• 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 Service
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• v.23 no.3
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• pp.271-279
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• 2000

This study was carried out to provide the fundamental information for development of proper vaccination program against infectious bursal disease(IBD) to the local chicken farms. The antigen detection was peformed from 8 samples of bursa of Fabricius with agar gel precipitation(AGP) and indirect immunofluorescent assay(IFA), And also, the antibodies in serum samples were detected by the various serological methods such as commercial ELISA assay, AGP and virus neutralization(VN) test. 1. The antigen detection rates were 25% for AGP which is 2 out of 8 farms and 10 out of 40 bursas, and 25% which Is 2 out of 8 farms and 20% 8 out of 40 bursas for IFA, respectively. 2. The mean titer of maternal antibody (>3,000) existed until 10 days of the age with ELISA-GMT. 3. The antibody positive rates which are over 80% showed until 5 days of the age with ELISA and at 10 days of the age with AGP except one, but none of them showed from 1 day of the age. This report came to conclusions that both the protective maternal antibody titers and the antigen positive rates were significant until at the 10 days of the age.

• Korean Journal of Veterinary Research
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• v.39 no.1
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• pp.111-117
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• 1999

A nation wide sero-epidemiological survey of porcine reproductive and respiratory syndrome(PRRS) was carried out to analyze the current status of the PRRS virus infections in the field using the indirect immunofluorescent antibody assay(IFA) with the field isolate PL96-1. Since the first report of the antibody detection to PRRSV in 1993, the prevalence of seropositive pigs has increased dramatically and the data indicate that over 21% of the pigs and around 60% of the farms showed seropositives to the PRRS virus. A slightly higher positive rate was recognized in breeders than fattenings and it might be due to the higher age at the time of testings. No significant regional differences were detected in the sero-epidemiological survey. Higher sero-positive rate in growers indicates that PRRSV infection in the field was common after weaning(around 40 days). However, the number of seropositive pigs were declined in fattening pigs. Sows showed around 26% of sero-positive rate that there is a higher chance of continuous virus circulation in the infected farms. Low rate of sero-positivity in boars(9.8%) implies that there is high demand in proper control measures to prevent virus spreading through breeding procedures such as natural or artificial insemination. Therefore it was concluded that PRRSV infection in domestic swine herds is endemic and the positive rate and economic loses will be increased by spontaneous infections in naive farms.

• Korean Journal of Veterinary Service
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• v.35 no.1
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• pp.19-24
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• 2012

This study was performed to evaluate the prevalence rate of Toxoplasma gondii on 217 stray cats in Daejeon. The positive infection rate of T. gondii was 15.7% in enzyme-linked immunosorbent assay (ELISA), 12.4% in latex agglutination test (LAT), 14.7% in indirect immunofluorescent antibody test (IFA) and 0.5% in polymerase chain reaction (PCR) respectively. In districts, Yuseong-gu was shown the highest seropositive rate of T. gondii as 31.8% in ELISA, 22.7% in LAT and 31.8% in IFA. In gender, the seropositive rate of female cats was slightly higher than that of male cats as 17.2% in ELISA, 15.2% in LAT, 15.2% in IFA and 1.0% in PCR. Cats captured in National science museum, detached house and apartment was shown relatively high prevalence rate of T. gondii.

• Korean Journal of Veterinary Research
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• v.40 no.1
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• pp.81-85
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• 2000

Coxiella burnetii (C burnetii) is the causative agent of Q fever in animal and human. The distribution of the disease has been documented around world. In this study we developed the competitive enzyme linked immunosorbent assay(cELISA) and compared it with indirect immunofluorescent assay(IFA). A monoclonal antibody(Mab) against C burnetii and a peroxidase-conjugated anti-mouse IgM were used as an indicator system competing against antibody in animal serum or as an indicater of the absence of antibody. Sera were considered antibody positive when the percentage inhibition index(PI index) is upper than 30. PI index is calculated as 100-[sample OD/Mab OD)${\times}100$]. Among 162 bovine serum samples, 23 samples were antibody positive both in cELISA and IFA. And 156 samples showed same results. From goat with experimentally induced infection with C burnetii the antibody was detected 20 days early in cELISA compared to IFA. On the basis of present findings, it was demonstrated that cELISA is a reliable diagnostic method for The detection of specific antibodies against C burnetii infection.

