• Journal of Veterinary Science
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• 제23권5호
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• pp.32.1-32.11
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• 2022

Background: Classical swine fever (CSF) is a severe infectious disease of pigs that causes significant economic losses to the swine industry. Objectives: This study developed a solid-phase blocking enzyme-linked immunosorbent assay (spbELISA) method for the specific detection of antibodies against the CSF virus (CSFV) in porcine serum samples. Methods: A spbELISA method was developed based on the recombinant E2 expressed in Escherichia coli. The specificity of this established spbELISA method was evaluated using reference serum samples positive for antibodies against other common infectious diseases. The stability and sensitivity were evaluated using an accelerated thermostability test. Results: The spbELISA successfully detected the antibody levels in swine vaccinated with the C-strain of CSFV. In addition, the detection ability of spbELISA for CSFV antibodies was compared with that of other commercial ELISA kits and validated using an indirect immunofluorescence assay. The results suggested that the spbELISA provides an alternative, stable, and rapid serological detection method suitable for the large-scale screening of CSFV serum antibodies. Conclusions: The spbELISA has practical applications in assessing the vaccination status of large pig herds.

• 한국임상수의학회지
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• 제31권4호
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• pp.293-297
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• 2014

Swine influenza is an acute respiratory disease prevalent in pig-growing areas worldwide. In total, 518 gilt and sow serum samples and 14 litters (66 samples) of aborted fetuses from 37 farms (average of 14 serum samples per farm) in Gyeongbuk Province were collected between September 2010 and May 2011. All samples were examined for antibodies to swine influenza virus (SIV) H1N1 and H3N2 using enzyme-linked immunosorbent assay (ELISA). The seropositive rates of gilt and sows were 59.8% (310/518) for SIV H1N1, 78.8% (408/518) for H3N2, and 55.6% (288/518) for both subtypes tested. The rate of aborted fetuses was 13.6% (9/66) for H1N1, 9.1% (6/66) for H3N2, and 9.1% for both subtypes. The seroprevalence for H1N1 in gilts and sows was 46.6% (69/148) and 65.1% (241/370), respectively, and that for H3N2 was 78.4% (116/148) and 78.9% (292/370), respectively.

• 한국동물위생학회지
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• 제13권1호
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• pp.64-68
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• 1990

This experiment was to investigate the Leptospiral antibody in the pigs with the serological test in two areas of Kangwondo from March to April. 1989. Twelve different living antigen (L. icterohaemorrhagiae, L. pomona, L. hardjo, L. australis, L. canicola, L. autumnalis, L. grippotyphosa, L. tarassovi, L. pyrogenes, L. bataviae, L. lai and L. ballum) of Leptospira interrogans was used for the serological test in the pigs. The blood sample of 280 pigs collected from the slaughter houses were detected by microscopic-agg-lutination test. The results were as follows, 1. Among the serum sample of 280 heads of the pigs, 6 heads of the swine (2.14%) were positive. 2. Among the positive sample of 6 heads, 3 heads of the swine (1.1%) showed the antibody of L. ict-erohaemorrhagiae, 2 heads of the swine (0.7%) showed the antibody of L. canicola, and 1 head of the swine (0.4%) showed the antibody of L. pomona. 3. The positive rate of Leptospira interrogans in the swine of Kangwondo appeared to be very low.

• Journal of Veterinary Science
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• 제23권4호
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• pp.51.1-51.10
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• 2022

Background: Due to the unavailability of an effective vaccine or antiviral drug against the African swine fever virus (ASFV), rapid diagnosis methods are needed to prevent highly contagious African swine fever. Objectives: The objective of this study was to establish the ladder-shape melting temperature isothermal amplification (LMTIA) assay for the detection of ASFV. Methods: LMTIA primers were designed with the p72 gene of ASFV as the target, and plasmid pUC57 was used to clone the gene. The LMTIA reaction system was optimized with the plasmid as the positive control, and the performance of the LMTIA assay was compared with that of the commercial real-time polymerase chain reaction (PCR) kit in terms of sensitivity and detection rate using 200 serum samples. Results: Our results showed that the LMTIA assay could detect the 10⁴ dilution of DNA extracted from the positive reference serum sample, which was the same as that of the commercial real-time PCR kit. The coincidence rate between the two assays was 100%. Conclusions: The LMTIA assay had high sensitivity, good detection, and simple operation. Thus, it is suitable for facilitating preliminary and cost-effective surveillance for the prevention and control of ASFV.

