• 한국동물위생학회지
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• 제27권3호
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• pp.281-288
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• 2004

As all other intensively farmed domestic species, most mortality in ostriches is closely to rearing conditions. While ostriches is also highly sensitive to stress, species-specific infectious disease play only a minor role. But investigation of ostrich's disease is not peformed almost in Korea. The study was performed to investigate the titers of antibody for Newcastle disease(ND), Infectious bronchitis(IB), Egg drop syndrome '76(EDS), Avian influenza(AI), salmonellosis, Mycoplasma gallisepticum infection(MG), Mycoplasma synoviae infection(MS), Infectious bursal disease(IBD), Brucellosis, Toxoplasmosis, Japanese encephalitis(JE), Porcine parvovirus infection, Encephalomyocarditis and Porcine reproductive respiratory syndrome (PRRS). The results obtained in the 62 ostrich sera slaughtered in Gyeongbuk province were summarized as follows: The average of antibody positive rates to ND, IB, EDS, AI(H9Nl), JE, Porcine parvovirus infection and Encephalomyocarditis by HI test were $75.8\%,\;100\%,\;0\%,\;0\%,\;51.6\%,\;50\%\;and\;56.5\%$ respectively. The antibody positive rates to salmonellosis, MG, MS by plate agglutination test were $12.9\%,\;25.8\%,\;and\;0\%$ respectively. Antibodies to disease agent such as IBD and AI by agar gel precipitation(AGP) test, Brucellosis by tube agglutination, toxoplasmosis by latex agglutination test and PRRS by IFA were all negative.

• 대한수의학회지
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• 제34권1호
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• pp.77-83
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• 1994

유사산 태아의 폐, 청색증을 나타내는 자돈으로부터 돼지생식기 및 호흡기증후군(PRRS)의 원인체로 추정되는 바이러스주(KPRRSV) 들을 분리하였다. 분리된 바이러스주는 돼지콜레라, 돼지오제스키병, 돼지뇌심근염바이러스에 대한 형광항체반응에서는 음성이었으며 기니픽혈구에 대한 혈구응집 능력을 나타내지 않았다. 그리고 포유 마우스의 뇌내 접종시 이상을 나타내지 않았으나 돼지생식기 및 호흡기증후군에 대한 형광항체검사시 양성반응을 나타내었다. 분리된 바이러스는 돼지폐포탐식세포(porcine alveola macrophages)에서 세포변성효과(cytopathic effect)를 나타내었으며 세포변성효과를 나타내었던 바이러스주중 일주(KPRRSV-1)를 돼지폐포탐식세포에서 7대 연속 계대하여 돼지에 접종한 후 혈청을 분리하여 미국 및 유럽지역에서 분리된 돼지유행성 유사산 및 호흡기증후군의 바이러스를 탐식세포에 감염시켜 효소면역방법 (immunoperoxidase monolayer assay)으로 분석한 결과 분리된 바이러스는 미국형 돼지호흡기 및 유사산증후군에 가까운 항원형으로서 판명되었다.

• 한국동물위생학회지
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• 제37권1호
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• pp.11-18
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• 2014

Porcine reproductive and respiratory syndrome (PRRS) causes a significant economic loss in the swine industry not only in Korea but also all over the world. Andong and Hapcheon region were selected for Area Regional Control (ARC) programme to reduce the shedding of PRRS virus (PRRSV) and decrease PRRS outbreaks. Before conducting the PRRS ARC, sera of pigs were tested for both antibody using ELISA and antigen using RT-PCR, then phylogenetic classifications was analysed. Pigs of 138/275 (50.2%) in Andong and 352/425 (82.8%) in Hapcheon were seropositive. Also, the RT-PCR results revealed that 27 heads (8.2%) in Andong, 112 heads (22.0%) in Hapcheon were positive for PRRSV antigen. PRRSVs were mainly detected between the ages of 40 to 60 days. PRRSV ORF5 regions were used to determine genetic clusters based on previous report. All PRRSV type I detected in both Andong and Hapcheon were classified as Cluster I. The PRRSV type II isolates in Andong were assorted to Cluster II, whereas the PRRSV type II isolates in Hapcheon were the viruses were unassembled into any cluster except one identified to Cluster III. Phylogenetic analysis indicated that new clusters of PRRSVs type II were prevalent in Hapcheon.

