• Journal of Veterinary Science
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• 제25권2호
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• pp.28.1-28.11
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• 2024

Background: Porcine circovirus type 2 (PCV2) infection is ubiquitous around the world. Diagnosis of the porcine circovirus-associated disease requires clinic-pathological elements together with the quantification of viral loads. Furthermore, given pig farms in regions lacking access to sufficient laboratory equipment, developing diagnostic devices with high accuracy, accessibility, and affordability is a necessity. Objectives: This study aims to investigate two newly developed diagnostic tools that may satisfy these criteria. Methods: We collected 250 specimens, including 170 PCV2-positive and 80 PCV2-negative samples. The standard diagnosis and cycle threshold (Ct) values were determined by quantitative polymerase chain reaction (qPCR). Then, two point-of-care (POC) diagnostic platforms, convective polymerase chain reaction (cPCR, qualitative assay: positive or negative results are shown) and EZtargex (quantitative assay: Ct values are shown), were examined and analyzed. Results: The sensitivity and specificity of cPCR were 88.23% and 100%, respectively; the sensitivity and specificity of EZtargex were 87.65% and 100%, respectively. These assays also showed excellent concordance compared with the qPCR assay (κ = 0.828 for cPCR and κ = 0.820 for EZtargex). The statistical analysis showed a great diagnostic power of the EZtargex assay to discriminate between samples with different levels of positivity. Conclusions: The two point-of-care diagnostic platforms are accurate, rapid, convenient and require little training for PCV2 diagnosis. These POC platforms can discriminate viral loads to predict the clinical status of the animals. The current study provided evidence that these diagnostics were applicable with high sensitivity and specificity in the diagnosis of PCV2 infection in the field.

• 한국동물위생학회지
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• 제41권3호
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• pp.133-139
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• 2018

Porcine circovirus type 2 (PCV2) and porcine reproductive and respiratory syndrome virus (PRRSV) are known as significant immunosuppressive viruses in pigs. In this study, we investigated the correlation of PCV2 and PRRSV in enteric lesions of porcine salmonellosis. A total of 64 cases were classified into four pig groups as group A (24 cases, S. Typhimurium), group B (11 cases, S. Typhimurium+PCV2), group C (16 cases, S. Typhimurium+PRRSV) and group D (13 cases, S. Typhimurium+PCV2+PRRSV). Comparing with group A, ulcerative enteritis in large intestine was little more prevalent in the PCV2 infected pigs in group B and D. And lymphoid depletion in gut-associated lymphatic tissue (GALT) of large intestine was also detected in PCV2 positive group B (36.4%) and D (30.8%). According to the results of immunohistochemistry (IHC), PCV2 antigens (83.3%) were more prevalently distributed in the intestinal lesions of porcine salmonellosis than PRRSV antigens (10.3%). PCV2 were also detected in the lymphoid depleted GALT of the large intestine from 7 of the 8 pigs (87.5%), but PRRSV were not found in all cases. It may explain that PCV2 can play a certain immunological role to enhance secondary bacterial infection in porcine alimentary tracts.

• 대한수의학회지
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• 제53권4호
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• pp.245-251
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• 2013

Porcine circovirus type 2 (PCV2) and porcine reproductive and respiratory syndrome virus (PRRSV) have been suspected to have immunosuppressive effects on pigs. To investigate the correlation between these virus infection and the lesions of lymph nodes including sub-mandibular and inguinal lymph node, 44 pigs (PCV2 single, n = 14; PRRSV single, n = 10; PCV2/PRRSV, n = 14; negative control, n = 6) were examined by histopathology and immunohistochemistry. Histopathologically, granulomatous lymphadenitis characterized by lymphoid depletion with histiocytic cells infiltration was observed in PCV-2 single and PCV-2/PRRSV group. Immunohistochemically, there were significant reduction of B and T lymphocytes in lymph nodes of these groups, while the number of macrophages was increased. In only PRRSV infected group, germinal center hypertrophy and lymphoid necrosis were observed. Immunohistochemically, the number of CD3+ T lymphocytes was slightly increased. Severe lymphocytic depletion in PCV-2 infection-related lymph nodes might be associated with producing immunocompromised state in pig. Comparing with PCV-2 infected group, PRRSV produced minor effects on the changes in immune cell population in the lymph nodes of pigs. PRRSV may increase susceptibility of the disease in pigs by disruption of the first defense lines in target organs, such as the alveolar macrophages in lungs.

