• Korean Journal of Medicinal Crop Science
• /
• v.11 no.1
• /
• pp.24-30
• /
• 2003

Aqueous extracts from eleven species of Korean medicinal plants were screened for antiviral activity against transmissble gastroenteritis virus (TGEV) and porcine epidemic diarrhae virus (PEDV). Seven of eleven plant extracts were found to have cytotoxicity for ST cells at the concentration of 1mg/ml, and ten extracts except Ephedra sinica were found to have non-cytotoxicity for Vero cells at the same concentration, Extracts of Zanthoxylum piperium, Cudrina tricuspidata, Clerodendron trichomum, Sophora flavescens, effectively inhibited TGEV, respectively. There were the antiviral activity against TGEV in the extracts of Glesdistsia sinensis, Euonymus alatus, Ficus carica, Solanum nigrum, Ephedra sinica, Xanthium strumarium, Acanthopanax seeliflorus in spite of their cytotoxicities. Nine extracts except Xanthium strumarium and Acanthopanax seeliflorus were found to have the antiviral activitity against PEDV. Extracts of Zanthoxylum piperium, Sophora flavescens was shown to have antiviral activities against both TGEV and PEDV.

• Korean Journal of Veterinary Research
• /
• v.35 no.3
• /
• pp.515-530
• /
• 1995

Coronaviridae에 속하는 transmissible gastroenteritis virus(TGEV)와 porcine epidemic diarrhea virus(PEDV)를 specific하게 detection할 수 있는 방법을 개발하고자 본 연구를 수행하였다. 두 바이러스 모두 RNA 바이러스이기 때문에 reverse transcription-polymerase chain reaction(RT-PCR)으로 nucleocapsid(N) protein gene의 cDNA를 증폭시켰다. SmaI으로 처리한 pTZ19R에 ligation시킨 후 염기서열을 밝히고자 sequencing하였다. 각각의 prototype virus와 비교하여 상동성을 밝혔다. 두 바이러스에 대한 cDNA probe를 제작하여 Southern blot hybridization을 실시하였다. TGEV의 경우 백신주인 P45와 병독주인 Miller strain을 사용하였다. cDNA를 증폭시키기 위해 N1/N1R과 N2/N2R 두 가지 primer를 이용한 결과, N1/N1R primer의 경우 586bp 크기의 PCR product를 얻을 수 있었고, N2/N2R primers로 582bp의 cDNA를 증폭시킬 수 있었다. PEDV 실험을 위하여 PED 임상 증상을 나타내는 분변을 이용하여 RT-PCR을 실시하였다. P2/P2R primer로 753bp의 PCR product를 얻을 수 있었다. TGEV의 두 가지 strain의 N protein gene을 sequencing하여 prototype인 Purdue strain과 염기서열 상동성을 조사한 결과, 97%이상의 높은 homology를 나타내었다. PED-V 역시 N protein gene을 sequencing하여 CV777과 염기서열 상동성을 조사한 결과 97%이상의 homology로 PEDV임을 알 수 있었다. TGEV와 PEDV의 염기서열을 비교한 결과 29%의 낮은 homology를 관찰할 수 있었다. 두 가지 바이러스의 N protein gene에 대한 cDNA probe를 제작하여 Southern blot hybridization을 한 결과, 각 바이러스에 매우 특이적 반응을 나타내었다.

• Korean Journal of Veterinary Service
• /
• v.32 no.4
• /
• pp.293-298
• /
• 2009

Porcine respiratory coronavirus (PRCV) is antigenically related to transmissible gastroenteritis virus (TGEV). Differential serological diagnosis between PRCV and TGEV infection is not possible with the classical sero-neutralization test. Infection with PRCV or TGEV induces antibodies which neutralize both viruses to the same titer. However, the enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR) can differentiate between PRCV and TGEV infection. This study was carried out to investigate the prevalence of PRCV infection of swine in Gyeongnam province. A total of 391 serum samples from 37 herds in Gyeongnam were examined for antibody to PRCV using blocking ELISA. All serum samples were collected from 130- to 150-day-old pigs between August and December 2006. By ELISA, 182 out of 391 sera tested (46.5%) and 29 out of 37 sample herds (78.4%) were positive against PRCV. Our data suggested that seropositive herds for PRCV are distributed diffusely throughout Gyeongnam. The PCR methods were established to diagnose PRCV spike protein (S) gene. PCR were conducted to identify the PRCV genome against 150 pigs in PRCV antibody positive herds.

