• Korean Journal of Veterinary Pathology
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• v.6 no.1
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• pp.19-26
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• 2002

The purpose of this study was to investigate to potective effects against porcine epidemic diarrhea virus (PEDV) infection in piglets by administration of the PEDV antiserum orally at 2 hrs, 24hrs and 36hrs after birth. six piglets administered the antiserum were experimentally infected with PEDV at five-day-old. Control group were four piglets infected with PEDV only. Serum antibody titers against PEDV were examined by serum neutralization (SN) test, dectection for PEDV or PEDV antigen from feces and small intestines was tested by reverse transcription-polymerase chain reaction (RT-PCR) and indirect immunoflurescence (IFA). The results obtained were as follows; 1. The piglets administered the PEDV antiserum showed higher antibody titers than those of control group and sustained during the experimental period. 2. The detection rate of PEDV in feces and small intestines by RT-PCR were 26.2% and 16.7% in PEDV antiserum treated group and 48.1 % and 75.0% in control group, respectively. 3. The detection rate of PEDV antigen in the small intestine by IFA were 0% in PEDV antiserum treated group and 50.0% in control group, respectively. It was concluded that oral administration of antiserum against PEDV to piglets was effective in preventing PEDV infection.

• Korean Journal of Veterinary Service
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• v.32 no.3
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• pp.177-187
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• 2009

The purpose of this study was to evaluate the effect of a subsequent infection of PCV2 on piglets with PEDV. The results obtained were as follows: Antibodies against PCV2 and PEDV were detected at 24, 36, 48, 60 and 72h postinfection. And the antibody titers of alone infections with PEDV were gradually reduced and increased from 60 hpi to 72 hpi. Whereas, the antibody titers of dual infections with PCV2 and PEDV were gradually reduced all the time. PEDV antigens were detected at 24, 36, 48, 60 and 72 hpi, being seen almost exclusively in feces and small intestines from PEDV-infected piglets and PCV2-coinfected piglets. The detection rate of PEDV in feces and jejunum tissues by RT-PCR were 94.9% and 91.1% in dual infections and 87.1% and 83.6% in alone infections with PEDV, respectively. In dual infected piglets, significantly more PEDV antigens were detected in the feces and small intestines tissues at 24 hpi (P<0.05) than in the same feces and tissues of the alone infected piglets. Thereafter, at 72 hpi significantly more PEDV antigens (P<0.05) was detected in the jejunal tissues of the dual infected piglets with than of alone PEDV-infected piglets. The detection rate of PEDV antigen in the duodenum, jejunum and ileum by IFA were 91.3%, 91.3% and 83.3% in dual infected piglets and 75.0%, 83% and 75% in alone infected piglets, respectively. Intense and specific fluorescence signals were more often seen within jejunal villous enterocytes in dual infected piglets than alone infected piglets.

• 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 Pathology
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• v.6 no.1
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• pp.27-39
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• 2002

The purpose of this study was to investigate to protective effects against porcine epidemic diarrhea virus (PEDV) infection in piglets by administration of the PEDV antiserum orally at 2 hrs, 24hrs and 36hrs after birth. six piglets administered the antiserum were experimentally infected with PEDV at five-day-old. Control group were four piglets infected with PEDV only. Clinical signs and gross, histopathological lesion and immunohistochemical findings were examined. The results obtained were as follows; 1. In clinical signs, piglets of the control group appeared the typical signs of severe watery diarrhea, depression and anorexia but piglets of the PEDV antiserum treated group recovered progressively. In mortality, control group showed 75%, but PEDV antiserum treated group showed 16.7%, respectively. 2. In gross findings, piglets of the control group appeared the typical findings of congestion, distension of lumen, containing curdes of undigested milk in stomach. But piglets of the PEDV antiserum treated group appeared milder than those of control group. 3. In histopathological findings, piglets of the control group appeared the typical findings of villous atrophy and fusion, congesion, exfoliation, vacuolation, squamation, loss of cilia and proliferation of crypt. But piglets of the PEDV antiserum treated group appeared milder than those of control group. 4. In immunohistochemical findings, piglets of the PEDV antiserum treated group showed more intensive in reaction for IgG and IgG than those of control group. The recation for IgA was stronger than that of IgG. It was concluded that oral administration of PEDV antiserum to piglets was effective in preventing PEDV infection and reduced their mortality.

