• Journal of The Korean Society of Agricultural Engineers
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• v.54 no.1
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• pp.63-72
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• 2012

In livestock industry, damage caused by the epidemic diseases such as Foot-and-Mouth Disease (FMD), Highly-Pathogenic-Avian-Influenza (HPAI) and Porcine-Reproductive-and-Respiratory-Syndrome (PRRS) was very serious. The financial loss incurred from FMD alone which occurred on Nov. 2011 in Korea was estimated at 3 billion won, 23 % of annual livestock industry production. The livestock industry in Korea has greater risk of disease infection because of high density production, etc. Investigating the spread of livestock diseases should consider both direct and indirect contact as well as other various factors including airborne. Airborne infection of livestock disease was first hypothesised in the early 1900s, however, field experimental studies are still limited. Furthermore, no protocol is available in detecting airborne viruses in the field. In this study, effective virus samplers were investigated by comparative analysis of the type of samplers used detect to airborne virus. Laboratory experiments were conducted to compare virus samplers such as Bio-sampler, Dust-sampler, Compact-Cascade-Impactor (CCI) and Microflow in detecting PRRSV. Samples were analyzed by Reverse-Transcription PCR to assess the efficiency of the instrument in detecting the airborne virus. First, samples were classified into five levels according to light intensity of gel images and then the classified results were normalized. In every case, Bio-sampler and Dust-sampler were comparable with each other and have shown to be more effective than CCI and Microflow samplers.

• Journal of Veterinary Science
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• v.24 no.1
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• pp.11.1-11.14
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• 2023

Background: Peripheral blood mononuclear cells (PBMCs) are commonly used to assess in vitro immune responses. However, PBMC isolation is a time-consuming procedure, introduces technical variability, and requires a relatively large volume of blood. By contrast, whole blood assay (WBA) is faster, cheaper, maintains more physiological conditions, and requires less sample volume, laboratory training, and equipment. Objectives: Herein, this study aimed to develop a porcine WBA for in vitro evaluation of immune responses. Methods: Heparinized whole blood (WB) was diluted (non-diluted, 1/2, 1/8, and 1/16) in RPMI-1640 media, followed by phorbol myristate acetate and ionomycin. After 24 h, cells were stained for interferon (IFN)-γ secreting T-cells followed by flow cytometry, and the supernatant was analyzed for tumor necrosis factor (TNF)-α. In addition, diluted WB was stimulated by lipopolysaccharide (LPS) and polyinosinic:polycytidylic acid (poly I:C), reference strain KCTC3557 (RS), field isolate (FI), of heat-killed (HK) Streptococcus suis, and porcine reproductive and respiratory syndrome virus (PRRSV). Results: The frequency of IFN-γ⁺CD3⁺ T-cells and concentration of TNF-α in the supernatant of WB increased with increasing dilution factor and were optimal at 1/8. WB TNF-α and interleukin (IL)-10 cytokine levels increased significantly following stimulation with LPS or poly I:C. Further, FI and RS induced IL-10 production in WB. Additionally, PRRSV strains increased the frequency of IFN-γ⁺ CD4^-CD8⁺ cells, and IFN-γ was non-significantly induced in the supernatant of re-stimulated samples. Conclusions: We propose that the WBA is a rapid, reliable, and simple method to evaluate immune responses and WB should be diluted to trigger immune cells.

• Korean Journal of Veterinary Research
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• v.44 no.2
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• pp.279-286
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• 2004

Total 160 head of porcine kidneys were examined for gross and histopathological lesions and polymerase chain reaction (PCR) for porcine circovirus type 2 (PCV-2), porcine parvovirus (PPV), Leptospira species and porcine reproductive and respiratory syndrome virus (PRRSV). Grossly, 137 kidneys (85.6%) had lesions characterized by the presence of the scattered white foci. Microscopically, multifocal interstitial nephritis, which classified into 4 grades such as, no lesion (Score 0), mild lesion (Score 1), moderate lesion (Score 2) and severe chronic lesion (Score 3) with fibrosis, was observed in 159 cases (99.4%). The histopathologic mean score for multifocal interstitial nephritis was significantly different (P<0.05) between the cases of PCV-2 single infection and the cases of co-infection with PCV-2 and PPV. According to PCR evaluation, PCV-2 were detected in 73.8% (118 cases), PPV were in 66.9% (107 cases), however Leptospira spp. and PRRSV were negative in all kidneys. Both PCV-2 and PPV were detected in 52.5% (84 cases). In 84 cases co-infected with PCV-2 and PPV, the occurrence of lymphoid follicle and vasculitis were observed as 65.5% (55 cases) and 26.2% (22 cases), respectively. These results revealed that PCV-2 and PPV were major infectious agents for interstitial nephritis in slaughtered pigs, Jeju. And the histopathologic lesions of multifocal interstitial nephritis were more severe in the case co-infected with PCV-2 and PPV.

