pigs in Korea and get more information about the viruses. A total of 15 postweaing pigs clinically suspected of PEDV infection by severe watery diarrhea and dehydration were used in this study. Viral RNA was extracted from small intestines and stools of the pigs. The N gene was amplified by nested RT-PCR, purificated, sequenced, analyzed and then compared with published sequences of other PEDV strains. Three PEDVs were isolated from the suspected postweaning pigs. The N gene of three PEDV field isolates consisted of 483 nucleotides. These PEDV field isolates showed nucleotide sequence homology range from 99.6% to 95% with Chinese strains, from 99.8% to 95.2% with Korean strains, from 97.3% to 95.7% with Japanese strains and from 96.5% to 95.7% with Belgium and British strains. The encoded pritein shared range from 98.8% to 95.6% with Chinese strains, from 99.4% to 95% with Korean strains, from 97.5% to 96.3% with Japanese strains, from 95.6% to 95% with Belgium and British strains. By phylogenetic tree analysis based on nucleotide sequence, three PEDV field isolates were clustered into two groups which were Chinese isolate groups and other Korean isolate groups. These results indicated that some of PEDV field isolates prevailing in Korean postweaning pigs may be associated with those of Chinese strains and other Korean strains.

• Proceedings of the Korean Society of Veterinary Pathology Conference
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• 2003.10a
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• pp.27-27
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• 2003

Porcine epidemic diarrhea virus (PEDV) and transmissible gastroenteritis virus (TGEV) infections are considered difficult to distinguish clinically and histopathologically. Prompt differentiation between PEDV- and TGEV-associated enteritis would greatly facilitate the management of disease in countries where PEDV and TGEV are epizootic. Rapid differential diagnosis and treatment are crucial to reducing mortality and morbidity from PEDV- and TGEV-induced enteritis in piglets. The objective for this study was to develop a protocol to differentiate between PEDV and TGEV directly from formalin-fixed, paraffin-embedded tissue, using a multiplex reverse transcription-nested polymerase chain reaction (RT-nPCR) assay. (omitted)

• Korean Chemical Engineering Research
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• v.49 no.5
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• pp.588-593
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• 2011

The porcine epidemic diarrhea virus(PEDV) production yield in spinner flask cultures using Vero cells immobilized on microcarriers was improved by the selective adsorption of ammonium ions in a Carberry type bioreactor which was equipped with Phillipsite-Gismondine synthetic zeolite. Though the apparent cell growth seemed to be lower than that of control due to the aggregation of microcarriers between impeller shaft and the adsorbent, zeolite was found to not to be toxic to Vero cell, considering estimated glucose and lactate changes. Zeolite was observed to remove ammonium ions effectively in both steps of cell growth and virus production. In virus production, the virus titer with zeolite was two times higher than that without zeolite. Consequently, zeolite was found to be an ideal adsorbent for higher production of virus vaccine with the effective removal of ammonium ions.

• Journal of Life Science
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• v.19 no.9
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• pp.1304-1308
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• 2009

To investigate the infection patterns of porcine epidemic diarrhea virus (PEDV) in Korean pig farms, a total of 4,768 swine sera samples from 159 pig farms were taken twice, in June (n=82) and October (n=77) in 2007. In each farm selected for the survey, 10 samples from breeding pigs and 4 from each of the 5 age groups (30, 60, 90, 120, and 150 days) were taken, and all serum samples were tested for PEDV by the serum neutralization test. The overall seroprevalence was 62.6% (2,983/4,768), with the highest prevalence in breeding pigs (93.5%, 1,485/1,589). The prevalence showed an increasing trend with increasing age (30.8, 27.2, 44.7, 61.6, and 71.2% respectively in the 30, 60, 90, 120, and 150 days age groups) (p<0.0001 for $x^2$ trend test). The association between age and PEDV prevalence was similar in both surveys, indicating that the infection of PEDV seemed to be occurring repeatedly in the farms surveyed. This inference could also be explained by the fact that prevalence in sows was very high despite low vaccination coverage, as they are continuously exposed to PEDV in potentially infected farms for a longer period. Based on the neutralizing antibody levels in sows and growing pigs, the majority of farms (91.8%, n=146 farms) were endemically infected with PEDV, and most of pigs seemed to be intensively infected with PEDV at around early growth (41.8%) and weaning (31.5%). On the other hand, serum neutralizing antibodies were not detected in pigs older than 30 days of age in farms classified as having no PEDV infection (n=13 farms), indicating the level of maternal antibody against PEDV is decreased on a non-detectable level before the piglet is 60 days old in the field situation. The results indicated that most farms surveyed in 2007 were affected with endemic PEDV infection. Therefore, a national monitoring and control program for the endemic type PEDV infection needs further attention.

• Korean Journal of Veterinary Research
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• v.61 no.4
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• pp.30.1-30.11
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• 2021

From April 2014 to September 2015, 153 piglets from 52 farms in Jeju were diagnosed with porcine epidemic diarrhea (PED). The major PED cases were focused on suckling piglets (144 piglets, 94.1%), particularly in 1-7-day-old piglets. Histopathologically, severe villous atrophy was observed in the small intestine, especially in the jejunum and ileum. The mean villous height to crypt depth ratios of the jejunum and ileum were 1.4:1 and 1.5:1, respectively. The major histopathologic findings of the small intestine were cytoplasmic vacuolation, cuboidalization, squamation, and exfoliation of the mucosal enterocytes in the villi. The cytoplasmic vacuolations in the enterocytes were the most prevalent lesions in the small intestine and were more severe in the ileum than in the jejunum. According to immunohistochemistry methods, the PED virus (PEDV) antigens were presented in the cytoplasms of the enterocytes, and were distributed more prevalently in the ileum than in the jejunum. PEDV antigens were also detected in the colon of 26 piglets (19.5%). Sequence comparison and phylogenetic analysis indicated that 12 PEDV had more than a 98.9% homology with each other. These PEDV strains were highly homologous with the genogroup 2 North American group.

• Journal of Veterinary Science
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• v.21 no.2
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• pp.25.1-25.16
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• 2020

Porcine epidemic diarrhea virus (PEDV) emerged into Canada in January 2014, primarily affecting sow herds. Subsequent epidemiological analyses suggested contaminated feed was the most likely transmission pathway. The primary objective of this study was to describe general biosecurity and management practices implemented in PEDV-positive sow herds and matched control herds at the time the virus emerged. The secondary objective was to determine if any of these general biosecurity and farm management practices were important in explaining PEDV infection status from January 22, 2014 to March 1, 2014. A case herd was defined as a swine herd with clinical signs and a positive test result for PEDV. A questionnaire was used to a gather 30-day history of herd management practices, animal movements on/off site, feed management practices, semen deliveries and biosecurity practices for case (n = 8) and control (n = 12) herds, primarily located in Ontario. Data was analyzed using descriptive statistics and random forests (RFs). Case herds were larger in size than control herds. Case herds had more animal movements and non-staff movements onto the site. Also, case herds had higher quantities of pigs delivered, feed deliveries and semen deliveries on-site. The biosecurity practices of case herds were considered more rigorous based on herd management, feed deliveries, transportation and truck driver practices than control herds. The RF model found that the most important variables for predicting herd status were related to herd size and feed management variables. Nonetheless, predictive accuracy of the final RF model was 72%.