• Journal of Veterinary Science
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• v.21 no.5
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• pp.80.1-80.13
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• 2020

Background: In suckling piglets, transmissible gastroenteritis virus (TGEV) causes lethal diarrhea accompanied by high infection and mortality rates, leading to considerable economic losses. This study explored methods of preventing or inhibiting their production. Bovine antimicrobial peptide-13 (APB-13) has antibacterial, antiviral, and immune functions. Objectives: This study analyzed the efficacy of APB-13 against TGEV through in vivo and in vitro experiments. Methods: The effects of APB-13 toxicity and virus inhibition rate on swine testicular (ST) cells were detected using 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT). The impact of APB-13 on virus replication was examined through the 50% tissue culture infective dose (TCID₅₀). The mRNA and protein levels were investigated by real-time quantitative polymerase chain reaction and western blot (WB). Tissue sections were used to detect intestinal morphological development. Results: The safe and effective concentration range of APB-13 on ST cells ranged from 0 to 62.5 ㎍/mL, and the highest viral inhibitory rate of APB-13 was 74.1%. The log₁₀TCID₅₀ of 62.5 ㎍/mL APB-13 was 3.63 lower than that of the virus control. The mRNA and protein expression at 62.5 ㎍/mL APB-13 was significantly lower than that of the virus control at 24 hpi. Piglets in the APB-13 group showed significantly lower viral shedding than that in the virus control group, and the pathological tissue sections of the jejunum morphology revealed significant differences between the groups. Conclusions: APB-13 exhibited good antiviral effects on TGEV in vivo and in vitro.

• Journal of Microbiology and Biotechnology
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• v.30 no.4
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• pp.515-525
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• 2020

Interferon (IFN)-λ plays an essential role in mucosal cells which exhibit strong antiviral activity. Lactobacillus plantarum (L. plantarum) has substantial application potential in the food and medical industries because of its probiotic properties. Alphacoronaviruses, especially porcine epidemic diarrhea virus (PEDV) and transmissible gastroenteritis virus (TGEV), cause high morbidity and mortality in piglets resulting in economic loss. Co-infection by these two viruses is becoming increasingly frequent. Therefore, it is particularly important to develop a new drug to prevent diarrhea infected with mixed viruses in piglets. In this study, we first constructed an anchored expression vector with CWA (C-terminal cell wall anchor) on L. plantarum. Second, we constructed two recombinant L. plantarum strains that anchored IFN-λ3 via pgsA (N-terminal transmembrane anchor) and CWA. Third, we demonstrated that both recombinant strains possess strong antiviral effects against coronavirus infection in the intestinal porcine epithelial cell line J2 (IPEC-J2). However, recombinant L. plantarum with the CWA anchor exhibited a more powerful antiviral effect than recombinant L. plantarum with pgsA. Consistent with this finding, Lb.plantarum-pSIP-409-IFN-λ3-CWA enhanced the expression levels of IFN-stimulated genes (ISGs) (ISG15, OASL, and Mx1) in IPEC-J2 cells more than did recombinant Lb.plantarum-pSIP-409-pgsA'-IFN-λ3. Our study verifies that recombinant L. plantarum inhibits PEDV and TGEV infection in IPEC-J2 cells, which may offer great potential for use as a novel oral antiviral agent in therapeutic applications for combating porcine epidemic diarrhea and transmissible gastroenteritis. This study is the first to show that recombinant L. plantarum suppresses PEDV and TGEV infection of IPEC-J2 cells.

• Korean Journal of Veterinary Research
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• v.37 no.2
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• pp.339-347
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• 1997

A cytopathogenic virus was isolated from the brain tissues of pig showing ataxia. The biophysical, morphological and serological assay showed that the isolate belongs to a coronavirus. The differential identification of the isolate with monoclonal antibodies against A and X sites of transmissible gastroenteritis virus indicated that the virus has a characteristics of porcine respiratory coronavirus. The RT-PCR on nucleocapsid region of TGEV also showed that the isolate has the same conserved sequence. The diverse pathogenesis of PRCV and its implication in field were discussed.

