• Korean Journal of Veterinary Research
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• v.39 no.2
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• pp.311-317
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• 1999

Pathogenic effects of 29 different porcine reproductive and respiratory syndrome(PRRS) virus isolates were investigated in swine tracheal ring(STR) cultures by examining their effects on the ciliary activity of STR. Inhibition of ciliary movement and destruction of the tracheal epithelium were seen between 72 and 96 hours postinoculation(PI). Virus replication was demonstrated by examining viral infectivity of the supernatants from the STR cultures. PRRS virus antigen in macrophages was detected by a streptavidin-biotin complex(ABC) immunoperoxidase method. Of the 29 PRRS virus isolates, 8 isolates were classified into pathogenic, and the remaining 21 isolates were determined as mildly pathogenic or apathogenic viruses. These results suggest that STR examination may be used as a method for predicting pathogenic variability of PRRS virus isolates.

• Korean Journal of Veterinary Research
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• v.34 no.1
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• pp.77-83
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• 1994

Three viral strains, causing CPE in porcine alveolar macrophage cell, were isolated from aborted fetus, serum from young pig showing blue-ear sign and lung of suspected pig, respectively. The differential diagnostic results showed no characteristics of Aujeszky's disease virus(ADV), hog cholera virus (HCV), Japanese encephalitis virus(JEV), porcine parvovirus(PPV) and encephalomyocarditis virus (EMCV). However, positive reactions were demonstrated by IFA using monospecific porcine antibodies against Lelystad virus. When the paired sera of experimentally inoculated swine with one of isolate, KPRRSV-l were tested by IPMA, the result indicated that the isolate was related to United States isolate than European LV.

• 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 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 Research
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• v.37 no.4
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• pp.765-772
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• 1997

제주지역 돼지에서 각종 전염성 질병 원인체에 대한 항체를 조사하여 그간 전염성 병원체에 대한 역학조사가 미진하였던 부분을 보완하여 질병의 분포를 파악하고자 1995년부터 1996년에 걸쳐 제주도 전역에서 돼지의 혈청을 채취하여 각종 병원체에 대한 항체 분포율을 조사하였다. 본 연구에서 검사한 돼지 혈청 시료에서는 돼지 오제스키병 바이러스에 대한 항체는 전혀 검출되지 않았다. 돼지 콜레라바이러스에 대한 항체는 기대 수준 이하로 낮아 백신접종이 원활히 수행되고 있지 않음을 시사하였으며 특히 농장에 따라 항체 보유돈과 항체 음성돈이 혼재하는 농장과 항체가 전혀 검출되지 않는 농장 등 돼지 콜레라 방역의 사각지대가 존재할 가능성이 있음을 보여주었다. 유 사산 원인체인 돼지 파보바이러스 및 뇌심근염에 대한 항체가가 다양하게 나타나 일부 문제가 있을 것으로 사료되었다. 돼지 생식기호흡기증후군(PRRS) 바이러스에 대한 항체 분포율은 내륙 보다 다소 낮게 나타났고, 돼지 influenza virus, 위축성 비염, 흉막 폐염 등 각종 세균성 질환에 대한 항체수준도 다양하게 나타났다. 본 혈청학적인 연구결과는 제주지역에서의 양돈방역 정책수립 및 질병방제의 기초자료로 유용하게 이용될 것으로 사료된다.

• Korean Journal of Veterinary Service
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• v.24 no.4
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• pp.359-367
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• 2001

A serological survey was performed to establish basic data for the prevalence of antibodies to some major diseases of domesticated boar serum samples from January to December 2000. Sera collected in breeding farms in Gyeongbuk province were tested for Aujeszky's disease virus(ADV), Porcine reproductive and respiratory syndrome virus(PRRSV), Porcine parvovirus(PPV), Japanese encephalitis virus (JEV), Bordetella bronchiseptica(B bronchiseptica), Mycoplasma ; APP), Toxoplasma, and Brucella. There was no antibody to ADV in domesticated boars serum samples detected by Anti-ADV-gpI assay kit. Sero-positive samples to PRRS by IFA were 0.9%(3/330) The HI titers to PPV ranged variously from less than 10 to over 1,280. Two hundred ninety-four out of 330 tested sera showed HI titer of less than 10. In HI test to JEV, 90.3% of the sera (298/330) were below 10. The majority of the serum samples had low prevalence of the antibody B bronchiseptica. ELISA titers to M hyopneumoniae ranged variously from $\leq$ 10 to $\geq$ 1,280. Antibody titers to A pleuropneumoniae type 2(APP2) and type 5(APP5) were 58.2% and 52.7%, respectively, and the tested samples showing ELISA antibody titers of less than 20. There was no significant geographical difference between APP2 and APP5 in this study. In the antibody test of Toxoplasma, 11.5%(38/330) were positive and samples were all negative in sera test of Brucella.

