• Korean Journal of Veterinary Service
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• v.39 no.2
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• pp.117-124
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• 2016

In this study, the virucidal efficacy of a fumigant containing 20% ortho-phenylphenol against classical swine fever virus (CSFV) and porcine reproductive and respiratory syndrome virus (PRRSV) was examined. After each carrier deposited with CSFV and PRRSV suspensions was exposed to the fumigant in a $25-m^3$ test room for 15 h, all carriers were neutralized and diluted, and each diluted suspension was inoculated into each proper cell line. After incubation, CSFV and PRRSV viability in each cell line was examined and 50% tissue culture infectious dose $(TCID_{50})/mL$ was calculated. In the results, the concentration of viable virus in all of pathogen control-carriers was more than $2{\times}10^5TCID_{50}/mL$, and there were no cytotoxicity in all of toxicity control-carriers. In addition, the fumigant inactivated ${\geq}4.8{\log}_{10}(TCID_{50}/mL)$ of both CSFV and PRRSV. These findings will be useful for preventing the spread of CSFV and PRRSV infection.

• Korean Journal of Veterinary Service
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• v.31 no.1
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• pp.71-77
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• 2008

Today swine respiratory disease is one of the most important diseases because of its economic losses and severe infection nationwide, and swine society as well as veterinary service are trying to prevent the diseases in Korea. This study would like to obtain some information useful for the control of the diseases. A total of 174 lung specimens with lesion consisted of 3 sorts; 60 were collected from nursey pigs requested for diagnostic service from March of 2006 to October of 2007, 58 finishing pigs and 56 sows were selected from slaughterhouse from September to November 2007. In the detection test of pathogens by PCR, porcine circovirus 2 (PCV2), porcine reproductive and respiratory syndrome virus (PRRSV) and Mycoplasma hyopneumoniae were positive in 95.4%, 31.6%, and 20.1%, respectively. Double infection rate with PCV2 and PRRS was 30.4%, PCV2 and M hyopneumoniae was 19.5%, triple infection with PCV2, PRRS and M hyopneumoniae was 5.7%, respectively.

• Korean Journal of Veterinary Service
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• v.36 no.2
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• pp.139-145
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• 2013

Porcine respiratory disease complex (PRDC) continues to be a significant economic problem to the swine industry. In order to elucidate the etiology of PRDC including porcine circovirus type 2 (PCV2), porcine reproductive and respiratory disease syndrome virus (PRRSV), swine influenza virus (SIV), Mycoplasma hyopneumoniae (MH), Pasteurella multocida (PM) and Actinobacillus pleuropneumoniae (APP) in Namwon, the 455 lung samples were randomly collected from slaughtered pigs, examined gross lesions indicative of respiratory disease of lung and classified the lung lesion according to the severity of lung lesions. Two hundred pigs lung tissues with pneumonic lesions were examined for pathogen by PCR. As a result, the numbers of pneumonic lesions were 357 (78.5%), mean pneumonic score ($mean{\pm}SD$) was $2.03{\pm}0.90$ and the highest gross lesion according to stages was 1 (11~20%). In detection of pathogens, PCV2, PRRSV, SIV, MH, APP and PM were positive in 76.5%, 5.0%, 6.0%, 9.0%, 4.5% and 6.0%, respectively and PCV2-MH was the most detected causative pathogens of PRDC in co-infection. In the serological test for PRRSV, PCV2, MH, APP2, APP5, HP and PM, showed high antibody positive rates 93% or more.

• Korean Journal of Veterinary Research
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• v.47 no.4
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• pp.425-428
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• 2007

From January to June 2006, 54 suckling pigs had been submitted in virology lab., College of Veterinary Medicine, Seoul National University. All pigs had suffered from various symptoms such as respiratory sign, enteric signs, neurologic signs, etc. Among 54 pigs, 24 pigs (44.4%) were positive for porcine hemagglutinating encephalomyelitis virus (HEV) through reverse transcription-nested polymerase chain reaction. According to this result, HEV infections seemed to be prevalent and widespread in Korean swine farms, and the infection is associated with respiratory signs and neurologic signs more than enteric signs. The HEV positive pigs showing respiratory signs were co-infected with viruses such as PRRSV, and PCV2, or bacteria such as Pasteurella spp. The single infection may subclinically have an influence on outbreak of other respiratory pathogens in suckling pigs.