• 대한수의학회지
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• 제58권2호
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• pp.73-79
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• 2018

Outbreaks of porcine reproductive and respiratory syndrome virus (PRRSV) in vaccinated sow herds from occurrence to stabilization were monitored and analyzed in terms of serology and reproductive performance. Three different conventional pig farms experienced severe reproductive failures with the introduction of a type 1 PRRSV. These farms had adopted mass vaccination of sows using a type 2 PRRSV modified live vaccine (MLV). Therefore, to control the type 1 PRRSV, an alternative vaccination program utilizing both type 1 and type 2 MLV was undertaken. Following whole herd vaccinations with both types of MLV, successful stabilization of PRRS outbreaks was identified based on serological data (no viremia and downward trends in ELISA antibody titers in both sows and suckling piglets) and recovery of reproductive performance. Additionally, through comparison of the reproductive parameters between outbreak and non-outbreak periods, it was identified that PRRSV significantly affected the farrowing rate and the number of suckling piglets per litter at all three pig farms. Comparison of reproductive parameters between periods when the different vaccination strategies were applied revealed that the number of piglets born in total and born dead per litter were significantly increased after the introduction of the type 1 PRRS MLV.

• 한국동물위생학회지
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• 제45권1호
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• pp.63-69
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• 2022

Proliferative and necrotizing pneumonia (PNP) is a form of interstitial pneumonia that occurs in post-weaning pigs. In this study, we investigated the presence of swine influenza virus (SIV), porcine reproductive and respiratory syndrome virus (PRRSV), porcine circovirus type 2 (PCV2) and Aujeszky's disease virus (ADV) in PNP lesions in Jeju pigs. Based on the histopathologic criteria for PNP, a total of 50 cases were selected in Jeju pigs between 2008 and 2010. Coupled with histopathological examinations, the presence of ADV and SIV by polymerase chain reaction (PCR) and reverse transcription PCR (RT-PCR) and PRRSV and PCV2 by immunohistochemical (IHC) methods were investigated. Based on the PCR and RT-PCR methods, ADV and SIV nucleic acids were not detected in all cases. According to IHC, PRRSV was detected in 38 of the 50 cases examined (76%) and PCV2 in 25 cases (50%). PRRSV or PCV2 were detected in 19 (38%) or 6 (12%) cases, respectively. Both PRRSV and PCV2 were identified in other 19 cases (38%). Antigens of PRRSV and PCV2 were commonly observed in the cytoplasm of macrophages and clusters of necrotic cells in alveolar cavities. The results of the present study demonstrate that PRRSV is predominantly associated with PNP in Jeju pigs. Co-infection with PRRSV and PCV2 may enhance the severity of PNP lesions in affected pigs.

• 대한수의학회지
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• 제44권2호
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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.

• 한국동물위생학회지
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• 제38권1호
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• pp.1-7
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• 2015

This study was investigated to diagnose pathogenic organisms of atrophic piglets in northern area of the Gyeongnam province, Korea. Samples such as feces, blood and necropsy specimens of 42 atrophic piglets (${\leq}10$ weeks old) were taken from May to December 2013 for this survey. Samples were examined by reverse transcriptase-polymerase chain reaction (RT-PCR) assay and bacteria isolation for detection of pathogenic agents. 93 pathogens were isolated from 42 samples can be classified into ll groups. We identified bacterial agents in 56 cases (60.2%) and viral agents in 31 cases (33.3%). However, 6 cases (6.5%) were undetected. Among these pathogens, the most prevalent disease were porcine reproductive and respiratory syndrome (PRRS) in 22 cases (23.7%). The major diseases were Colibacillosis in 15 cases (16.1%), Glasser's disease in 12 cases (12.9%), and porcine epidemic disease (PED) in 9 cases (9.7%). Mixed infections were accounted for 77.8% of atrophic piglets. In particular, the rate of mixed infections with PRRS virus showed the highest frequency (71.4%). In addition, there is a seasonal variation. Viral pathogens were dominantly detected in winter, but in the rest of the season bacterial agents were mainly detected. Gastrointestinal diseases occurred mainly in the pre-weaning piglets, the respiratory diseases and wasting diseases occurred mainly in the post-weaning piglets.