• 대한수의학회지
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• 제55권1호
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• pp.61-63
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• 2015

Proliferative enteropathy caused by Lawsonia intracellularis is one of the most common enteric diseases in pigs. The objective of this study was to determine the prevalence of serum antibodies against L. intracellularis in the general swine population of Korea from 2005 to 2008. In total, 8,008 swine serum samples obtained from 1,001 herds were tested. The samples were analyzed with an immunoperoxidase monolayer assay to detect anti-L. intracellularis antibodies. The overall 4-year average true prevalence was 40.0% (CI: 39.4 - 40.6%) at the individual animal level and 71.9% (CI: 70.3-73.4%) at the herd level.

• 한국동물위생학회지
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• 제23권3호
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• pp.289-299
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• 2000

The study was performed to investigate the distributions of swine pleuropneumonia in Kyongbuk western area by the enzyme-linked immunosorbent assay (ELISA). Sera collected from 400 slaughtered pigs in 3 slaughter houses during the period from May 1999 to october 1999 were tested to detect antibodies against A pleuropneumonie serotype 2 and 5. The optimal dilution of CBE antigen, conjugate and serum for this ELISA were determined 1 : 400, 1 : 20,000, 1 100, respectively. The optimal dilution of OW antigen, conjugate and serum for this ELISA were determined 1 : In, 1 : 20,000, 1 : 200, respectively. Cut-off value in this ELISA was determined by mean absorbance (at 492 nm) of negative control sera added with the triple value of the standard deviation. Cut-off value in ELISA by CBE and OMP antigen were 1.134 and 1.217, respectively. By the ELISA, positive reaction rates to A pleuropneumoniae serotype 2 and 5 for CBE antigen were 38.8% and 18.8%, and for OMP antigen were 42.8% and 23.5% of the 400 samples, respectively.

• Journal of Veterinary Science
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• 제22권3호
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• pp.29.1-29.6
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• 2021

West Nile virus (WNV), a neurotropic arbovirus, has been detected in mosquitos, birds, wildlife, horses, and humans in Malaysia, but limited information is available on WNV infection in Malaysian pigs. We tested 80 archived swine serum samples for the presence of WNV antibody and West Nile (WN) viral RNA using ID Screen West Nile Competition Multi-species enzyme-linked immunosorbent assay kits and WNV-specific primers in reverse transcription polymerase chain reaction assays, respectively. A WNV seroprevalence of 62.5% (50/80) at 95% confidence interval (51.6%-72.3%) was recorded, with a significantly higher seroprevalence among young pigs (weaner and grower) and pigs from south Malaysia. One sample was positive for Japanese encephalitis virus antibodies; WN viral RNA was not detected in any of the serum samples.

• International Journal of Industrial Entomology and Biomaterials
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• 제29권2호
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• pp.207-213
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• 2014

