• Title/Summary/Keyword: indirect enzyme-linked immunosorbent assay

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Prevalence and Genetic Characteristics of Japanese Encephalitis Virus among Mosquitoes and Pigs in Hunan Province, China from 2019 to 2021

  • Tang, Qiwu;Deng, Zaofu;Tan, Shengguo;Song, Guo;Zhang, Hai;Ge, Lingrui
    • Journal of Microbiology and Biotechnology
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    • v.32 no.9
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    • pp.1120-1125
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    • 2022
  • Japanese encephalitis virus (JEV), the causative agent of Japanese encephalitis (JE), is an importantly zoonotic, vector-borne virus widely prevalent in Asia. Although JE has been well controlled in China, its prevalence remains a huge threat to the pig industry as well as human health. Herein, we report on our molecular and serological investigations of JEV among pigs from different regions in Hunan Province of China from 2019 to 2021. Collectively, 19.27% (583/3026, 95% Confidential Interval (CI) 17.86-20.68) of sampled pigs were positive for JEV IgG antibody as revealed by indirect enzyme-linked immunosorbent assay, and the seroprevalence of JEV among pigs was significantly associated with the development stage and breeding scale (p < 0.01). Meanwhile, 10.99% (42/382, 95% CI 7.86-14.13) of tissue samples of pigs with suspected clinical symptoms of JE and 23.44% (15/64, 95% CI 13.06-33.82) of mosquito batches were JEV-positive via reverse polymerase chain reaction. In addition, the complete E gene sequences of 14 JEV strains identified in this study were amplified and sequenced. Phylogenetic analysis showed that all 14 JEV strains belonged to genotype I-b and displayed a distinct genetic relationship to the present JEV vaccine strain (SA14-14-2). In conclusion, our results revealed not only the severe prevalence of JEV in Hunan Province, but also that JEV I-b might be the predominant genotype in Hunan Province, suggesting therefore that effective measures for JE control are urgently needed.

Association of farmers' knowledge, attitude and practices with bovine brucellosis seroprevalence in Myanmar

  • Su Su Hlaing;Satoko Kubota;Kohei Makita;Ye Tun Win;Hnin Thidar Myint;Hiroichi Kono
    • Animal Bioscience
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    • v.37 no.3
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    • pp.547-554
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    • 2024
  • Objective: This study aimed to identify the relationship between bovine brucellosis prevalence, farmers' knowledge, attitude, practice (KAP), and social factors on migratory draft cattle and smallholder dairy farms in the central dry zone of Myanmar. Methods: This cross-sectional study was conducted on 54 migratory and 38 dairy cattle farms between August 2020 and February 2021. A structured questionnaire was used to identify farmers' behaviors. Bulk milk was sampled and tested using indirect enzyme-linked immunosorbent assay (I-ELISA). STATA 17 was used for all the analyses. Results: Migratory cattle farms had a higher farm level brucellosis prevalence (14.8%) than dairy farms (2.6%; χ2 = 3.75; df = 1; p = 0.05). Only 2.8% of the farmers had knowledge about brucellosis, while 39.1% and 41.6% had attitudes and farm practices with respect to brucellosis, respectively in the study area. Socio-economic attribute of training in animal husbandry (p<0.01), raising system (p<0.01), practice of separating the aborted cow (p<0.01) were negatively associated to brucellosis. The overall farm level brucellosis prevalence was strongly associated with cattle herd size (p = 0.01), free movement grazing practices (p<0.01), practice of self-removal of placental debris without using personal protective equipment (p<0.01) and farmers' attitudes towards eating cow placenta debris (p<0.01). Conclusion: Farmers had little knowledge of brucellosis. Attitudes and practices differed significantly between migratory and dairy farmers. Training and extension programs are necessary to make farmers aware of their KAP situation since livestock migration and the custom of eating cow placental debris contribute to the spread of brucellosis. Persistent efforts are required to reduce the adverse effects of brucellosis. Therefore, the study suggests that a feasible control intervention and public awareness campaigns need to be conducted regarding methods of preventing human exposure to brucellosis.