• The Journal of Korean Society of Virology
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• v.26 no.1
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• pp.59-65
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• 1996

For easy and rapid screening of hemorrhagic fever with renal syndrome (HFRS) without any laboratory equipment, dot blot enzyme immunoassay was developed and tried to detect anti-hantavirus antibodies. The nucleocapsid protein of Hantaan virus was isolated by affinity chromatography and used for making the dot strip. 28 of 29 Hantaan virus infected sera showed positive signals and 21 of 22 HFRS negative sera showed no positive signals. Anti-Seoul virus monoclonal antibody also exibited positive signal but the intensity of colorization was approximately 5 fold less than that of anti-Hantaan monoclonal antibody. The sensitivity of dot blot assay was equal or superior to indirect immunofluorescent assay (IFA) or ELISA test. Overall, the screening results with dot blot assay showed 92.2 % of concordance with IFA or ELISA test. This results suggests that dot blot assay could be applied a tool for easy and rapid screening of HFRS.

• Korean Journal of Veterinary Service
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• v.24 no.2
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• pp.127-132
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• 2001

Porcine circoviruses(PCV) are the smallest nonenveloped DNA viruses containing a unique single-stranded circular genome. No recognized link was found between PCV infection of pig and disease. But the PCV consistently identified from postweaning multisystemic wasting syndrome(PMWS) and researches indicate that there are strong relationships between PCV and PMWS. Clinical signs were emaciation, dyspnea, high fever with normal appetite. Necropsy findings showed respiratory disease complex lesion and lymph node anomalities. An indirect-immunofluorescent antibody procedure was used to assay swine sera for the presence of PCV atibodies. Antibodies against PCV were found in an average of 20% of the samples tested. The PCV DNA was amplified from lymph nodes collected from pigs. PCV specific primers were successfully amplified PCV DNAs. Further studies are needed to determine the possible role this virus might have in disease.

• Korean Journal of Veterinary Research
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• v.42 no.3
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• pp.377-382
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• 2002

Bovine piroplasmosis caused by Theileria sergenti is a major cause of economic loss in livestock industry. Five cattle infected with Theileria sergenti showing severe and fatal anemia, confirmed by indirect immunofluorescent assay(IFA), were used in this study. Four cattle were treated with diminazene aceturate and one was not treated as the control. The therapeutic effect of diminazene aceturate against Theileria sergenti infection was monitored by detecting the 32kDa polypeptide specific for Theileria sergenti by the western blotting with both polyclonal and monoclonal antibodies. The 32kDa polypeptide detected at the beginning of diminazene aceturate treatment was not detectable after the treatment. It is postulated that the detection of the 32kDa polypeptide specific for Theileria sergenti may be a good tool for the diagnosis and monitoring the treatment progress of Theileria sergenti infection.

• Korean Journal of Veterinary Research
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• v.38 no.4
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• pp.859-866
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• 1998

This study was carried out to investigate the prevalence of Neopsora (N) caninum infection in Korean dairy herds. To determine the prevalence of antibodies to N caninum in Korean dairy cattle, a total of 1,688 sera including 895 sera taken from 30 herds having recent high abortion rate and 793 sera selected randomly from 168 herds with no history of recent abortion problem, respectively, collected nationwide during a designated period were analyzed by indirect fluorescent antibody (IFA) test. Mean nationwide seropositive rate of the sera tested in herds and individual cattle tested were 53.5% and 35.6%, respectively. However mean seropositive rate of the samples from herds having abortion problem was approximately two and half times higher than those in herds with no recent abortion history. Regional seropositive rates of the samples from the herds with abortion problem were 48.6%, 51.6%, 44.4% and 71.4% at Kyunggi, Kangwon, Kyungbuk and Jeonnam province, respetively. Regional seropositive rates of the samples from the herds with no recent abortion problem were 35.6%, 18.3%, 16.5%, 37.5%, 19.4%, 33.3%, 32.1%, 3.8% and 0.0% at Kyunggi, Kangwon, Chungbuk, Chungnam, Kyungbuk, Kyungnam, Jeonbuk, Jeonnam and Jeju province, respectively. The results of this study suggested that N caninum infection was widespread and considerably associated with bovine abortion in Korea.

• Parasites, Hosts and Diseases
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• v.34 no.4
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• pp.255-258
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• 1996

Eight 2-day-old SPF Chickens were each inoculated Orally With 3 Sing1e dose Of 5 × 105 oocysts of Cryptosporinium boilevi. and immunoglobulin G (IgG) antibody responses were chronologically measured by indirect immunofluorescent antibody (IFA) assay. Anti-C. bcileyi IgG antibody levels remained high (1 : 106.67 to 1:512.00) for at least 4 months with 330 days of a detectable period. Ten days after the negative conversion, each chicken was re-challenged with 1 × 107 oocysts of the same species. Subsequent infection in 340-day-old individuals caused sudden elevated IgG antibody levels and the titer peaked on day 28 postchallenge inoculation (PCI), at 1:1.024 with a 65 days of detection period. Chickens in primary infection showed oocyst shedding profiles. but did not exhibit any oocyst shedding before or after experimental reinfection.