The structural proteins of classical swine fever virus (CSFV) consist of nucleocapsid protein C and envelope glycoprotein $E^{rns}$ (E0), E1 and E2. Among them, E2, the most immunogenic of the CSFV glycoproteins, induces a protective immune response in swine. In this study, to determine the optimal expression conditions of glycoprotein E2 using baculovirus system, we investigated the influence of insect cells and media to the expression of recombinant E2. Recombinant virus containing glycoprotein E2 coding gene was constructed with bApGOZA DNA. Expression of the glycoprotein E2 was analyzed by SDS-PAGE and Western blot analysis using anti-CSFV E2 monoclonal antibodies. Expression of glycoprotein E2 in Sf21 cells was first observed after 3 days and reached a maximum on the 5th day after infection. Furthermore, the highest levels of glycoprotein E2 expression were observed at multiplicity of infection (MOI) of 5. When three different insect cell lines (Sf21, High-Five and Se301) were tested, High-Five cells showed the highest production. In addition, four different serum-free and serum-supplemented media, respectively, were tested for the expression of glycoprotein E2 and the budded virus (BV) titers. As a result, serum-supplemented medium provided the best conditions for protein production and the BV yield.

• 대한수의학회지
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• 제29권4호
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• pp.567-575
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• 1989

This study was conducted to evaluate the possibility of application of a microenzyme-linked immunosorbent assay(micro-ELISA) for the serodiagnosis of specific toxoplasma antibodies in swine sera and this test was performed as a microplate system by coating the polystyrene plates with toxoplasma soluble antigen, incubated serially diluted sera, then added horse radish peroxidase labelled goat anti-swine IgG(r) conjugate followed by o-phenylenediamine as substrate. The color development by enzyme-substrate reaction was determined by the photometric reading [ELISA reader at 490nm (OD)] and visual reading. The soluble antigen was prepared from the tachyzoites in mouse peritoneal cavity. A total of 1,200 swine sera from pig slaughter-house and a total of 116 swine sera from pig breeding station (S-C farm) were tested for the detection of antibodies to Toxoplasma gondii. The results obtained were summarized as follows: 1. The optimal reactions of indirect ELISA for the test sera were determined by the dilution of antigen 1:256 and 1:3,200 of horse radish peroxidase conjugate [anti-swine IgG(r)]. 2. The specific togoplasma antibody(IgG) in pigs infected with Tp artificially were detected as the serum titers of 1:64 or 1:128 at one week postinfection. 3. Of a total of 1,200 swine sera from pig slaughter-house 505 samples of sera were detected as positive (42.1%) and of a total of 116 swine sera from S-C pig breeding station 68 samples of sera as positive (58.6%). 4. The specific antibody(IgG) detection rates against a total of 1,200 test sera from pig slaughter-house were not significant between male (43.1%) and female (40.7%). 5. The indirect ELISA was proved to be a sensitive and specific procedure for the serodiagnosis of swine toxoplasmosis and also evaluated as an effective screening test for the large scale of test samples in laboratory.

• 대한수의학회지
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• 제44권3호
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• pp.449-454
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• 2004

Ninety pigs under the age of 120-day-old requested at the diagnostic laboratory of animal diseases in Cheju National University were evaluated for the prevalence of tissue antigen and serum antibody to swine influenza virus (SIV). For histopathologic examination there was sampled at the consolidated area in cranioventral or dorsocaudal lobes of lungs. Lung tissues from all pigs were tested for the antigen of SIV type A by immunohistochemistry (IHC). Sera from 56 pigs were used for the antibody detection to SIV type A (subtype H1N1 and H3N2) by haemagglutinin inhibition test. Pneumonic lesions were observed in 72 cases (80%) of 90 pigs. Broncho-interstitial or interstitial pneumonia were more prevalent than suppurative or fibrinous bronchopneumonia. According to HI test, 46.4% of the tested sera showed seropositive. Positive sera were consisted with 5.3% for SIV H1N1, 28.6% for SIV H3N2, and 12.5% for both subtype to be tested, respectively. SIV antigens were detected in 51 cases(56.6%) of 90 pigs. Most SIV antigens were presented in the epithelium of the bronchi and bronchiole. Necrotizing bronchitis or bronchiolitis were observed in 28(31.1%) cases of all inspected pigs. These results suggested that SIV might be an important role to induce swine pneumonia in Jeju. Also IHC was very useful for the detection of SIV in the lung.