• 한국동물위생학회지
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• 제34권1호
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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.

• Parasites, Hosts and Diseases
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• 제58권1호
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• pp.1-5
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• 2020

Sarcocystosis was diagnosed worldwide by serodiagnostic tests utilising the whole parasite, for which the protozoa were maintained in vitro are more costly. In this study, antigenicity of Sarcocystis falcatula recombinant protein (rSfSAG4) was investigated towards the local communities of Pangkor and Tioman Islands and its seroprevalence was surveyed in these islands. A total of 348 human sera were tested using rSfSAG4 by Western blot and ELISA. High prevalence of sarcocystosis was observed in Tioman Island (80.6%) than in Pangkor Island (50.0%) by Western blot. In ELISA, the seroprevalence observed in Tioman Island was 45.9%, whereas in Pangkor Island 63.0%. In other parasitic infections, the prevalence was 34.0% by Western blot and 46.0% by ELISA. In healthy control group, 7% by Western blot and 8% by ELISA showed positivity to rSfSAG4. It is suggested SfSAG4 is a candidate antigen to measure seroprevalence of sarcocystosis.

• Parasites, Hosts and Diseases
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• 제57권1호
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• pp.61-67
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• 2019

Cystic echinococcosis (CE) in sheep is a hazardous zoonotic parasitic disease that is caused by Echinococcus granulosus (Eg). At present, serological test is an important diagnostic method for Eg infection in domestic animals. Here, a fusion protein Eg mefAg-1 harboring 8 dominant B-cell epitopes of Eg such as antigen B, tetraspanin 1, tetraspanin 6, reticulon and Eg95 was produced in E. coli and evaluated for CE in sheep by indirect ELISA. Eg mefAg-1 showed in ELISA a high sensitivity (93.41%) and specificity (99.31%), with a coincidence rate of 97.02%. Overall, it is suggested that the Eg mefAg-1 could be a potential antigen candidate for CE serodiagnosis in sheep.

• Parasites, Hosts and Diseases
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• 제52권2호
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• pp.137-142
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• 2014

Serologic tests are widely accepted for diagnosing Toxoplasma gondii but purification and standardization of antigen needs to be improved. Recently, surface tachyzoite and bradyzoite antigens have become more attractive for this purpose. In this study, diagnostic usefulness of 3 recombinant antigens (SAG1, SAG2, and SAG3) were evaluated, and their efficacy was compared with the available commercial ELISA. The recombinant plasmids were transformed to JM109 strain of Escherichia coli, and the recombinants were expressed and purified. Recombinant SAG1, SAG2, and SAG3 antigens were evaluated using different groups of sera in an ELISA system, and the results were compared to those of a commercial IgG and IgM ELISA kit. The sensitivity and specificity of recombinant surface antigens for detection of anti-Toxoplasma IgG in comparison with commercially available ELISA were as follows: SAG1 (93.6% and 92.9%), SAG2 (100.0% and 89.4%), and SAG3 (95.4% and 91.2%), respectively. A high degree of agreement (96.9%) was observed between recombinant SAG2 and commercial ELISA in terms of detecting IgG anti-Toxoplasma antibodies. P22 had the best performance in detecting anti-Toxoplasma IgM in comparison with the other 2 recombinant antigens. Recombinant SAG1, SAG2, and SAG3 could all be used for diagnosis of IgG-specific antibodies against T. gondii.