• Korean Journal of Veterinary Service
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• v.43 no.1
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• pp.39-44
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• 2020

The aim of this study is to investigate how the gut microbiome shifts when pigs were exposed with low concentrations of mycotoxins, deoxynivalenol (DON) and zearalenone (ZEN) in feed. Fifteen of pigs, 15 kg in weight which were negative for PRRSV and PCV2 were purchased, acclimatized until 20 kg in weight, and randomly divided into 3 groups; the DON group (DON treated), the ZEN group (ZEN treated) and the CTL (untreated negative control). DON and ZEN administered to each group for 30 days at 0.8 mg/kg (800 ppb) and 0.20 mg/kg (200 ppb) in feed, respectively. After extraction of microbial DNA from intestine and fecal samples, sequencing procedures were performed in the Ion PGM using an Ion 316 V2 chip and Ion PGM sequencing 400 kit. The results suggested that the bacterial communities in duodenum, jejunum and ileum of the DON and ZEN groups presented low-abundant OTUs compared with the CTL group. OTUs in cecum, colon and feces were determined more than in small intestine of all three groups. However, the CTL group yielded more OTUs than other two groups in inter-group comparison. It is not fully clarified how the richness and abundance in microbiome functions in the health condition of animals, however, the exposure to DON and ZEN has caused microbial population shifts representing microbial succession and changes following the diversity and abundance of porcine gut microbiome. The metabolomic analysis correlate with microbiome analysis is needed for further study.

• Korean Journal of Veterinary Research
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• v.57 no.2
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• pp.143-146
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• 2017

Porcine ear necrosis syndrome is characterized by erosive and ulcerative lesions at the margin or tip of the pinna. Three growing pigs of different ages exhibited retarded growth accompanied by reddening and necrosis of ear prior to death. Gross examination showed reddening, swelling, black discoloration, scaling, and variable-sized yellowish materials and edema in ear cross section. Microscopically, thrombosis, abscess, ulceration, epidermal hyperplasia, and dermal pyogranulomatous inflammation with an intralesional bacterial colony were observed. Staphylococcus hyicus was isolated in all pigs' ears and porcine reproductive and respiratory syndrome virus was detected by PCR and immunohistochemistry.

• Korean Journal of Veterinary Research
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• v.39 no.4
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• pp.751-759
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• 1999

Plaque characteristics of porcine reproductive and respiratory syndrome (PRRS) virus isolates were examined using MARC-145 line cells. The plaque morphology of PRRS virus isolates was variable in size and heterogenic in population. Upon serial passages of the PRRS virus isolates on MARC-145 tells, heterogeneity was maintained but numbers of the large plaque size virus were increased with certain isolates. A PRRS virus isolate with variable plaque sizes was subcloned into 2 populations : small plaque ($H_S$) and large plaque ($H_L$) viruses. Growth kinetics of the subclones were then determined in MARC-145 cells, and production of the structural polypeptides was analyzed by SDS-PAGE. In a comparison of the growth kinetics, the $H_S$ virus showed higher infectivity titers during the first 48 hours but slower to reach the peak titier than $H_L$ virus did. In a nucleotide sequence comparison, differences of 4 nucleotides in open reading frames 5-6 gene were found between $H_S$ and $H_L$ viruses. Both the $H_S$ and $H_L$ clones produced 5 polypeptide bands with molecular weights of 15, 19, 26, 36 and 42 kD. The 5 bands were detected at 48 hours postinoculation (PI) with antisera to $H_L$ and another large plaque virus ($W_L$) and at 72 hours PI with $H_S$ virus antiserum. The present results demonstrate differences of biologic and molecular characteristics between the two PRRS virus plaque clones.

• 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.