• The Korean Journal of Food And Nutrition
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• v.26 no.4
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• pp.936-944
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• 2013

Cronobacter muytjensii is an important foodborne pathogen as a potential risk in infant formula powder (IFP). To develop a new and sensitive method for the detection of Cronobacter spp. in IFP, an immunoglobulin G (IgG) specific for C. muytjensii (formerly known as Enterobacter sakazakii ATCC 51329) was developed. Further, an indirect noncompetitive enzyme-linked immunosorbent assay (INC-ELISA) was developed by using the anti-C. muytjensii IgG. As a result, this newly developed INC-ELISA method was found very sensitive for C. muytjensii with detection limit of $6.5{\times}10^3CFU/ml$ in pure culture and 1 cell/25 g of IFP. This INC-ELISA method also displayed excellent specificity for C. muytjensii showing no cross-reactivity with other strains of Cronobacter genus and 11 other foodborne pathogenic strains. These results show that the developed INC-ELISA method was very sensitive, efficient, and rapid for the detection of C. muytjensii. Hence, this method could be applied to the development of diagnostic kits for the rapid and easy detection of C. muytjensii.

• 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.

• Parasites, Hosts and Diseases
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• v.55 no.3
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• pp.247-254
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• 2017

ELISA has been used for the diagnosis of toxoplasmosis, but it is being gradually replaced by a rapid diagnostic test (RDT). We compared and analyzed ELISA and RDT results using the sera collected during 4 consecutive years from residents of Gyodong-do (Island), Incheon-city, Korea. Sera from 921, 993, 940, and 838 adult residents were collected on a yearly basis (2010-2013). ELISA was performed by using a crude extract of T. gondii RH strain antigen and IgG/IgM RDT mounted with recombinant fragment of major surface antigen (SAG1), GST-linker-SAG1A, were applied to the sera. Comparison between groups was analyzed by the Student's t-test. The positive seroprevalence surged from 14.7% (135/921, 2010), 23.1% (231/993, 2011), 23.6% (222/940, 2012), and 32.1% (269/838, 2013) by ELISA. In contrast, RDT showed a more moderate increasing trend from 21.7% (200/921, 2010), 25.5% (253/993, 2011), 28.9% (272/940, 2012) and 33.1% (277/838, 2013). Discrepancies between ELISA and RDT were noted near the cut-off value. At the OD 0.15-0.24 range, RDT could detect 16.1% (169/1051) more positives, which suggests an early or acute toxoplasmosis, but at the OD 0.25-0.34 range, ELISA could detect 35.9% (92/256) more positives of possible chronic infections. Over the OD > 0.35 ELISA and RDT agreed in the majority of the cases. This surge in seroprevalence may be caused by the organic agriculture in addition to eating behavior or increase in pets among Koreans. These facts may be applied on a full-scale national survey using RDT to supplement ELISA to define the characteristics of the infection.

• Korean Journal of Veterinary Service
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• v.46 no.4
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• pp.325-334
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• 2023

Edema disease (ED) in pigs is enterotoxemia caused by Shiga toxin type 2e (Stx2e)-producing Escherichia coli (STEC) and frequently occurs in young piglets. Therefore, ED causes enormous economic losses in pig farms. In this study, a modified Stx2e (mStx2e) antigen was expressed and purified using commercial E. coli expression system. Monoclonal antibody was serviced by Ynto Ab Inc., using Phage Display Technique. Anti-Stx2e antibodies in piglets were measured by indirect ELISA using mStx2e antigens. Naive Stx2e in piglets were detected by Sandwich ELISA using Stx2e-monoclonal antibodies and commercial Stx2e-polyclonal antibodies. Among 3,480 piglets, anti-Stx2e antibodies were observed in 2,573 piglets. The 49.4% among 830 piglet serum samples possessed 0.625 ㎍/mL or more of Stx2e proteins. The 18.3% of 830 sera had 0.313 ㎍/mL of Stx2e proteins. The 32.3% of 830 samples held 0.156 ㎍/mL or less of Stx2e proteins. These results show that indirect ELISA using mStx2e antigen and Sandwich ELISA using Stx2e-monoclonal and polyclonal antibodies can be useful to detect ED in piglets.

• Annals of Laboratory Medicine
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• v.39 no.1
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• pp.50-57
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• 2019

Background: The Automated Fluorescent Immunoassay System (AFIAS) rotavirus assay (Boditech Med Inc., Chuncheon, Korea) is a new rapid antigen test for rotavirus detection. We evaluated the performance of this assay for detecting rotaviruses and their specific genotypes in clinical stool samples. Methods: AFIAS rotavirus assay was performed in 103 rotavirus-positive and 103 rotavirus-negative stool samples (confirmed by both PCR and ELISA), and its results were compared with those of PCR, ELISA, and immunochromatographic assay (ICA). We evaluated diagnostic sensitivity/specificity, the detectability of rotavirus subtypes, lower limit of detection (LLOD), reproducibility, cross-reactivity, and interference of AFIAS rotavirus assay. Results: Based on PCR and ELISA results, diagnostic sensitivity and specificity of the AFIAS rotavirus assay were both 99.0%. LLOD results showed that the AFIAS assay had sensitivity similar to or greater than ICA and ELISA. High reproducibility was confirmed, and no cross-reactivity or interference was detected. This assay could detect genotypes G1P[8], G2P[4], G3P[8], G4P[6], G4P[8], G8P[4], G8P[8], G9P[4], and G9P[8]. Conclusions: The AFIAS rotavirus assay showed high reproducibility, sensitivity, and specificity as well as excellent agreement with ELISA, PCR, and ICA. It detected the most common as well as unusual genotypes of rotavirus prevalent in Korea. It could be a useful onsite assay for rapid, convenient, and cost-effective detection of rotavirus infection.