• Korean Journal of Veterinary Service
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• v.39 no.4
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• pp.231-237
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• 2016

The present study was conducted to investigate the lesion of red internal organs in slaughtered pigs and provided assistant data for pig farms. During March to December 2015, a total of 1,160 lung samples out of 58 herds were collected randomly from pigs slaughtered in Jeonbuk province. In addition, 290 hilar lymph nodes from pig with pneumonic lung lesion (5 samples per herd) were screened for selected viral and bacterial pathogens. Gross lesions of lungs such as swine enzootic pneumonia (SEP), pleuritis, pleuropneumonia, pericarditis and liver white spots were examined. The overall prevalence of SEP was 64.3% (746/1,160). In the analysis of seasonal prevalence, there was an increase of occurrence during the spring months (287/400, 71.8%) and decrease during the fall months (93/200, 46.5%) among the whole herds. The mean number of SEP score per pig was $1.20{\pm}1.28$. The prevalence of pleuropneumonia, pleuritis, pericarditis, and milk spot was 25.5% (296/1,160), 44.1% (512/1,160), 3.8% (44/1,160) and 17.6% (204/1,160), respectively. The most frequent region with lung lesion was diaphragmatic lobes (left 17.1%, right 17.3%). In the detection of viral pathogens by PCR, porcine circovirus type2 (PCV2) was positive in 86.9% (252/290), while porcine reproductive and respiratory syndrome virus (PRRSV) was not detected, In the case of bacterial pathogens, 50 microorganisms were isolated by PCR and/or microbiological test. The most frequently isolated bacteria was Streptococcus suis (20, 34.4%), followed by Pasteurella multocida (17, 29.3%), Streptococcus spp. (11, 3.4%), Actinobacillus pleuropneumoniae (2, 8.9%).

• Korean Journal of Veterinary Service
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• v.38 no.1
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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.

• Korean Journal of Veterinary Research
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• v.38 no.2
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• pp.314-318
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• 1998

An establishment of effective control measures to PRRSV infection in swine industry depends on a sensitive and specific diagnosis to detect either viral antigen and/or antibodies to PRRSV. Several diagnostic methods are available to detect antibodies against PRRSV, including IPMA, IFA and ELISA tests have been successfully developed. Sensitivity of the indirect immunofluorescent assay in MA-104 cells using Korean field isolate PL96-1 was superior to that of VR-2332 and field isolate PL96-2. Sensitivity and specificity of the IFA test with PL96-1 were comparable to those of commercial ELISA test kit but ELISA test was more sensitive for the detection of declining antibodies to PRRSV in finishing pigs. In this study we concluded that IFA and ELISA test could be utilized to detect antibodies to PRRSV and the results generated from these two tests were comparable and there were no significant difference between these two tests.

• Korean Journal of Veterinary Research
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• v.47 no.2
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• pp.175-185
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• 2007

This study was carried out to investigate the pathogenesis and pathogenicity of the porcine circovirus type 2 (PCV2) Korean isolate from weaned pigs. Twenty four weaned pigs, PCV2, porcine reproductive and respiratory syndrome virus (PRRSV) and porcine parvovirus (PPV) antibodies free, were allocated to 4 groups (n = 6). Six pigs were inoculated intranasally with PCV2 alone, 6 with PCV2 and PRRSV, 6 with the combined PCV2/PRRSV/PPV inoculum, and 6 were remained as a uninoculated negative control. Pigs were killed 3 and 6 weeks after inoculation and tissue samples examined for gross and microscopic lesions and for the presence of PCV2 antigens and nucleic acids. Experimentally inoculated pigs were evaluated for 3 considerations: 1. development of postweaning multisystemic wasting syndrome (PMWS), 2. distribution of viral antigens by immunohistochemistry and polymerase chain reaction (PCR), and 3. cytokine mRNA levels in lymph nodes. Pigs inoculated with PCV2/PRRSV/PPV showed typical clinical signs, gross findings, and histopathologic characteristics of PMWS. In the PCV2/PRRSV/PPV inoculated group, the PCV2 antigen was widely distributed in various parenchymal organs such as brain, spinal cord, tonsil, lymph nodes, lung, heart, liver, kidney, spleen, and peyer's patch. Lymph node mRNA expression of IL-$1{\alpha}$, IL-2R and IL-8 was determined by real-time PCR. The pigs of PCV2/PRRSV and PCV2/PRRSV/PPV inoculation group, the mRNA expression was characterized by a decrease of IL-$1{\alpha}$, IL-2R and IL-8. The decrease of cytokine mRNA represent the state of T cell immuno-suppression in pig, and nicely support the evidence for the impairment of immune system in pigs with PMWS. In conclusion, PCV2 infection and some additional infectious causes such as PRRSV and/or PPV are warranted for the presence of PMWS in weaned pigs in Korea.