• 한국동물위생학회지
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• 제34권1호
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• pp.1-4
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• 2011

A surface plasmon resonance imaging (SPRI) assay was developed for measuring porcine circovirus type 2 (PCV2) antibody using a recombinant capsid protein as an antigen. The diagnostic potential of SPRI for detecting antibodies to the PCV2 capsid protein was compared with that of a conventional enzyme-linked immunosorbent assay (ELISA) using 70 pig serum samples taken from 6 pig farms. There was a strong positive correlation between the SPRI and ELISA (n = 70, r = 0.911, P<0.01). Therefore, this recombinant capsid protein can be used as an antigen for serological studies, and the SPRI, a label-free and high-throughput method, is expected to be a valuable tool in the serodiagnosis of PCV2 infection.

• 대한수의학회지
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• 제60권3호
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• pp.155-161
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• 2020

From 2006 to 2009, 50 pigs suspected of enteritis associated with porcine circovirus type 2 (PCV-2) (EAPC) were collected. Gross and histopathologic examinations and immunohistochemistry (IHC) were performed on the small intestine of 50 pigs. The pigs with EAPC were concentrated in grower pigs (68%), and diarrhea (84%) was the most common clinical sign. Grossly, the walls of the small intestine were thickened, and mesenteric lymph nodes were enlarged. The histopathologic features in the small intestine with EAPC were characterized by lymphoid depletion, histiocytic infiltration, and formation of basophilic grape-like inclusion bodies and multinucleated giant cells in gut-associated lymphatic tissue (GALT) and lamina propria. According to IHC, PCV-2 antigens were more intense and distributed widely in GALT (98%) than lamina propria (82%) of the small intestine. Co-infection with other enteric pathogens was detected in 26 pigs (52%). Twenty-four pigs (48%) were confirmed to be a PCV-2 single infection. Collectively, infected PCV-2 in the small intestine may induce an immunosuppressive status of individuals and then allow secondary co-infections in the digestive system. This study shows that PCV-2 can induce diarrhea and enteric lesions in pigs without a co-infection of other enteric pathogens.

• Journal of Preventive Veterinary Medicine
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• 제41권3호
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• pp.129-132
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• 2017

The current study identified risk factors associated with porcine circovirus type 2 (PCV2) infection on pig farms in the Republic of Korea using a multinomial logistic regression model to evaluate the PCV2 infection status of pigs at different growth stages. Compulsory disinfection of visitors (odds ratio [OR]: 0.019, 95% confidence interval [CI]: <0.001-0.378, p=0.0095), compulsory registration of visitors (OR: 0.002, 95% CI: <0.001-0.184, p=0.0070), regular blood testing (OR: 0.012, 95% CI: <0.001-0.157, p=0.0007), and running on-farm biosecurity learning programs for workers (OR: 0.156, 95% CI: 0.040-0.604, p=0.0072 and OR: 0.201, 95% CI: 0.055-0.737, p=0.0155, respectively) were identified as factors which could reduce the risk of PCV2 infection. However, visitation by a regular veterinarian (OR: 32.733, 95% CI: 3.768-284.327, p=0.0016) was associated with PCV2 infection.

• 한국임상수의학회지
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• 제27권6호
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• pp.704-712
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• 2010