• Bulletin of the Korean Chemical Society
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• v.26 no.6
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• pp.939-942
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• 2005

For the detection of cyanobacterial toxin, an Enzyme-linked immunosorbent assay (ELISA) was integrated into a PDMS microchip. The conjugates of microcystin-LR (MCLR) and keyhole limpet hemocyanin (KLH) were adsorbed on the surface of polystyrene beads and these MCLR-KLH polystyrene beads were introduced into a microchamber. MCLR on the surface of polystyrene beads reacted with horseradish peroxides (HRP) conjugated anti-MCLR monoclonal antibody (mAb) which had a competitive reaction with MCLR in water sample. After the enzyme substrate 3,3,5,5-tetramethyl benzidine (TMB) was injected into the chamber and catalyzed by HRP, the color change was detected with a liquid-cord waveguide. This integration shortened the conventional ELISA analysis time from several hours to about 30 min with only 4.2 $\mu$L MCLR sample consuming which was useful for the environmental analysis. More over, troublesome operations required for ELISA could be replaced by simple operations. The microchip based detection system showed a good sensitivity of 0.05 $\mu$g/L and maintained good reliability through its quantitative range with low coefficients of variation (2.5-10.5%).

• Journal of Microbiology and Biotechnology
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• v.9 no.4
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• pp.386-392
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• 1999

A large-scale culture of hepatitis A virus in human diploid MRC-5 cells was conducted. In a roller bottle culture, the virus was grown to a maximum titer in 3 weeks after infection. Over 95％ of the cell-associated virus was excreted after culturing the infected cells in suspension media without fetal bovine serum for 3 days. The cultured virus was inactivated with formalin, concentrated by ultrafiltration, and partially purified by ultracentrifugation in a non-ionic gradient medium of Renocal. Two separate peak fractions showing high anti-HAY ELISA titer were pooled and about 40％ of HAV antigen was recovered by this purification procedure. Of the partially purified vaccine, the protein pattern in SDS-PAGE and immunogenicity in mice were compared with a commercial HAV vaccine. In SDS-PAGE, the purified vaccine in this study and the commercial vaccine showed almost the same protein pattern. The seroconversion rate of the purified vaccine in mice was not different from that of the commercial vaccine. Therefore, we could prepare a good grade of HAV vaccine by a simple purification procedure although the purification itself was not completed.

• Korean Journal of Veterinary Service
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• v.28 no.2
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• pp.99-106
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• 2005

This survey was carried out to investigate the seroprevalence of antibodies to Neospora caninum in Korean indigenous cattle that was representative livestock raised in Jeongeup province Jeonbuk Korea. A total of 1,162 sera were tested for N caninum antibodies using ELISA (Herdcheck anti-Neospora. IDEXX Laboratories Inc., Westbrook, Maine USA). $15(1.3\%)$ sera were positive by ELISA. A total of 290 farms were tested. $11(3.8\%)$ farms were positive. Among the seroprevalence of cattle according to the areas, 8 of 44 counties were infected N caninum. Sero-positive 11 farms of N caninum antibodies using ELISA test and 62 of 301 sera $(20.6\%)$ were infected to N caninum. We found that cattle be raised in Jeongeup province was slightly infected to N caninum. It seems to be infected of N caninum an early stage. but the positive rates was variable that it was $6\%\~62\%$. It was supposed to the highest positive rate of 3 farms had some factors to be infected. The factors were supposed to keep dogs yearly, located the base of hills, and almost feed with imported dried grass. Farmers suppose to the cause of abortion was not the neosporosis but also broke out an accident or was infected Brucella spp. The results of Brucella Rose Bengal Test (RBT) were all negative.

• IMMUNE NETWORK
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• v.14 no.3
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• pp.164-170
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• 2014

JL1, a specific epitope on CD43, is a potential biomarker for the diagnosis of acute leukemia. Although qualitative assays for detecting leukemia-specific CD43 exist, there is a need to develop quantitative assays for the same. Here, we developed two novel monoclonal antibodies (mAbs), 2C8 and 8E10, recognizing different epitopes on CD43. These clones are capable of pairing with YG5, another mAb against JL1 epitope, because they were selectively obtained using sandwich ELISA. Antigens recognized by 2C8 and 8E10 were confirmed as CD43 by western blotting using the CD43-hFC recombinant protein. When expression on various leukemic cell lines was investigated, 2C8 and 8E10 displayed a disparity in the distribution of the epitope. Enzyme assays revealed that these mAbs recognized a sialic acid-dependent epitope on CD43. Using normal thymus and lymph node paraffin-embedded tissues, we confirmed a difference in the epitopes recognized by the two mAbs that was predicted based on the maturity of the cells in the tissue. In summary, we developed and characterized two mAbs, 2C8 and 8E10, which can be used with YG5 in a sandwich ELISA for detecting leukemia-specific CD43.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.45 no.3
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• pp.299-306
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• 2019

Ginseng berry (GB) contains Ginsenoside Re and has anti-inflammatory and anti-wrinkle properties. In this study, TLC fractions 1, 2, and 4 of the ginseng berry amino acid complex were identified and analyzed by HPLC. And identified a peptide (AP-1) by LC/MASS analysis of fraction 1. The anti-inflammatory activity was confirmed by investigating the inhibitory effect of AP-1 on NO production. In addition, collagen synthesis using procollagen type I C-peptide (PIP) ELISA kit was 50% higher effective than that of the control group. From these results, the peptide isolated from ginseng berry amino acid complex is considered to have anti-inflammatory and anti-wrinkle effect, and may be useful as an anti-inflammatory and anti-aging cosmetic raw material.