• Korean Journal of Veterinary Research
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• v.39 no.1
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• pp.111-117
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• 1999

A nation wide sero-epidemiological survey of porcine reproductive and respiratory syndrome(PRRS) was carried out to analyze the current status of the PRRS virus infections in the field using the indirect immunofluorescent antibody assay(IFA) with the field isolate PL96-1. Since the first report of the antibody detection to PRRSV in 1993, the prevalence of seropositive pigs has increased dramatically and the data indicate that over 21% of the pigs and around 60% of the farms showed seropositives to the PRRS virus. A slightly higher positive rate was recognized in breeders than fattenings and it might be due to the higher age at the time of testings. No significant regional differences were detected in the sero-epidemiological survey. Higher sero-positive rate in growers indicates that PRRSV infection in the field was common after weaning(around 40 days). However, the number of seropositive pigs were declined in fattening pigs. Sows showed around 26% of sero-positive rate that there is a higher chance of continuous virus circulation in the infected farms. Low rate of sero-positivity in boars(9.8%) implies that there is high demand in proper control measures to prevent virus spreading through breeding procedures such as natural or artificial insemination. Therefore it was concluded that PRRSV infection in domestic swine herds is endemic and the positive rate and economic loses will be increased by spontaneous infections in naive farms.

• Journal of Veterinary Science
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• v.21 no.5
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• pp.79.1-79.12
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• 2020

Background: Recently, the pork industry of Thailand faced an epidemic of highly virulent strains of porcine reproductive and respiratory syndrome virus (PRRSV), which spread throughout Southeast Asia, including the Lao People's Democratic Republic and Cambodia. Hence, the rapid and on-site screening of infected pigs on a farm is essential. Objectives: To develop the new aptamer as a biosensor for detection PRRSV which are rapid and on-site screening of infected pig. Methods: New aptamers against PRSSV were identified using the combined techniques of capillary electrophoresis, colorimetric assay by gold nanoparticles, and quartz crystal microbalance (QCM). Results: Thirty-six candidate aptamers of the PRRSV were identified from the systematic evolution of ligands by exponential enrichment (SELEX) by capillary electrophoresis. Only 8 out of 36 aptamers could bind to the PRSSV, as shown in a colorimetric assay. Of the 8 aptamers tested, only the 1F aptamer could bind specifically to the PRSSV when presented with the classical swine fever virus and a pseudo rabies virus. The QCM was used to confirm the specificity and sensitivity of the 1F aptamer with a detection limit of 1.87 × 10¹⁰ particles. Conclusions: SELEX screening of the aptamer equipped with capillary electrophoresis potentially revealed promising candidates for detecting the PRRSV. The 1F aptamer exhibited the highest specificity and selectivity against the PRRSV. These findings suggest that 1F is a promising aptamer for further developing a novel PRRSV rapid detection kit.

• Korean Journal of Veterinary Service
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• v.37 no.1
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• pp.1-9
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• 2014

Although it has been generally accepted that porcine reproductive and respiratory syndrome virus (PRRSV) induces weak and delayed protective immunity after infection, it is unclear that the same immunological features can be applicable to all PRRS viruses because huge genetic variation exists even among the same genotypes of PRRSV (Type 1 and 2). In the current study, two genetically distinct type 2 PRRSV strains (VR-2332 and JA142) which showed approximately 90% nucleotide homology based on ORF5 sequences were characterized by both in vitro and in vivo assessments to determine the immunological features of the viruses. For in vitro assessment, porcine alveolar macrophages (PAM) were infected with the viruses at $10^{-3}$ multiplicity of infection (MOI) and then supernatants and cells were collected separately at 36 hrs post infection to determine the relative expression levels of IL-$1{\alpha}$, IL-12, TNF-${\alpha}$ and INF-${\alpha}/{\beta}$ by quantitative RT-PCR. In addition, five PRRSV-free pigs were inoculated with either of JA142 or VR2332 for in vivo assessment. Serum samples were collected every week until 6 weeks post challenge. The serum samples were analyzed for the levels of viremia, PRRSV nucleocapsid-specific antibody and virus neutralizing antibody. Based on those assessments, the two viruses showed different patterns of cytokine expression in PAM and immune responses in pigs after infection. These results indicate that genetically distinct PRRSV strains have different immunological features, which might be criteria for virus classification and selection of candidate virus strains for vaccine development in the future.

