• Food Science of Animal Resources
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• v.32 no.6
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• pp.706-712
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• 2012

The present study was aimed to produce a chicken polyclonal antibody against Cronobacter muytjensii and to develop an immunoassay for its detection. Purification of anti-C. muytjensii IgY from egg yolk was accomplished using various methods such as water dilution and salt precipitation. As a result, sodium dodecyl sulfate-polyacrylamide gel electrophoresis produced two bands around 30 and 66 kDa, corresponding to a light and a heavy chain, respectively. Indirect competitive enzyme-linked immunosorbent assay (IC-ELISA) was performed to determine the effectiveness of the chicken IgY against C. muytjensii. The optimum conditions for detecting C. muytjensii by indirect ELISA and checkerboard titration of the antigen revealed an optimum average absorbance at the concentration of 18 ${\mu}g/mL$, having ca. $10^8$ coated cells per well. The anti-C. muytjensii IgY antibody had high specificity for C. muytjensii and low cross-reactivity with other tested pathogens. In this assay, no cross-reactivity was observed with the other genera of pathogenic bacteria including Escherichia coli O157:H7, Salmonella Typhimurium, Staphylococcus aureus, Bacillus cereus, Enterobacter aerogenes, Salmonella Enteritidis and Listeria monocytogenes. In addition, detection of C. muytjensii in infant formula powder showed a low matrix effect on the detection curve of IC-ELISA for C. muytjensii, with similar detection limit of $10^5$ CFU/mL as shown in standard curve. These findings demonstrate that the developed method is able to detect C. muytjensii in infant formula powder. Due to the stable antibody supply without sacrificing animals, this IgY can have wide applications for the rapid and accurate detection of C. muytjensii in dairy foods samples.

• Journal of Food Hygiene and Safety
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• v.3 no.2
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• pp.65-73
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• 1988

T-2 toxin is one of mycotoxins produced by fungi such as Fusarium spp. and possesses a potent cytotoxicity to eukaryotic cell. The contamination of mycotoxins in cereals and feedstuffs is one of the great concerns in health authorities. Therefore, the development of the specific, sensitive and simplified analysis method for T -2 toxin is required. During more than ten years, several chemical and biological analysis methods were proposed and applied for the detection and quantification of T-2 toxin. TLC, GLC-FID and GC-MS are widely employed, but these methods required numerous clean-up procedures before analysis, and the detection limit for T-2 toxin is more than 10 ppb. Biological analysis methods with dermal tissues and cultured cells are not specific to T-2 toxin, since T-2 toxin and other related derivatives possess a similar toxicological activity although their relative activity is different each otber. Based on tbe specific reaction between antibody and antigen, the authors tried to introduce the immunochemical methods for determination of T-2 toxin. The enzyme-linked immunosorbent assay method using monoclonal antibody for T-2 toxin was applied to analyse T-2 toxin. The detection limit of T-2 toxin by ELISA method was 0.1 ppb. The correlation between ELISA and GC-MS method on these samples was very high. ELISA method developed for the detection and quantification of T -2 toxin in this paper possesses simplicity, high sensitivity and specific for T-2 toxin. Furthermore, the ELISA method with T-2 toxin monoclonal antibody was an excellent tool for the screening of Fusarium spp. which was suspected to produce T-2 toxin.

• Journal of Food Hygiene and Safety
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• v.8 no.4
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• pp.205-214
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• 1993

The monoclonal antibody to chloramphenicol(CAP) was produced to develop an enzyme-linked immunosorbent assay(ELISA) for residual CAP. An immunogen(CAP-BSA) was prepared by immunogen, antibody titer was measured by indirect ELISA. Spleen cells form the immunized mouse were fused with SP2/OAg14 myeloma cells. Among hybridomas selected in HAT media, 6 clones shown high antibody titer to CAP were subjected to cloning by limit dilution, and all of the monoclonal antibodies(MCA1, 2, 3, 4, 5, 7 and 9) produced by each clone were identified as IgG1 by ELISA isotyping analysis. Competitive ELISA condition was established by using the purified monoclonal antibody MCA1 as primary antibody and CAP-HSA conjugate as coating antigen. Standard curve of CAP(n=28) showed that the lowest detection limit of CAP is 20ng/ml level. The cross-reactivities of the 6 monoclonal antibodies showed that CAP sodium succinate. CAP base, P-nitrophenol, and p-nitrobenzyl alcohol were 89∼178, 0.050∼2.237, 0.056∼0.794 and 0.013∼7.939%, respectively. No cross-reactivities were observed with phenylalanine, tyrosine, glutamine, thiamphenicol, neomycin, streptomycin, gentamicin, sulfamethazine, sulfathiazole, chlortetracycline and p-aminobenzoic acid.