• Korean Journal of Veterinary Service
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• v.22 no.3
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• pp.239-245
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• 1999

The reverse transcriptase polymerase chain reaction (RT-PCR) was used for the detection of bovine coronavirus (BCV) in fecal samples by using reverse transcriptase and two primers which flanked M gene sequence of 407bp. RT-PCR detected bovine coronavirus specifically, but did not detect mouse hepatitis virus (MHV), transmissible gastroenteritis virus (TGEV), and bovine rotavirus (BRV). The M gene sequences of MHV are homologus to that of BCV, but minor differences exist in the primer regions, preventing annealing of the primers. Detection of BCV using RT-PCR was compared with ELISA and the agreement of BCV detection by RT-PCR and ELISA was 95.3%. RNA detection in positive clinical specimens was significantly better by PCR than immunological detection of BCV by ELISA.

• Proceedings of the Korean Society of Veterinary Pathology Conference
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• 2002.11a
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• pp.143-143
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• 2002

돼지 장염 바이러스를 동시에 감별 진단할 수 있는 새로운 진단법인 oligonicleotide microarray 기법을 돼지 설사 분변을 대상으로 바이러스 감염을 진단하고 기존의 진단법으로 널리 사용되고 있는 RT-PCR과 진단기법의 민감도와 특이도를 비교하고자 하였다. 32개 양돈장, 102 예의 포유 및 이유자돈의 설사분변에서 microarray를 이용한 검사결과 Transmissible gastroenteritis virus (TGEV) 9.8％, porcine epidemic diarrhea virus (PEDV) 28％, (porcine enteric calicivirus (PECV) 18.6％, porcine rotavirus (PRV) group A 6.9％, PRY group C 1％ 의 검출률을 확인하였다. 또한 RT-PCR 기법과의 비교에서도 100％의 민감도와 72.2％의 특이도를 보였으며 agreement는 85.3％, kappa value 0.71로 우수한 진단기법임을 확인하였다. 이를 통해 microarray 진단법은 RT-PCR 후의 전기영동 과정과 민감도를 높이기 위해 수행되는 nested PCR 수행의 번거러움을 없애면서 정확한 감별진단을 수행할 수 있는 진단 기법임을 확인하였다.

• Proceedings of the Korean Society of Veterinary Pathology Conference
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• 2002.11a
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• pp.142-142
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• 2002

돼지의 주요 장염 유발 바이러스인 돼지 전염성 위장염 바이러스 (transmissible gastroenteritis virus; TGEV), 돼지 유행성 설사증 바이러스 (porcine epidemic diarrhea virus; PEDV), 돼지 칼리시 바이러스 (porcine enteric calicivirus; PECV), 돼지 로타바이러스 A 형과 C 형 (porcine rotavirus; PRY, group A and C)을 동시에 감별 진단 할 수 있는 신속하고 정확한 oligonucleotide microarray 진단법을 개발하였다. 이 진단법은 유리슬라이드에 각각의 바이러스에 특이적인 부위에서 제작된 oligonucleotide probe를 찍은 DNA chip을 제작하여 여기에 각각의 바이러스를 역전사하고 cy5-dCTP를 포함한 multiplex PCR을 수행한 다음 hybridization 하였다. 이후 hybridization 결과는 fluorescence scanner를 이용하여 확인하였다. 이 새로운 microarray system은 RT-PCR과 같은 기존의 진단방법보다 소량의 바이러스를 민감하게 검사할 수 있을 뿐 아니라 hybridization을 통해 검사결과의 정확성을 확인할 수 있었다. 따라서 본 연구에서 개발한 microarray system은 돼지의 설사 유발 바이러스를 진단하는데 매우 유용한 진단 방법임을 확인하였다.

• Korean Journal of Veterinary Service
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• v.24 no.3
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• pp.255-262
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• 2001

Five pigs industry with outbreaks of transmissible gastroenteritis(TGE) in Gyeongbuk province were investigated during the period from January to December 2000. The typical signs of TGE in piglets had transient vomiting and a watery yellowish diarrhea, rapid loss of weight, dehydration and high mortality in pigs under 2 weeks of age. Clinical signs of TGE in growing and finishing pigs and sows were usually limited to inappetence and diarrhea for one or a few days, with vomiting observed in an occasional animal. The detection of TGE viral antigen in epithelial cells of the small intestine had been used in indirect fluorescent antibody test (IFA) for diagnosing TGE in young pigs. WかR had been successfully used to detect the DNA derived from TGEV in specimen of intestinal swabs. Among 5 pigs industry, four showed typical signs of epizootic TGE and one progressing enzootic TGE. It was 22～53 days that the duration of initial clinical disease in TGE outbreaks of pigs investigated in Gyeongbuk province in 2000. However the duration related directly to herd size. Mortality of piglets under 2 weeks of age for duration was 53.2～88.2%, but that of piglets 2～5 weeks of age was 2.5～6.5%. The piglets of 1 weeks of age died mostly during duration of TGE, but varied considerably with husbandry and other environmental factors.