• Korean Journal of Veterinary Service
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• v.32 no.3
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• pp.201-207
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• 2009

Porcine transmissible gastroenteritis virus (TGEV), porcine epidemic diarrhea virus (PEDV) and rotaviruses are considered as the most important causative agents of diarrhea in piglets. The study established 3 method vaccination programs to prevent PEDV. A (LL)group inoculated twice vaccinations on 2-weeks-interval during the late term of pregnant sows with PEDV live vaccine. The B (LKK) group was applied that one time single PEDV live vaccine at the pre-mate followed by the TGEV PEDV combined inactivated vaccine (twice vaccination on 2-weeks interval at the third-trimester). C (KK) group was applied to sow which inoculated twice vaccination on 2-weeks-interval during the late term of pregnant sows with by the TGEV, PEDV combined inactivated vaccine. As the result of SN test on sows in the pig farm before vaccination, antibody titers was showed 9/45 (20.0%). By comparison with the serum neutralizing antibody titers against PEDV of the vaccination programs after PEDV of the vaccination, A group and B group vaccination method was higher than those of C group in sows. In the piglets up to 2 weeks of age, A group was showed antibody titers of 17/22 (81.8%) that showed 2-128, and B group was showed antibody titers of 30/37 (81.1%) that showed 2-512, and C group was showed antibody titers of 14/28 (50.0%) that showed 2-32. On the other hand, PEDV antibody titers were tested for the survey. As the results of SN test, Aujeszky's disease survey in 54 pig farms from november 2005 to august 2006, antibody titers of 47/286 (16.4%) showed above 2. Five breeding farms were antibody titers of 38/77 (49.4%), Wanggung zone farms antibody titers of 59/85 (69.4%). In pigs farms vaccinated the first of twice PEDV live vaccine, and after 6 month, the second of twice TGEV PEDV combined inactivated vaccine (LLKK, 256-1024 titer) method was higher than those of vaccinated twice the early term of pregnant, and twice the late term of pregnant sows of PEDV live vaccine (LLLL, 32 titer).

• 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.

• 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.

• Journal of Veterinary Science
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• v.22 no.4
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• pp.48.1-48.15
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• 2021

Background: Porcine epidemic diarrhea virus (PEDV) is a swine enteropathogenic coronavirus that has devastated the swine industry in South Korea over the last 30 years. The lack of an effective method to control the endemics has led to a surge in PEDV recurrences in affected farms throughout the country. Objectives: In the first step toward establishing systematic monitoring of and active control measures over the swine populations, we constructed an assessment model that evaluates the status of (1) biosecurity, (2) herd immunity, and (3) virus circulation in each of the PEDV-infected farms. Methods: A total of 13 farrow-to-finish pig farms with a history of acute PEDV infection on Jeju Island were chosen for this study. The potential risk of the recurrence in these farms was estimated through on-site data collection and laboratory examination. Results: Overall, the data indicated that a considerable number of the PEDV-infected farms had lax biosecurity, achieved incomplete protective immunity in the sows despite multi-dose vaccination, and served as incubators of the circulating virus; thus, they face an increased risk of recurrent outbreaks. Intriguingly, our results suggest that after an outbreak, a farm requires proactive tasks, including reinforcing biosecurity, conducting serological and virus monitoring to check the sows' immunity and to identify the animals exposed to PEDV, and improving the vaccination scheme and disinfection practices if needed. Conclusions: The present study highlights the significance of coordinated PEDV management in infected farms to reduce the risk of recurrence and further contribute towards the national eradication of PEDV.

• Korean Journal of Veterinary Service
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• v.37 no.2
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• pp.105-110
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• 2014

Porcine epidemic diarrhea virus (PEDV) is the causative agent of porcine epidemic diarrhea (PED) and causes a considerable economic loss in swine industry. In this study, the virucidal efficacy of the disinfectant composed to n-alkyl-dimethyl-benzyl-ammonium chloride (n-ADBAC) was investigated against PEDV. A virucidal efficacy was determined with the viability of PEDV contacted with the disinfectant in Vero cells. The disinfectant and PEDV were reacted on the hard water (HW) or organic matter suspension (OM) condition. On HW condition, PEDV was inactivated with 50 fold dilutions of the disinfectant. When the antiviral effect on OM condition was evaluated, the antiviral activity of the disinfectant showed on 10 fold dilutions against PEDV. As the disinfectant possesses the virucidal efficacy against PEDV, the disinfectant solution can be used to limit the spread of animal viral diseases.

• Journal of Plant Biotechnology
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• v.32 no.4
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• pp.263-268
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• 2005

Porcine epidemic diarrhea virus (PEDV) causes acute enteritis in pigs of all ages and is often fatal for neonates. In order to develop sweetpotato plants expressing PEDV antigen, we constructed the vector expressing spike gene of PEDV under the control of sweetpotato sporamin promoter or constitutive CaMV 35S promoter. The spike protein region of PEDV was synthesized by PCR and linked to each promoter, Transgenic sweetpotato [Ipomoea batatas (L.) Lam. cv. Yulmi] plants were developed from embryogenic calli following Agrobacterium tumefaciens-mediated transformation. The co-cultured embryogenic calli transferred to selective MS medium containing 1 mg/L 2,4-D, 100 mg/L kanamycin, and 400 mg/L claforan. These embryogenic calli were subcultured to the same selection medium at 3 weeks interval. Kanamycin-resistant calli transferred to hormone-free MS medium with kanamycin gave rise to somatic embryos and then converted into plantlets in the same medium. Southern blot analysis confirmed that the spike gene of PEDV was inserted into the genome of the sweetpotato plants. RT-PCR revealed that the spike gene of PEDV was highly expressed in transgenic sweetpotato plants.