Application of Oral Fluid Sample to Monitor Porcine circovirus-2 Infection in Pig Farms (구강액을 이용한 양돈장의 Porcine circovirus-2 감염에 대한 모니터링)

  • Kim, Won-Il
    • Journal of Veterinary Clinics
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    • v.27 no.6
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    • pp.704-712
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    • 2010
  • Porcine circovirus-2 (PCV2) has been implicated in many clinical diseases/syndromes that are now referred to as PCV-associated diseases (PCVAD). Due to significant economic losses caused by PCVAD, many swine operations have launched extensive monitoring programs for PCV2. Traditional serum sampling is, however, rather expensive and laborious, hampering effective large scale pathogen surveillance. A field-based longitudinal study was conducted to assess the utility of pen-based oral fluid sample as an alternative to serum for herd PCV2 testing. Six pens (25 pigs/pen) at each of 3 different sites were used in the study. One oral fluid and 5 random serum samples per pen were collected at 3, 5, 8, 12, and 16 weeks of age, and the sera were pooled by pen for testing. All samples were tested for PCV2 by real-time PCR and for antibodies by indirect fluorescent antibody test (for both anti-PCV2 IgG and IgA) and 3 ELISA assays (blocking ELISA, indirect ELISA, and IgG/IgM sandwich ELISA). PCV2 DNA was detected in oral fluid samples sporadically until 8 weeks and in all pens at 16 weeks. PCV2-specific IgG was detected in oral fluid samples at 3 weeks and persisted until 5 to 8 weeks in all sites. Anti-PCV2 IgG and IgA were detectable in oral fluid samples collected at 16 weeks from all of the pens at 1 site. The detection of PCV2 and anti-PCV2 antibody in oral fluid samples correlated positively with results on pooled sera, suggesting that oral fluids can be a cost-effective alternative to serum for herd monitoring of PCV2 infection.

Identification of a conservative site in the African swine fever virus p54 protein and its preliminary application in a serological assay

  • Xu, Lingyu;Cao, Chenfu;Yang, Zhiyi;Jia, Weixin
    • Journal of Veterinary Science
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    • v.23 no.4
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    • pp.55.1-55.12
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    • 2022
  • Background: ASF was first reported in Kenya in 1910 in 1921. In China, ASF spread to 31 provinces including Henan and Jiangsu within six months after it was first reported on August 3, 2018. The epidemic almost affected the whole China, causing direct economic losses of tens of billions of yuan. Cause great loss to our pig industry. As ELISA is cheap and easy to operate, OIE regards it as the preferred serological method for ASF detection. P54 protein has good antigenicity and is an ideal antigen for detection. Objective: To identify a conservative site in the African swine fever virus (ASFV) p54 protein and perform a Cloth-enzyme-linked immunosorbent assay (ELISA) for detecting the ASFV antibody in order to reduce risks posed by using the live virus in diagnostic assays. Method: We used bioinformatics methods to predict the antigen epitope of the ASFV p54 protein in combination with the antigenic index and artificially synthesized the predicted antigen epitope peptides. Using ASFV-positive serum and specific monoclonal antibodies (mAbs), we performed indirect ELISA and blocking ELISA to verify the immunological properties of the predicted epitope polypeptide. Results: The results of our prediction revealed that the possible antigen epitope regions were A23-29, A36-45, A72-94, A114-120, A124-130, and A137-150. The indirect ELISA showed that the peptides A23-29, A36-45, A72-94, A114-120, and A137-150 have good antigenicity. Moreover, the A36-45 polypeptide can react specifically with the mAb secreted by hybridoma cells, and its binding site contains a minimum number of essential amino acids in the sequence 37DIQFINPY44. Conclusions: Our study confirmed a conservative antigenic site in the ASFV p54 protein and its amino acid sequence. A competitive ELISA method for detecting ASFV antibodies was established based on recombinant p54 and matching mAb. Moreover, testing the protein sequence alignment verified that the method can theoretically detect antibodies produced by pigs affected by nearly all ASFVs worldwide.

LEVELS OF TNF-α,-β, IL-1β, TGF-β1 AND THEIR RELATIONSHIP WITH THE PRESENCE OF SPECIFIC BLACK PIGMENTED BACTERIA IN PERIAPICAL AND PULPAL DISEASES (치근단 및 치수병변 환자에서의 TNF-α와 β, IL-1β 및 TGF-β1의 수준과 근관내 특정 black pigmented bacteria와의 연관성에 관한 연구)