• Korean Journal of Veterinary Service
• /
• v.42 no.1
• /
• pp.9-15
• /
• 2019

Transmissible gastroenteritis (TGE) is a disease confined to pigs of all ages, and can be a significant cause of economic loss in breeding herds, primarily because of the very high piglet mortality. The causative agent is a coronavirus, an enveloped positive strand RNA virus and closely related but non-enteropathogenic porcine respiratory coronavirus (PRCV). Although the TGEV has declined with its innocent relative, PRCV, further genome changes could not be excluded. Therefore, the herd-level immunity against this virus is important for the prevention of disease and should be carefully monitored. The aim of this study is to develop monoclonal antibody capture enzyme-linked immunosorbent assay (MAC-ELISA) which can rapidly and accurately determine a large numbers of serum samples for surveillance purpose, and to compare the ELISA with a TGEV-specific serum neutralization test. The MAC-ELISA was sufficiently achieved, and the comparison with the virus-specific serum neutralization assays for 713 sera from pig farms showed a high correlation ($r^2=0.812$, P<0.001). The specificity and sensitivity of MAC-ELISA for the serum neutralization test 91.9% and 91.6%, respectively, which means that the antibody detected by the MAC-ELISA could be said to be protective antibodies. In conclusion, the developed MAC-ELISA would be very helpful in evaluating protective antibodies against TGEV.

• Korean Journal of Veterinary Research
• /
• v.53 no.4
• /
• pp.217-224
• /
• 2013

Transgenic plants have been tested as an alternative host for the production and delivery of experimental oral vaccines. Here, we developed transgenic potatoes that express the major antigenic sites A and D of the glycoprotein S from transmissible gastroenteritis coronavirus (TGEV-$S_{0.7}$) under three expression vector systems. The DNA integration and mRNA expression level of the TGEV-$S_{0.7}$ gene were confirmed in transgenic plants by PCR and northern blot analysis. Antigen protein expression in transgenic potato was determined by western blot analysis. Enzyme-linked immunosorbent assay results revealed that based on a dilution series of Escherichia coli-derived antigen, the transgenic line P-2 had TGEV-$S_{0.7}$ protein at levels that were 0.015% of total soluble proteins. We then examined the immunogenicity of potato-derived TGEV-$S_{0.7}$ antigen in mice. Compared with the wild-type potato treated group and synthetic antigen treated group, mice treated with the potato-derived antigen showed significantly higher levels of immunoglobulin (Ig) G and IgA responses.

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

• Korean Journal of Microbiology
• /
• v.52 no.2
• /
• pp.140-147
• /
• 2016

A process for manufacturing virally-safe porcine bone hydroxyapatite (HA) has been developed to serve as advanced xenograft material for dental applications. Porcine bone pieces were defatted with successive treatments of 30% hydrogen peroxide and 80% ethyl alcohol. The defatted porcine bone pieces were heat-treated in an oxygen atmosphere box furnace at $1,300^{\circ}C$ to remove collagen and organic compounds. The bone pieces were ground with a grinder and then the bone powder was sterilized by gamma irradiation. Morphological characteristics such as SEM (Scanning Electron Microscopy) and TEM (Transmission Electron Microscopy) images of the resulting porcine bone HA (THE Graft$^{(R)}$) were similar to those of a commercial bovine bone HA (Bio-Oss$^{(R)}$). In order to evaluate the efficacy of $1,300^{\circ}C$ heat treatment and gamma irradiation at a dose of 25 kGy for the inactivation of porcine viruses during the manufacture of porcine bone HA, a variety of experimental porcine viruses including transmissible gastroenteritis virus (TGEV), pseudorabies virus (PRV), porcine rotavirus (PRoV), and porcine parvovirus (PPV) were chosen. TGEV, PRV, PRoV, and PPV were completely inactivated to undetectable levels during the $1,300^{\circ}C$ heat treatment. The mean log reduction factors achieved were $${\geq_-}4.65$$ for TGEV, $${\geq_-}5.81$$ for PRV, $${\geq_-}6.28$$ for PRoV, and $${\geq_-}5.21$$ for PPV. Gamma irradiation was also very effective at inactivating the viruses. TGEV, PRV, PRoV, and PPV were completely inactivated to undetectable levels during the gamma irradiation. The mean log reduction factors achieved were $${\geq_-}4.65$$ for TGEV, $${\geq_-}5.87$$ for PRV, $${\geq_-}6.05$$ for PRoV, and $${\geq_-}4.89$$ for PPV. The cumulative log reduction factors achieved using the two different virus inactivation processes were $${\geq_-}9.30$$ for TGEV, $${\geq_-}11.68$$ for PRV, $${\geq_-}12.33$$ for PRoV, and $${\geq_-}10.10$$ for PPV. These results indicate that the manufacturing process for porcine bone HA from porcine-bone material has sufficient virus-reducing capacity to achieve a high margin of virus safety.

• Journal of Veterinary Clinics
• /
• v.23 no.3
• /
• pp.300-307
• /
• 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 Research
• /
• v.38 no.2
• /
• pp.336-344
• /
• 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.

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