• Korean Journal of Veterinary Research
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• v.48 no.3
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• pp.267-274
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• 2008

This study was to evaluate the efficacy of single dose Mycoplasma hyopneumoniae (M. hyo)-vaccination in the swine farms which had different serological patterns of porcine reproductive and respiratory syndrome virus (PRRSV) and porcine circovirus type 2 (PCV2). A minimum of 240 pigs from each farm was applied, allocating M. hyo vaccinated and control groups. The PRRSV and PCV2 infections were analyzed by serological method (commercial ELISA kit). After administrating pigs a single dose of M. hyo vaccine or control saline at 3 weeks of age, serum antibodies to M. hyo, PRRSV and PCV2 were monitored at 4, 10, 16 and 22 weeks of age. Mortality, weight changes, feed conversion ratio (FCR) and lung score were also evaluated. A single-dose vaccination of M. hyo bacterin was efficacious to reduce mycoplasmal lung lesions and induce good humoral immune response. However, FCR was improved only in one of the three farms where showed seronegative status to both PRRSV and PCV2 in the period from 4 to 16 weeks of age. These results might imply that M. hyo vaccine alone could not overcome the PRRSV and PCV2 infection-associated wasting in the field condition. Therefore, the control of PRRSV and PCV2 should be considered to obtain the better effects of M. hyo vaccination.

• Animal Bioscience
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• v.35 no.6
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• pp.791-803
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• 2022

Genome/gene-editing (GE) techniques, characterized by a low technological barrier, high efficiency, and broad application among organisms, are now being employed not only in medical science but also in agriculture/veterinary science. Different engineered CRISPR/Cas9s have been identified to expand the application of this technology. In pig production, GE is a precise new breeding technology (NBT), and promising outcomes in improving economic traits, such as growth, lean or healthy meat production, animal welfare, and disease resistance, have already been documented and reviewed. These promising achievements in porcine gene editing, including the Myostatin gene knockout (KO) in indigenous breeds to improve lean meat production, the uncoupling protein 1 (UCP1) gene knock-in to enhance piglet thermogenesis and survival under cold stress, the generation of GGTA1 and CMP-N-glycolylneuraminic acid hydroxylase (CMAH) gene double KO (dKO) pigs to produce healthy red meat, and the KO or deletion of exon 7 of the CD163 gene to confer resistance to porcine reproductive and respiratory syndrome virus infection, are described in the present article. Other related approaches for such purposes are also discussed. The current trend of global regulations or legislation for GE organisms is that they are exempted from classification as genetically modified organisms (GMOs) if no exogenes are integrated into the genome, according to product-based and not process-based methods. Moreover, an updated case study in the EU showed that current GMO legislation is not fit for purpose in term of NBTs, which contribute to the objectives of the EU's Green Deal and biodiversity strategies and even meet the United Nations' sustainable development goals for a more resilient and sustainable agri-food system. The GE pigs generated via NBT will be exempted from classification as GMOs, and their global valorization and commercialization can be foreseen.

• Korean Journal of Veterinary Service
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• v.39 no.1
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• pp.41-49
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• 2016

In the present study, fast and robust methods for the next generation sequencing (NGS) were developed for analysis of PRRSV full genome sequences, which is a positive sensed RNA virus with a high degree of genetic variability among isolates. Two strains of PRRSVs (VR2332 and VR2332-R) which have been maintained in our laboratory were used to validate our methods and to compare with the sequence registered in GenBank (GenBank accession no. EF536003). The results suggested that both of strains had 100% coverage with the reference; the VR2332 had the coverage depth from minimum 3 to maximum 23,012, for the VR2332-R from minimum 3 to maximum 41,348, and 22,712 as an average depth. Genomic data produced from the massive sequencing capacities of the NGS have enabled the study of PRRSV at an unprecedented rate and details. Unlike conventional sequence methods which require the knowledge of conserved regions, the NGS allows de novo assembly of the full viral genomes. Therefore, our results suggested that these methods using the NGS massively facilitate the generation of more full genome PRRSV sequences locally as well as nationally in regard of saving time and cost.