  • Byun, Ho-Young;Lim, Sung-Sam;Park, Dong-Sung
    • Restorative Dentistry and Endodontics
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    • v.24 no.1
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    • pp.1-12
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    • 1999
  • Bacterial infection of the pulp results in the development of a periapical lesion with the concomitant resorption of periapical bone. The cytokines are believed to play an important role in this matter. The purpose of this study was to find the relationship among the presence of black pigmented bacteria, the levels of cytokines(TNF-${\alpha}$, -${\beta}$, IL-$1{\beta}$, and TGF-${\beta}1$), and the amount of bone resorption in periapical and pulpal diseases. For the purpose, the patients were grouped into chronic apical pathosis, acute apical pathosis, acute pulpitis, and a healthy control group. Root canal samples were taken from periapical tissue exudates during routine endodontic treatment, and the venous blood was taken from each patients. The samples were processed to measure local and systemic levels of the cytokines using enzyme linked immunosorbent assay(ELISA). Bacterial content of Porphyromonas endodontalis, Porphyromonas gingivalis, and Prevotella nigrescens were measured by indirect immunofluorescence method and the size of the periapical lesions were measured from the radiographs. The following results were obtained: 1. The levels of bone resorptive cytokines(TNF-${\alpha}$, TNF-${\beta}$, and IL-$1{\beta}$) in exudates from acute and chronic apical pathoses were significantly higher than those from acute pulpitis and the normal pulps(p<0.05). 2. IL-$1{\beta}$ were the highest among the bone resorptive cytokines in apical pathoses. However, no statistical difference between acute and chronic lesions were found(p>0.05). 3. The levels of TGF-${\beta}1$ in exudates from acute pulpitis and chronic apical pathoses were significantly higher than those from acute apical pathoses and the normal pulps(p<0.05). However, there were no significant correlations among the levels of bone resorptive cytokines. 4. The levels of TNF-${\beta}$ in serum were significantly higher than those from the exudates while serum TGF-${\beta}1$ concentrations were significantly lower(p<0.05). 5. Exudates from the canals in which the P. nigrescens were detected showed significantly higher levels of IL-$1{\beta}$ than those from the canals without the microorganism(p<0.05). 6. There were no significant correlations among the levels of the cytokines, the amount of bone destruction, and the presence of acute and chronic symptoms(p>0.05).

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Production of A Monoclonal Antibody (MAb) Against a Thermal Stable-Soluble Protein in Mackerel and Confirmation of the Properties for the MAb (고등어 어육 중 열안정성 단백질에 특이한 단클론성 항체 개발과 특성 확인)

  • Lee, Jeong-Eun;Kim, Jeong-Sook;Chung, Duck-Hwa;Shim, Won-Bo
    • Journal of Food Hygiene and Safety
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    • v.32 no.1
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    • pp.75-81
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    • 2017
  • For people who have a food allergy the only way to manage the allergy is to avoid the food allergen. The mackerel is one of the major food allergens, but no immunoassay for the rapid and simple detection of mackerel has been reported. The objectives of this study are to develop and characterize monoclonal antibodies (MAbs) specific to mackerel using thermal stable-soluble proteins (TSSP) as an immunogen and to characterize the MAbs by indirect enzyme-linked immunosorbent assay (iELISA). The mice immunized with mackerel TSSP and showing high titer were used for cell fusion and cloning. The characterization of MAbs produced from hybridoma cells obtained was confirmed by indirect ELISA and western blot. Four MAbs were confirmed to be specific to mackerel without cross-reaction to other marine products and livestock products in the both methods. The iELISA and western blot based on the MAbs can sensitively detect 1% mackerel protein in other marine products. These results support that immunochemical methods based on the MAb produced could be used as rapid means to detect low levels of mackerel and to identify mackerel adulterated in food.

Evaluation of the antibodies against Pseudomonas tolaasii and Pseudomonas agarici for Immunoassays and Its Application (항 Pseudomonas tolaasii 및 Pseudomonas agarici 항체의 면역측정법을 위한 평가와 그 이용)

  • Jeon, Nak-Beom;Lee, Hyang-Burm;Shon, Dong-Hwa;Yu, Seung Hun
    • Research in Plant Disease
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    • v.9 no.2
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    • pp.94-98
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    • 2003
  • To produce antibodies against Pseudomonas tolaasii and P. agarici, lyophilized P. tolaasii and P. agarici ($5{\times}10^7$ cfu/ml) and Freund, s adjuvant were immunized into rabbits 4 times. The specificity and sensitivity of the antibodies were evaluated by immunodiffusion test and indirect enzyme-linked immunosorbent assay (id ELISA). The ${\alpha}$-P. tolaasii antibody was very specific only against P. tolaasii, while ${\alpha}$-P. agarici antibody was not specific and showed a high cross reactivity toward P. tolaasii with detection limit concentration of $2{\times}10^3$ cfu/ml. However, the cross reactivities of ${\alpha}$-P. agarici antibody toward the related species including P. reactans were very low. Our results showed that ${\alpha}$-P. tolaasii and ${\alpha}$-P. agarici antibodies against P. tolaasii and P. agarici, respectively, might be useful for rapid and simple detection of the causal agents of bacterial brown and yellow blotches in cultivated oyster mushrooms.