• Parasites, Hosts and Diseases
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• 제30권3호
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• pp.191-200
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• 1992

한국산 유혈목이에서 스파르가눔 충체를 수집하고, 이들 충체의 추출액에서 ion-exchange chromatography와 affinity chromatography를 실시하여 cysteine proteinase를 순수 정제하였다. 경제된 효소의 최적 pH는 5.5이었고, 최적 mole 농도는 0.IM (0.1M sodium acetate, pH5.5) 이었다. 정제된 대소는 thiol-dependent이고, $4^{\circ}C$에서 pH 5.0일 때 24시간 동안 안전성을 보였다. 효소의 환성도는 저분자 합성기질인 CBZ-phe-arg-AFC에 대 해 활성이 높았다. 정제된 효소는 척추동물의 산성 cysteine proteinase의 억제인자에 감수성을 보였다. UItrogel AcA54 column chromatography로 정제된 cysteine proteinase의 분자량을 측정한 결과 28,000 dalton이었다. 정제된 효소는 collagen type I과 hemoglobin을 분해하였다. Immunoblot한 결과 정제된 효소는 스파르가눔증 환자의 혈청과 반응하였다. 이상의 결과에서 스파르가눔의 cysteine proteinase는숙주 체내이동, 조직침수성 및 영양소 섭취에 관여할 것이라 추정되며, 정제된 효소는 스파르가눔 현중의 혈청학적 진단에 이용될 수 있을 것으로 생각된다.

• Parasites, Hosts and Diseases
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• 제39권2호
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• pp.171-176
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• 2001

Western blot analysis was performed to diagnose vivax malaria using stage-specific recombinant antigens. Genomic DNA from the whole blood of a malaria patient was used as templates to amplify the coding regions for the antigenic domains of circumsporozoite protein (CSP-1), meroxoite surface protein (MSP-1), apical merozoite antigen (AMA- 1), serine repeat antigen (SERA), and exported antigen (EXP- 1) of Plasmodium vivax. Each amplified DNA fragment was inserted into a pGEX-4T plasmid to induce the expression of GST fusion protein in Escherichia coli by IPTG. The bacterial cell extracts were separated on 10% SDS-PAGE followed by western blot analysis with patient sera which was confirmed by blood smear examination. When applied with patient sera, 147 (91.9%) out of 160 vivax malaria, 12 (92.3%) out of 13 falciparum malaria, and all 9 vivax/falciparum mixed malaria reacted with at least one antigen, while no reactions occurred with 20 normal uninfected sera. In the case of vivax malaria, CSP-1 reacted with 128 (80.0%) sera, MSP-1 with 102 (63.8%), AMA-1 with 128 (80.0%), SERA with 115 (71.9%), and EXP-1 with 89 (55.6%), respectively. We obtained higher detection rates when using S antigens (91.9%) rather than using each antigen solely (55.6 - 80%), a combination of 2 (76.3 - 87.5%), 3 (85.6 - 90.6%), or 4 antigens (89.4 - 91.3%). This method can be applied to serological diagnosis, mass screening in endemic regions, or safety test in transfusion of prevalent vivax malaria.

• Parasites, Hosts and Diseases
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• 제51권6호
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• pp.763-766
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• 2013

A synthetic peptide was prepared based on the antigenic region of Paragonimus westermani pre-procathepsin L, and its applicability for immunodiagnosis for human paragonimiasis (due to Paragonimus heterotremus) was tested using an ELISA to detect IgG4 antibodies in the sera of patients. Sera from other helminthiases, tuberculosis, and healthy volunteers were used as the references. This peptide-based assay system gave sensitivity, specificity, accuracy, and positive and negative predictive values of 100%, 94.6%, 96.2%, 100%, and 88.9%, respectively. Cross reactivity was frequently seen against the sera of fascioliasis (75%) and hookworm infections (50%). Since differential diagnosis between paragonimiasis and fascioliasis can be easily done by clinical presentation and fascioliasis serology, this cross reaction is not a serious problem. Sera from patients with other parasitoses (0-25%) rarely responded to this synthetic antigen. This synthetic peptide antigen seems to be useful for development of a standardized diagnostic system for paragonimiasis.