• Reproductive and Developmental Biology
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• v.34 no.3
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• pp.161-167
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• 2010

Early diagnoses of pregnancy for animal such as swine and bovine is extremely important to increase income of a farmhouse and for the management of farm. For the development of immunoasaay system of pregnancy in swine, we report a competitive heterologous enzyme linked immunosorbent assay (ELISA) for the direct measurement of oestrone sulfate (E1S) in diluted urine using anti-E1G (glucuronide) monoclonal antibody which cross react with ElS. The principle of assay was based on the typical solid-phase competitive ELISA methods using E1G-HRP (horseradish peroxidase) as a tracer and E1S for standard. The method had a reasonable sensitivity for the detection of E1S with 0.15 ng/ml as a detection limit. The intra-assay and inter-assay precisions were raging coefficient of from 8.50~9.67% and 8.50~9.87%, respectively, which were quite acceptable. In a field trial with a group 37 sows (18 non-pregnancy and 19 pregnancy sows) after day 29~30 post service, the concentration of E1S were determined to be below 30 ng/ml in all non-pregnancy group and over 48 ng/ml in pregnancy group except one sample. The method described here, heterologous ELISA for the measurement of E1S in urine is good enough for monitoring the early pregnancy test of swine.

• Journal of Microbiology and Biotechnology
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• v.23 no.1
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• pp.69-75
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• 2013

Enrofloxacin is a fluoroquinolone antibiotic approved for the treatment of infections in animals. Because of the side effects to consumers of animal products, the maximum residue limits (MRLs) of enrofloxacin in animal tissues for consumption are regulated. In this study, a monoclonal antibody (mAb) against enrofloxacin was prepared and characterized for the development of a direct competitive enzyme-linked immunosorbent assay (ELISA). The obtained mAb, Enro44, was highly specific for enrofloxacin and had a 50% inhibition concentration ($IC_{50}$) of 1.99 ng/ml in a competitive ELISA, and the limit of detection (LOD) was 0.50 ng/ml. The cross-reactivity of the mAb with other quinolones and fluoroquinolones was lower than 0.01%. The subclass of the mAb Enro44 was identified as IgG1. The antigen (Ag)-captured direct competitive ELISA using the mAb Enro44 was tested on different spiked samples, including chicken muscle, cattle milk, and cattle urine, and the assay demonstrated recoveries of 82-112%, 80-125%, and 78-124%, respectively. Furthermore, the quantitation of enrofloxacin obtained from the ELISA and from high-performance liquid chromatography (HPLC) was in good agreement, with the linear regression coefficient between 0.933 and 1.056. The cDNAs encoding a heavy-chain Fd fragment (VH and CH1) and a light chain of the mAb Enro44 were cloned and sequenced. Taken together, the results obtained reveal a potential use of this mAb in an ELISA for the detection of enrofloxacin in food samples. The information of amino acid sequence of this mAb will be useful for further modification and production of the mAb in a bioreactor.

• Parasites, Hosts and Diseases
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• v.54 no.3
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• pp.375-380
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• 2016

Angiostrongyliasis is difficult to be diagnosed for the reason that no ideal method can be used. Serologic tests require specific equipment and are not always available in poverty-stricken zone and are time-consuming. A lateral flow immunoassay (LFIA) may be useful for angiostrongyliasis control. We established a LFIA for the diagnosis of angiostrongyliasis based on 2 monoclonal antibodies (mAbs) against antigens of Angiostrongylus cantonensis adults. The sensitivity and specificity were 91.1% and 100% in LFIA, while those of commercial ELISA kit was 97.8% and 86.3%, respectively. Youden index was 0.91 in LFIA and 0.84 in commercial ELISA kit. LFIA showed detection limit of 1 ng/ml of A. cantonensis ES antigens. This LFIA was simple, rapid, highly sensitive and specific, which opened an alternative approach for the diagnosis of human angiostrongyliasis.