Study on the Changes in Allergen and Allergenicity Originated from Shrimp by Physical Treatments (물리적 처리에 의한 새우유래 Allergen 및 Allergenicity 변화)

  • Kim, Seong-Mi;Park, Jin-Gyu;Kim, Koth-Bong-Woo-Ri;Lee, Ju-Woon;Byun, Myung-Woo;Park, Sun-Mee;Ahn, Dong-Hyun
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.35 no.8
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    • pp.990-996
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    • 2006
  • This research was conducted to evaluate the changes in allergenicity of shrimp by physical treatments using competitive indirect enzyme-linked immunosorbent assay (Ci-ELISA). Shrimp was subjected to physical treatments such as high hydrostatic pressure (HHP), sonication, autoclave and microwave. Heat-stable protein (HSP) purified from raw shrimp was used as a major allergen. The binding ability of monoclonal IgG and shrimp-allergic patients' IgE to HSP treated with HHP decreased, increasing the pressure up to 400 MPa. Especially, it became less than 50% at 400 MPa. The binding ability of mAb to HSP treated with sonication (10, 20, 30 and 60 min) decreased with the treated time. Especially, it became less than 60% with the treatment for 60 min. The allergenicity change of HSP treated with autoclave and microwave little decreased. The binding ability of mAb to HSP during the treatment for 20 min became more than 70%. The results suggest that allergenicity of HSP in raw shrimp be more easily lost by HHP or sonication treatment than by autoclave or microwave treatment.

Effect of Xenogeneic Substances on the Glycan Profiles and Electrophysiological Properties of Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes

  • Yong Guk, Kim;Jun Ho Yun;Ji Won Park;Dabin Seong;Su-hae Lee;Ki Dae Park;Hyang-Ae Lee;Misun Park
    • International Journal of Stem Cells
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    • v.16 no.3
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    • pp.281-292
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    • 2023
  • Background and Objectives: Human induced pluripotent stem cell (hiPSC)-derived cardiomyocyte (CM) hold great promise as a cellular source of CM for cardiac function restoration in ischemic heart disease. However, the use of animal-derived xenogeneic substances during the biomanufacturing of hiPSC-CM can induce inadvertent immune responses or chronic inflammation, followed by tumorigenicity. In this study, we aimed to reveal the effects of xenogeneic substances on the functional properties and potential immunogenicity of hiPSC-CM during differentiation, demonstrating the quality and safety of hiPSC-based cell therapy. Methods and Results: We successfully generated hiPSC-CM in the presence and absence of xenogeneic substances (xeno-containing (XC) and xeno-free (XF) conditions, respectively), and compared their characteristics, including the contractile functions and glycan profiles. Compared to XC-hiPSC-CM, XF-hiPSC-CM showed early onset of myocyte contractile beating and maturation, with a high expression of cardiac lineage-specific genes (ACTC1, TNNT2, and RYR2) by using MEA and RT-qPCR. We quantified N-glycolylneuraminic acid (Neu5Gc), a xenogeneic sialic acid, in hiPSC-CM using an indirect enzyme-linked immunosorbent assay and liquid chromatography-multiple reaction monitoring-mass spectrometry. Neu5Gc was incorporated into the glycans of hiPSC-CM during xeno-containing differentiation, whereas it was barely detected in XF-hiPSC-CM. Conclusions: To the best of our knowledge, this is the first study to show that the electrophysiological function and glycan profiles of hiPSC-CM can be affected by the presence of xenogeneic substances during their differentiation and maturation. To ensure quality control and safety in hiPSC-based cell therapy, xenogeneic substances should be excluded from the biomanufacturing process.

Effect of Digestive Enzymes on the Allergenicity of Autoclaved Market Pork Sausages (가압가열 처리한 시판 돈육 소시지의 항원성에 미치는 소화효소의 영향)

  • Kim, Seo-Jin;Kim, Koth-Bong-Woo-Ri;Song, Eu-Jin;Lee, So-Young;Yoon, So-Young;Lee, So-Jeong;Lee, Chung-Jo;Ahn, Dong-Hyun
    • Food Science of Animal Resources
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    • v.29 no.2
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    • pp.238-244
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    • 2009
  • Food allergy is a serious nutritional problem in both children and adults. Therefore, food allergenicity reduction methods are greatly needed. The allergenicity is altered by various manufacturing processes, and the digestibility of food proteins can be affected by food processing. This study was conducted to investigate the effect of in-vitro digestibility on the allergenicity of autoclaved market pork sausages using pepsin (30min) and trypsin (5, 30, 60, 90, and 120min). The binding ability of the porcine serum albumin (PSA) from sausages A and B significantly decreased by about 30 and 23%, respectively, after autoclave treatment (121; 5, 10, and 30 min). After the pepsin and trypsin treatments, the binding ability of products A and B at 30 min decreased. These competitive indirect enzyme-linked immunosorbent assay (ci-ELISA) results corresponded well with the sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting results. The results demonstrated that the allergenicity of pork sausages considerably decreased after autoclave treatment, and were also maintained or decreased after enzyme treatment. Accordingly, autoclave treatment represents a promising processing technology for the reduction of the allergenicity of diverse food products.