• Journal of the korean veterinary medical association
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• v.46 no.3
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• pp.279-287
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• 2010

돼지 번식기 및 호흡기 증후군 ( PRRS ; Porcine Reproductive and Respiratory Syndrome )은 우리나라를 포함한 전세계적으로 양돈산업에 가장 심각한 경제적인 손실을 끼치고 있는 질병으로, 조사자료에 의하면 미국의 경우 년간 손실 금액이 약 6천5백억(미화 560백만 달러)에 이르는 것으로 추정된다. 최근 우리나라도 피해의 정도가 정확히 조사 된 바가 없으나 현장의 골칫거리로 아직도 인식되어 다양한 시도 (Depop, Multi-site, Stabilization, etc)를 통해 사안별로 조치들을 하지만 발생정도는 줄어들지 않고 있다. 따라서 최근 차단방역에 대한 미국의 자료를 소개하오니 양돈현장 수의사들에게 도움이 되었으면 한다.

• Korean Journal of Veterinary Research
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• v.43 no.3
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• pp.463-469
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• 2003

Eight nursery to grower pigs exhibiting weight loss and sudden death were diagnosed as postweaning multisystemic wasting syndrome (PMWS) based on the results of gross findings, histopathology, immunohistochemistry, fluorescent antibody test, virus isolation, PCR, serology, and electron microscopy. Groosly, the pigs had a rough hair coats and were severely emaciated. And moot lymph nodes were pale and enlarged. Lungs were not fully collapsed and exhibited 10 to 40% pale red cranioventral consolidation. Histopathologically, typical lymphohistiocytic interstitial to bronchointerstitial pneumonia, chronic lymphadenitis, severe lymphoid depletion, and basophilic intracytoplasmic inclusions were noted in the most lymphoid tissues. Porcine circovirus panicles were observed in the inguinal lymph node of the pigs by electron microscopy. Porcine circovirus type 2 (PCV2) antigens or viral DNAs were detected in the lesions of all pigs using immunohistochemistry or PCR. Two PCV2 were isolated from a homogenate of pooled lung and lymph node in 2 of the 5 pigs. Additionally, antigens of porcine reproductive and respiratory syndrome virus (PRRSV) and Hemophilus (H.) parasuis were also detected by immunofluorescent antibody test. Serologically, 55% of randomly selected sows and fattening pigs was serum antibody positive to PCV2 by an indirect fluorescent antibody (IFA) test and approximately 18 % of animals in the herd were serologically pooitive by the ELISA kit for PRRSV. To our knowledge, this is the first report of PMWS co-infected with PCV-2, PRRS, and H. parasuis in Korea.

• Korean Journal of Veterinary Research
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• v.49 no.3
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• pp.215-220
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• 2009

The prevalence of potentially xenozoonotic viruses in the reproductive tract of female pigs in Korea was investigated by polymerase chain reaction (PCR). These viruses include porcine endogenous retrovirus (PERV), porcine reproductive and respiratory syndrome virus (PRRSV), swine hepatitis E virus (SHEV), porcine lymphotropic herpesvirus (PLHV), and porcine circovirus type 2 (PCV-2). Histopathological examination and PCR analysis were conducted using the ovaries of 70 slaughtered pigs that were collected from 14 farms in Jeju. Histopathologically, infiltrations of mononuclear inflammatory cells around the thick-walled coiled vessels in the ovarian medulla were observed in 15 cases. Based on the PCR method, PERV, PLHV, PRRSV, SHEV, and PCV-2 were detected in 69 (98.6%), 35 (50%), 5 (7.1%), 4 (5.7%), and 1 sample (1.4%), respectively. These results suggest that PERV and PLHV are the major xenozoonotic viruses in the porcine ovary. This study should aid in the development of a monitoring protocol for potential xenozoonotic agents and in the production of germ-free pigs for xenotransplantation.