• Korean Journal of Veterinary Service
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• v.26 no.3
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• pp.227-231
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• 2003

The purpose of this study was sero-epidemiological survey of porcine reproductive and respiratory syndrom(PRRS) in Dangjin area. 411 samples from 26 pig farms were analyzed by enzyme linked immunosorbant assay (ELISA). The data indicate that 66% of the pigs and 92% of the farms showed sero-positives to the PRRS viruc. Sows showed 58% of sero-positive rate and fattening pigs showed 85% of seropositive rate. The rate of sero-positive in boars was 63%. No significant regional differences were detected in sero-epidemiological survey.

• Molecules and Cells
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• v.23 no.1
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• pp.1-10
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• 2007

Invading pathogens are recognized by diverse germline-encoded pattern-recognition receptors (PRRs) which are distributed in three different cellular compartments: extracellular, membrane, and cytoplasmic. In mammals, the major extracellular PRRs such as complements may first encounter the invading pathogens and opsonize them for clearance by phagocytosis which is mediated by membrane-associated phagocytic receptors including complement receptors. The major membrane-associated PRRs, Toll-like receptors, recognize diverse pathogens and generate inflammatory signals to coordinate innate immune responses and shape adaptive immune responses. Furthemore, certain membrane-associated PRRs such as Dectin-1 can mediate phagocytosis and also induce inflammatory response. When these more forefront detection systems are avoided by the pathogens, cytoplasmic PRRs may play major roles. Cytoplasmic caspase-recruiting domain (CARD) helicases such as retinoic acid-inducible protein I (RIG-I)/melanoma differentiation-associated gene 5 (MDA5), mediate antiviral immunity by inducing the production of type I interferons. Certain members of nucleotide-binding oligomerization domain (NOD)-like receptors such as NALP3 present in the cytosol form inflammasomes to induce inflammatory responses upon ligand recognition. Thus, diverse families of PRRs coordinately mediate immune responses against diverse types of pathogens.

• Korean Journal of Veterinary Research
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• v.43 no.1
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• pp.129-137
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• 2003

Porcine reproductive and respiratory syndrome (PRRS) is characterized by reproductive failures in sows and respiratory problems in piglets. The nucleocapsid(N) protein, encoded by the open reading frame 7 (ORF7) gene, is known to be the most abundant and antigenic protein in PRRS virus. Therefore, it was suggested that the N protein could be a suitable candidate for the detection of PRRS virus-specific antibodies and diagnosis of PRRS. In the present study, the ORF7 gene encoding the N protein was cloned and expressed as a fusion protein with the glutathione S-transferase (GST) in Escherichia coli. The resulting GST-N recombinant protein was used as an antigen for an indirect sandwich enzyme-linked immunosorbent assay (i-ELISA). Expressed GST-N recombinant protein was migrated at 41 kDa and reacted with ORF7-specific monoclonal antibody by Western blotting. In order to increase the specificity of the ELISA for the detection of PRRS virus-specific antibodes, an i-ELISA was developed using an anti-GST antibody as a capture antibody. The sensitivity and specificity of developed i-ELISA were 92% and 96%, respectively. Based on these results, it was suggested that the i-ELISA is a simple and rapid test for screening a large number of swine sera for the anti-PRRS virus antibodies.

• Korean Journal of Veterinary Service
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• v.30 no.1
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• pp.51-66
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• 2007

The purpose of this study was to evaluate the effect of a subsequent infection of porcine reproductive and respiratory syndrome(PRRS) virus to pigs with A pleuropneumonia. Twenty three 7-week-old commercial pigs were infected intratracheally with PRRS virus and/or A pleuropneumoniae serotype 5. Serum antibody titers were examined by an enzyme-linked immunosorbent assay(ELISA) and proportion of porcine leukocyte subpopulations in peripheral blood was examined by flow cytometry. In this experiment, antibodies against PRRS virus and A pleuropneumoniae were detected at 2 weeks and 1 week postinfection and the number of antibody positive pigs were gradually increased. And in proportion to leukocyte subpopulations in peripheral blood of pigs infected with A pleuropneumoniae compared with pigs administrated with saline, the proportion of PoCD4 and N cells were increased(P<0.1). Furthermore, in proportion to leukocyte subpopulations in peripheral blood of pigs infected with PRRS virus followed by A pleuropneumoniae compared with pigs administrated with saline, the proportion of MHC class II, PoCD4 and B cells were significantly increased(P<0.1). The results indicated that dual infection with PRRS virus and A pleuropneumoniae induced the stronger immune responses associated with macrophages and Th cells in pigs than single infection with PRRS virus or A pleuropneumoniae.

• Journal of the korean veterinary medical association
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• v.45 no.2
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• pp.164-168
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• 2009

• Korean Journal of Veterinary Service
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• v.38 no.3
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• pp.163-166
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• 2015

The purpose of this study was to survey seroprevalence of porcine reproductive and respiratory syndrome (PRRS) virus and porcine circovirus-2 (PCV-2) in Gyeongbuk province by enzyme-linked immunosorbent assay (ELISA). A total of 966 samples collected from 21 pig farms were tested. The sero-positive rate of PRRS and PCV-2 were 77.6% (750/966) and 76.4% (738/966), respectively.

• Korean Journal of Veterinary Service
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• v.30 no.1
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• pp.85-93
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• 2007

The purpose of this study was to investigate the infection situation of several diseases (post-weaning atrophic pigs) such as porcine reproductive and respiratory syndrome (PRRS) in swine breeding complex in Jeonbuk-Iksan. From February to October in 2006, a total of 28 swine samples (6-10 week old) were collected from 6 farms and examined by polymerase chain reaction(PCR) and clinical signs. In the rate of single infection, pneumonia was top (32.1%), followed by salmonellosis (14.2%)and Glasser's disease (10.7%) and double infection pneumonia/Glasser's disease (17.8%) was detected. PCR was detected of PCV 2 from 28 (100.0%) and PPV 6 (21.4%), PRRS PORF6 10 (35.7%) and POR7 11 (39.2%), but HC and AD was not detected. The results suggest that PCV 2 is complex infection PRRS, PPV and bacterial disease.

• 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 Service
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• v.37 no.3
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• pp.151-156
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• 2014

Porcine reproductive and respiratory syndrome virus (PRRSV) causes major economic losses to the Korean pig industry. ELISA tests using recombinant nucleocapsid protein of PRRSV have been most commonly used for PRRS diagnostics. In the current study, two commercial PRRSV ELISA kits (Bionote PRRSV Antibody ELISA and IDEXX 3XR PRRS Antibody ELISA) have been compared using sera collected from 19 swine farms in various stages of PRRSV infection confirmed by professional diagnostic centers. Thus 130 sera collected from 5 different farms with active PRRSV infection, 130 sera from 6 different farms with PRRS-stabilized status, and 140 sera from 8 different farms with PRRS-free status were evaluated to determine the correlation of test results between those ELISA kits. Both ELISA kits showed a good correlation [PRRSV-positive farms ($R^2$=0.6375) and stabilized farms ($R^2$=0.8928)] in sample-to-positive (S/P) ratio va lues. Among the 140 sera from negative farms, one sample was falsely positive by either of the ELISA kits. In conclusion, both of the ELISA kits showed a good correlation when applied on field samples collected from farms at various stages of PRRSV infection. Bionote ELISA or IDEXX ELISA gave a false positive result on 1 out of 140 negative samples so their specificity was calculated as 99.3%. Therefore, Bionote ELISA would be a good complementary and alternative method for IDEXX ELISA kit, and vice versa.

• Korean Journal of Veterinary Service
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• v.37 no.1
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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.