• Korean Journal of Veterinary Research
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• v.38 no.2
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• pp.336-344
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• 1998

Eight monoclonal antibodies(MAbs) against the transmissible gastroenteritis virus (TGEV) were produced and characterized. Four of the MAbs were produced against a reference TGEV, Purdue strain(P115) and the others were produced against the Korean vaccine virus, Pyungtaek strain. Only one MAb(5C8) produced against P115 had neutralizing activity and was found to be E2 protein-specific. The other seven MAbs(4E2, 4G8, 5H6, 1F8, 2C6, 5H5, and 3A6) had specificity of nucleocapsid protein and no neutralizing activity. All MAbs reacted with different strains of TGEV, but none of the MAbs was reactive with porcine enteropathogenic viruses such as rotavirus, epidemic diarrhea virus and enterovirus by fluorescence antibody(FA) test.

• Journal of Veterinary Clinics
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• v.23 no.3
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• pp.300-307
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• 2006

In the present study, methods of the reverse transcription-polymerase chain reaction(RT-PCR) were evaluated for the rapid detection and differentiation of transmissible gastroenteritis virus(TGEV), porcine epidemic diarrhea virus(PEDV) and rotavirus in piglets suffering from diarrhea. For the purposes, the PCR conditions were first confirmed for the amplification of VP7 gene of rotavirus and N gene of TGEV and PEDV using each specific primers and their annealing temperature. Multiplex RT-PCR methods were further determined to distinguish these viral infections and the results are as follows. For the specific amplification of these viral genes, the reliable PCR condition was determined as 30 cycles of reaction consisting each 1 min of denature at $94^{\circ}C$, annealing at $42^{\circ}C$ and polymerization at $72^{\circ}C$ with 1.0 mM $MgCl_2$. It was able to differentiate these viral infections in the intestines and feces of piglets suffering from diarrhea by duplex PCR for TGEV and PEDV and single PCR for rotavirus with a primer-annealing temperature of $42^{\circ}C$. When the multiplex RT-PCR were undertaken for the field samples, 17 cases of PEDV and 5 cases of rotavirus infections were differential diagnosed in a total of 92 samples of intestines and feces of the piglets with diarrhea.

• 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 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.

• Journal of Veterinary Clinics
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• v.26 no.5
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• pp.463-466
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• 2009

A swine farm located in the Kyungpook province (designated as farm D that have been suffering from PED for several years was selected to study the etiology and the outbreak pattern of PED by clinical and laboratory examinations. Clinical examination indicated that sows exhibited signs of mastitis resulting in an inadequate transfer of lactogenic immunity against PEDV to newborn piglets. Furthermore, serological tests revealed that all sow groups and their piglets had low levels of anti-PEDV antibody. These data suggest that improper vaccination program has been indeed performed in this farm. Remarkably, despite no symptoms of PED in weaners, the presence of PEDV was identified by RT-PCR from fecal samples of weaning piglets, indicating persistent PEDV circulation in the herd. Based on these results, the following basic control schemes were executed for the control of PEDV circulation in the farm; a) A quick removal of affected pigs and disinfection of affected sheds. b) restructuring of vaccination program and employment of consultant. c) prompt treatment of mastitis and removal of poor lactogenic sows, and d) enhancement of biosecurity of farrowing house by acquisition of additional space. We evaluated risk factors and implementation of control measures in two months and were unable to found any case related to PEDV infection. Taken together, our data indicate that the method described above is effective for the control of PED outbreak in farm persistently suffering from PEDV infection.

• 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.31 no.1
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• pp.101-111
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• 2008

The purpose of this study was to investigate the protective effects against porcine epidemic diarrhea virus (PEDV) and transmissible gastroenteritis virus (TGEV) in suckling piglets by oral administration of IgY. Twenty piglets were divided into two groups with the same number: group I (treated with IgY) and group II (not treated). Group I was administerd orally with IgY for three days from one-day-old and experimentally challenged with PEDV and TGEV at four-day-old. The other was administered with saline solution and challenged with PEDV and TGEV at four-day-old. Serum antibody titers against PEDV and TGEV were examined by enzyme-linked immunosorbent assay (ELISA) and the detection of PEDV or TGEV antigen from feces and small intestines was performed by reverse transcription-polymerase chain reaction (RT-PCR) and indirect immunofluorescence (IFA). The antibody titers of the group I was higher than that of the other, and lasted at the end of experiment. In the detection tests of both virus from feces and small intestine, the rate of the group I was lower. Based on these results, oral administration of IgY may be effective to prevent the diarrhea caused by PEDV and TGEV.

• Journal of Plant Biotechnology
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• v.35 no.1
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• pp.87-94
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• 2008

Porcine epidemic diarrhea virus (PEDV) is an infectious and highly contagious virus of swine. In order to develop the transgenic tobacco culture cells producing PEDV antigen protein, four vectors expressing PEDV spike protein (SP) gene under the control of a CaMV 35S promoter were constructed. Four fragments of the SP region of PEDV, SP1 (444 bp, 1487-1930 bp), SP2 (1.7 kb, 2300-3987 bp), SP3 (1.4 kb, 1559-2950 bp), and SP4 (2.6 kb, 9-2643 bp) were amplified by PCR and then C-MYC tag was fused to the end of each SP gene, respectively. These cassettes are inserted into the pCAMBIA2300 (named as 35S::SP1-M, 35S::SP2-M 35S::SP3-M, and 35S::SP4-M, respectively). Tobacco (cv. BY-2) cultured cells were transformed by co-cultivation with Agrobacterium tumefaciens harboring expression vector. We selected kanamycin-resistant calli and checked for the presence of the introduced SP gene using PCR, resulting 70% of them showed the foreign gene. We selected the lines with high-level expression of PEDV antigen protein based on dot blot analysis. Southern blot analysis confirmed that the PEDV SP gene was integrated into the genome of the tobacco cultured cells. Northern blot analysis showed that the introduced gene was highly expressed in transgenic cultured cells. Transgenic tobacco cultured cells-derived antigen induced immunogenicity in mice as determined by a plaque reduction neutralization assay. These results suggest that the vectors expressing PEDV spike protein gene in this study will be useful for the development of transgenic plants and cultured cells producing PEDV antigene protein.

• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2006.06a
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• pp.27.1-27.1
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• 2006

• Korean Journal of Veterinary Service
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• v.31 no.1
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• pp.113-128
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• 2008

The purpose of this study was to investigate the protective effects against porcine epidemic diarrhea virus (PEDV) and transmissible gastroenteritis virus (TGEV) in suckling piglets by oral administration of the IgY. The piglets were divided into two groups: test and control group. The former (n=10) were administered orally with IgY for three days from one-day-old and experimentally challenged with PEDV and TGEV at four-day-old. The latter (n=10) were administered with saline solution and challenged with same methods. Several tests were studied and summarized as follows; In clinical signs, the piglets of the control group showed the typical signs such as severe watery diarrhea, depression and anorexia but those of the test group recovered progressively. Control group showed 20% in mortality, but there were no death in the other. The gross lesions in the test were milder than those in the control, and there were typical findings as like congestion and distension of lumen in the control group. In histopathological study, the piglets of the control group had shortened and fused intestinal villi and a marked loss of epithelium, whereas the others showed milder changes. It could be concluded that oral administration of IgY, specific yolk-antibody against PEDV and TGEV is effective to prevent PEDV and TGEV infection in suckling piglets.