• Proceedings of the Korean Society of Veterinary Pathology Conference
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• 2003.10a
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• pp.32-32
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• 2003

Intestinal infections are common in growing pigs and can be caused by multiple pathogens, environmental and management factors [1]. Among the most important viruses in swine enteritis are porcine epidemic diarrhea virus (PEDV), transmissible gastroenteritis virus (TGEV), porcine enteric calicivirus (PECV), porcine group A rotavirus (PRV gp A) and bacteria are Escherichia coli and Salmonella spp. and protozoa is Isospora suis [1]. The DNA chip system can serve as a powerful tool that can be utilized for simultaneous detection of specific pathogenic bacteria strains and viruses [2,3]. The combination of PCR and DNA chip technology will provide a novel method for the detection of porcine enteric pathogens thus revolutionize the diagnosis and management of the disease. The aim of this study is to develop DNA chip system for the rapid and reliable detection of five major porcine enteric pathogens based on oligonucleotide DNA chip hybridization. (omitted)

• 한국생물공학회:학술대회논문집
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• 2005.04a
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• pp.203-206
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• 2005

TGE (Transmissible Gastroenteritis) caused by a virus belonging to family coronavirus, results in an acute infection of the small intestine of the pig. The optimum operation variables such as multiplicity of infection (MOI), infection time and harvest time were investigated for TGE vaccine production by immobilized ST(swine testicle) cells. In the culture supplemented with 5% serum, maximum virus titer of $1.2{\times}10^6pfu/ml$ was obtained at the conditions of 0.01 MOI, 2day infection time, and 1 day harvest time. Serum is a potential source of bacterial, mycoplasmal and viral contamination, and it has a possibility of the introduction of serum proteins, prion and pyrogens into the final product. For these reasons, much attention has been focused on the development of serum-free media. A new serum-free media (SFM) has been developed in order to produce TGE vaccine of high quality with low cost. The performance of SFM developed was compared with other commercially available serum-free media and serum supplemented media in terms of virus productivity. The cultures with serum-free media showed higher titer than that with serum supplemented media. Among various serum-free media tested, CHO-S-SFMII showed highest virus titer.

• Korean Journal of Veterinary Research
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• v.44 no.2
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• pp.259-268
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• 2004

Porcine circovirus type 2 (PCV-2) has been associated with various disease in pigs worldwide including postweaning multisystemic wasting syndrome (PMWS) and porcine dermatitis and nephropathy syndrome (PDNS). In this study, monoclonal antibodies (MAbs) against PCV were produced, characterized and applications of MAbs as diagnostic reagents were described. Spleen or lymph node cells from BALB/c mouse immunized respectively with PCV-1, PCV-2 or expressed PCV-2/ORF2 proteins in baculovirus were fused with SP2/0 myeloma cells using polyethylene glycol (PEG) and hybridoma cells producing PCV-1 or PCV-2-specific antibody were screened by an indirect immunofluorescence (IIF) test. A total of fifteen MAbs were produced against PCV. Six MAbs were PCV-1-specific and nine were PCV-2-specific. All PCV-1-specific MAbs reacted with only PCV-1 and all PCV-2-specific MAbs were reactive with only PCV-2 by IIF test. None of the MAbs was reactive with porcine reproductive and respiratory syndrome virus (PRRSV), porcine parvovirus (PPV), porcine rotavirus (PRV), and transmissible gastroenteritis virus (TGEV). Some PCV-2-specific MAbs recognized the PCV-2 infected porcine tissues by IIF or immunohistochemistry (IHC) assay. From this experiment, it was confirmed that MAbs produced in this study were PCV-specific and could be used as reliable diagnostic reagents for PCV-1/PCV-2 detection and differentiation.