• Parasites, Hosts and Diseases
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• 제32권4호
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• pp.231-242
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• 1994

자연 감염된 가재에서 폐흡충의 피낭유충을 분리하고 개에 경구 감염시켜 성충을 얻었다. 폐흡충 성충의 조효소를 ion-exchange chromatography, affinity chromatography와 gel filtration chromatoglaphy를 실시하여 cysteine proteinase를 순수 정제하였다. 이들 효소의 생화학적 특성과 분해능을 관찰하였으며. 효소면역전기영동이적법을 이용하여 순수 정제한 효소의 항원성을 관찰하였다. 정제된 효소는 저분자 합성기질인 CBZ-arg-arg-AFC 보다 CBZ-phe-arg-AFC에서 높은 활성을 보였으며. 이들 효소는 thiol-dependent이었다. 정제된 효소 및 조효소의 최적 pH는 5.5이었고. 최적 mole 농도는 0.1 M(0.1 M sodium citrate, pH 5.5)이었고, 이들 효소는 $4^{\circ}C$에서 48시간 동안 80%의 안정성을 보였다 정제된 효소의 native 분자량은 20.000 dalton이었고, SDS- PAGE상에 나타난 분자량은 17,500 dalton이었다 정제된 효소는 cysteine proteinase 특이 억제 인자인 E-64, lodoacetic acid, NEM에 의해 활성이 완전히 억제되었으며, serine proteinase, aspartic proteinase 및 metallo proteinase 특이 억제인자에 의해 활성이 억제되지 않았다. 정제된 효소는 collagen(Type I)과 hemoglobin을 분해하였고, 효소면역전기영동이적법으로 정제된 효소의 항원성을 확인하였다.

• Parasites, Hosts and Diseases
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• 제51권5호
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• pp.503-510
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• 2013

Toxoplasma gondii is an apicomplexan parasite with a broad host range of most warm-blooded mammals including humans, of which one-thirds of the human population has been infected worldwide which can cause congenital defects, abortion, and neonatal complications. Here, we developed a rapid diagnostic test (RDT) for T. gondii infection. Antigenic N-terminal half of the major surface antigen (SAG1) was linked with intrinsically unstructured domain (IUD) of dense granule protein 2 (GRA2). The recombinant GST-GRA2-SAG1A protein was successfully expressed and purified as 51 kDa of molecular weight. Furthermore, antigenicity and solubility of the rGST-GRA2-SAG1A protein were significantly increased. The overall specificity and sensitivity of GST-GRA2-SAG1A loaded RDT (TgRDT) were estimated as 100% and 97.1% by comparing with ELISA result which uses T. gondii whole cell lysates as the antigen. The TgRDT tested with Uganda people sera for field trial and showed 31.9% of seroprevalence against T. gondii antibody. The TgRDT is proved to be a kit for rapid and easy to use with high accuracy, which would be a suitable serodiagnostic tool for toxoplasmosis.

• Parasites, Hosts and Diseases
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• 제39권1호
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• pp.57-66
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• 2001

In the course of immunoscreening of Clonorchis sinensis cDNA library, a cDNA CsRP12 containing a tandem repeat was isolated. The cDNA CsRP 12 encodes two putative peptides of open reading frames (ORFs) 1 and 2 (CsRP12-1 and -2). The repetitive region is composed of 15 repeats of 10 amino acids. Of the two putative peptides, CsRP12-1 was proline-rich and found to have homologues in several organisms. Recombinant proteins of the putative peptides were bacterially produced and purified by an affinity chromatography Recombinant CsRP12-1 protein was recognized by sera of clonorchiasis patients and experimental rabbits, but recombinant CsRP 12-2 was not. One of the putative peptide, CsRP12-1, is designated CsPRA, proline-rich antigen of C. sinensis. Both the C-termini of CsRP12-1 and -2 were bacterially produced and analysed to show no antigenicity. Recombinant CsPRA protein showed high sensitivity and specificity. In experimental rabbits, IgG antibodies to CsPRA was produced between 4 and 8 weeks after the infection and decreased thereafter over one you. These results indicate that CsPRA is equivalent to a natural protein and a useful antigenic protein for serodiagnosis of human clonorchiasis.