• 대한수의학회지
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• 제46권4호
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• pp.363-370
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• 2006

Porcine reproductive and respiratory syndrome (PRRS) is an economically important disease of swine that occurs all over the swine industry worldwide. It was first observed in the Unite States in 1987 then in Europe in 1990. It has been described in Japan and in Korea in 1993. PRRS virus is divided into two distinct types, North American and European, genetically. Based on our limited knowledge there has been no report on the existence of European PRRSV. But according to the government's Korea Customs Service there has been many importations of breeding pigs from Europe. These seem to make an estimate that European PRRSV could be introduced in Korea by inflow of European breeding pigs. We first detected the European PRRSV could be introduced in Korean pig farms by using polymerase chain reaction (PCR). Further, it is also identified that there are not only North American PRRSV antibody but also a European PRRSV antibody. According to the genetical and serological experiment results, the presence of established North American PRRSV in Korea is due to the use of live vaccines made of North American PRRSV strain as well field virus infection, and the European PRRSV is possibly introduced from imported breeding stock.

• Asian-Australasian Journal of Animal Sciences
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• 제28권9호
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• pp.1354-1361
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• 2015

The complement system is a part of the natural immune regulation mechanism against invading pathogens. Complement activation from three different pathways (classical, lectin, and alternative) leads to the formation of C5-convertase, an enzyme for cleavage of C5 into C5a and C5b, followed by C6, C7, C8, and C9 in membrane attack complex. The C9 is the last complement component of the terminal lytic pathway, which plays an important role in lysis of the target cells depending on its self-polymerization to form transmembrane channels. To address the association of C9 with traits related to disease resistance, the complete porcine C9 cDNA was comparatively sequenced to detect single nucleotide polymorphisms (SNPs) in pigs of the breeds Hampshire (HS), Duroc (DU), Berlin miniature pig (BMP), German Landrace (LR), Pietrain (PIE), and Muong Khuong (Vietnamese potbelly pig). Genotyping was performed in 417 $F_2$ animals of a resource population (DUMI: $DU{\times}BMP$) that were vaccinated with Mycoplasma hyopneumoniae, Aujeszky diseases virus and porcine respiratory and reproductive syndrome virus at 6, 14 and 16 weeks of age, respectively. Two SNPs were detected within the third exon. One of them has an amino acid substitution. The European porcine breeds (LR and PIE) show higher allele frequency of these SNPs than Vietnamese porcine breed (MK). Association of the substitution SNP with hemolytic complement activity indicated statistically significant differences between genotypes in the classical pathway but not in the alternative pathway. The interactions between eight time points of measurement of complement activity before and after vaccinations and genotypes were significantly different. The difference in hemolytic complement activity in the both pathways depends on genotype, kind of vaccine, age and the interaction to the other complement components. These results promote the porcine C9 (pC9) as a candidate gene to improve general animal health in the future.

• 한국동물위생학회지
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• 제39권2호
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• pp.107-116
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• 2016

In the study, we developed and evaluated a uracil N-glycosylase (UNG)-supplemented single-tube nested reverse transcription-polymerase chain reaction (UsnRT-PCR) assay that can carried out first-round RT-PCR and second-round nested PCR in a reaction tube without reaction tube opening and can simultaneously detect EU- and NA-PRRSV. The UsnRT-PCR confirmed to have a preventing ability of mis-amplification by contamination of pre-amplified PRRSV DNA from previous UsnRT-PCR. Primer specificities were evaluated with RNAs extracted from 8 viral strains and our results revealed that the primers had a high specificity for both genotypes of PRRSV. The sensitivity of the UsnRT-PCR was 0.1 $TCID_{50}$/0.1 mL for EU- or NA-PRRSV, respectively, which is comparable to that of previously reported real time RT-PCR (RRT-PCR). Clinical evaluation on 110 field samples (60 sera and 50 lung tissues) by the UsnRT-PCR and the RRT-PCR showed that detection rates of the UsnRT-PCR was 70% (77/110), and was relatively higher than that of the RRT-PCR (69.1%, 76/110). The percent positive or negative agreement of the UsnRT-PCR compared to RRT-PCR was 96.1% (73/76) or 90.9% (30/33), showing that the test results of both assays may be different for some clinical samples. Therefore, it is recommend that diagnostic laboratory workers use the two diagnostic assays for the correct diagnosis for the relevant samples in the swine disease diagnostic laboratories. In conclusion, the UsnRT-PCR assay can be applied for the rapid, and reliable diagnosis of PRRSV without concerns about preamplified DNA carryover contamination that can occurred in PCR process in the swine disease diagnostic laboratories.