Porcine circovirus-2 (PCV2) 는 돼지에서 여러 형태의 질병과 증후군의 발생과 관련이 되어있어 현재는 PCV-associated diseases (PCVAD)로 총괄적으로 분류된다. PCVAD에 의한 높은 경제적 손실 때문에 많은 양돈장들이 PCV2의 감염을 확인하기 위하여 혈청을 검사하고 있다. 하지만, 기존의 혈액채취법은 비용이 높고 많은 인력이 소요되므로 큰 규모의 병원체 검사에는 어려움이 있었다. 이에 본 연구에서는 혈액채취법을 이용한 돈군의 PCV2 검사법에 대한 대체방법으로 돈방 단위의 구강액채취법의 유용성을 실제 농장에서 평가하였다. 세 곳의 다른 양돈 농장들에서 각각 6개의 25두 규모의 돈방들을 선정하여 생후 3, 5, 8, 12, 16주에 돈방 마다 하나의 구강액과 5개의 혈청을 채취하였다. 모든 시료들은 real-time PCR을 이용하여 PCV2 DNA를 검사하였고 IgG 또는 IgA 간접형광항체 검사법및 세 가지의 ELISA 검사법 (blocking ELISA, indirect ELISA, and IgG/IgM sandwich ELISA)을 이용하여 PCV2에 대한 항체를 검사하였다. 구강액에서 PCV2 DNA는 8주까지는 간헐적으로 검출이 되다가 16주에는 모든 돈방에서 검출이 되었으며, 모체유래 PCV2 특이 IgG는 3주부터 검출이 되었고 모든 농장에서 5-8주까지 지속이 되었다. 16주에는 한 농장 (Site 1)의 모든 돈방에서 감염에 의한 IgG와 IgA가 검출되었다. 혈청에서의 PCV2 DNA와 PCV2 항체의 검출은 구강액에서의 검출과 높은 상관관계를 보였다. 따라서 구강액은 돈군의 PCV2 감염을 모니터링 하기 위해 혈청대신 사용할 수 있는 저비용, 고효율의 시료가 될 수 있을 것으로 사료된다.

• Journal of Animal Science and Technology
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• 제63권6호
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• pp.1223-1231
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• 2021

Regulator of G protein signaling 16 (RGS16) is known to be associated with porcine circovirus type 2 (PCV2). PCV2 associated disease (PCVAD) is a serious problem in the swine industry. The representative symptoms of PCVAD are high viral titer proliferation and decreased average daily gain. In this study, we identified single nucleotide polymorphisms (SNPs) in the RGS16 region, including the upstream region. Of the 22 identified SNPs, rs332913874, rs326071195, and rs318298586 were genotyped in 142 Yorkshire pigs. These SNPs were significantly associated with the PCV2 viral load. Moreover, the haplotype combination was also related to the PCV2 viral load. The haplotype and diplotype analysis also had a significant difference with the PCV2 viral load. Taken together, our results suggest that RGS16 SNPs considerably affect the PCV2 viral load.

• International Journal of Industrial Entomology and Biomaterials
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• 제30권2호
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• pp.50-57
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• 2015

Porcine circovirus type 2 (PCV2) is an important infectious swine virus causing postweaning multisystemic wasting syndrome (PMWS). PCV2 capsid protein, encoded by ORF2 has type-specific epitopes, is very immunogenic, and is associated with the induction of neutralizing antibodies. For the efficient production of capsid protein, recombinant Autographa californica nucleopolyhedroviruses were generated to express ORF2 fused with two forms of a partial polyhedrin. Recombinant capsid protein was produced successfully with the partial polyhedrin fusion form and the yield was high, as was shown by SDS-PAGE. Production of recombinant capsid proteins in insect cells was confirmed by Western blot analysis using anti-His monoclonal antibody, anti-ORF2 monoclonal antibody, and anti-PCV2 porcine serum. Fusion expression with amino acids 19 to 110 of the polyhedrin increased the production of recombinant capsid protein, but fusion with amino acids 32 to 85 did not. Additionally, PCV2 capsid protein is a glycoprotein; however, the glycosylation of recombinant protein was not observed. The results of an Enzyme-linked immunosorbent assay (ELISA) showed that recombinant capsid proteins could be utilized as antigens for fast, large-scale diagnosis of PCV2-infected pigs. Our results suggest that the fusion expression of partial polyhedrin is able to increase the production of recombinant PCV2 capsid protein in insect cells.

• 한국동물위생학회지
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• 제29권3호
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• pp.249-256
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• 2006

Porcine circovius type 2 (PCV 2) is a novel virus of Circoviridae familiy which is considering the cause of postweaning multisystemic wasting syndrome (PMWS). This study was carried out to investigate the prevalence of PCV 2 infection of swine in eastern areas of Gangwon province from February to June in 2005. Polymerase chain reaction (PCR) were conducted to identify the PCV 2 genome against 80 pigs. The number of infection and its rate of 4 areas, 8 farms and 80 pigs were 3 (75.0%), 7 (88.0%) and 44 (55.0%), respectively.