• Journal of Veterinary Science
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• v.23 no.3
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• pp.50.1-50.12
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• 2022

Background: There is an urgent need to find reliable and rapid bovine tuberculosis (bTB) diagnostics in response to the rising prevalence of bTB worldwide. Toll-like receptor 2 (TLR2) recognizes components of bTB and initiates antigen-presenting cells to mediate humoral immunity. Evaluating the affinity of antigens with TLR2 can form the basis of a new method for the diagnosis of bTB based on humoral immunity. Objectives: To develop a reliable and rapid strategy to improve diagnostic tools for bTB. Methods: In this study, we expressed and purified the sixteen bTB-specific recombinant proteins in Escherichia coli. The two antigenic proteins, MPT70 and MPT83, which were most valuable for serological diagnosis of bTB were screened. Molecular docking technology was used to analyze the affinity of MPT70, MPT83, dominant epitope peptide of MPT70 (M1), and dominant epitope peptide MPT83 (M2) with TLR2, combined with the detection results of enzyme-linked immunosorbent assay to evaluate the molecular docking effect. Results: The results showed that interaction surface Cα-atom root mean square deviation of proteins (M1, M2, MPT70, MPT83)-TLR2 protein are less than 2.5 A, showing a high affinity. It is verified by clinical serum samples that MPT70, MPT83, MPT70-MPT83 showed good diagnostic potential for the detection of anti-bTB IgG and M1, M2 can replace the whole protein as the detection antigen. Conclusions: Molecular docking to evaluate the affinity of bTB protein and TLR2 combined with ELISA provides new insights for the diagnosis of bTB.

• Biomedical Science Letters
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• v.3 no.2
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• pp.95-105
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• 1997

Currently, the laboratory diagnosis for lyme disease have been performed with the detection of antibodies against Borrelia burgdorferi. However there might be some difficulties in the interpretation of obtained results due to the usage of foreign isolates as an antigen in the test. Therefore the optimization of serological tests with Korean isolates of B. burgdorferi as an antigen would be needed to establish the standardized diagnostic method for the detection of antibodies against B. burgdorferi infection. In this study, the optimization of ELISA was investigated with experimentally challenged rabbit sera and sonicated B. burgdorferi antigens of Korean isolates. Of 217 human patient's sera with unknown fever, the mean seropositivities in ELISA, done under the optimized conditions obtained in this study, were found to be about 8％ against B. burgdorferi sensu late, showing the highest seropositivity of 14.3％ against B. afzelii. In immunoblotting assay with ELISA-positive human sera, the major reactive bands were 41kDa (flagellin) which might be the indication of early infection, and 27kDa, 31kDa (OspA), 34kDa (OspB) which are the characteristics of late infection. Obtained results in this study might strongly indicate the possibility of B. burgdorferi infections in Korea.

• Korean Journal of Veterinary Service
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• v.34 no.1
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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.

• Korean Journal of Veterinary Research
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• v.37 no.2
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• pp.349-358
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• 1997

Mycobacterium paratuberculosis is the etiologic agent of Johne's disease, a chronic inflammatory bowel syndrome in ruminants. The attempts to control or eradicate the disease were severely hampered by the inadequacies of present diagnostic methods. The first purpose of this study was to detect Johne's disease out of 577 cows in the province of Kyunggi, Chungchong, Gangweon and the second purpose was to compare the results of non-absorbed ELISA, absorbed ELISA, PCR, and conventional culture methods. The third purpose was to increase diagnostic specificity, accuracy and rapidity. When non-absorbed ELISA test was conducted with Mycobacterium paratuberculosis antigen, the prevalence of positive was 10.9%. To increase diagnostic specificity, absorbed ELISA test with Mycobacterium phlei was used. In this test, the positive prevalence was 1.7%. For the specific detection of Mycobacterium paratuberculosis, PCR was applied to bacterial culture obtained from fecal samples of cattle. The DNA sequences derived from IS900 were used to prepare DNA primers for detection and identification of Mycobacterium paratuberculosis by PCR. PCR for M paratuberculosis isolated from fecal cultures amplified specific target DNA. PCR was much more rapid than that obtained by conventional culture technique in diagnosis of Johne's disease.