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Máčala J, Makhneva E, Hlaváček A, Kopecký M, Gorris HH, Skládal P, Farka Z. Upconversion Nanoparticle-Based Dot-Blot Immunoassay for Quantitative Biomarker Detection. Anal Chem 2024; 96:10237-10245. [PMID: 38870418 PMCID: PMC11209662 DOI: 10.1021/acs.analchem.4c00837] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2024] [Revised: 05/14/2024] [Accepted: 06/03/2024] [Indexed: 06/15/2024]
Abstract
Dot-blot immunoassays are widely used for the user-friendly detection of clinical biomarkers. However, the majority of dot-blot assays have only limited sensitivity and are only used for qualitative or semiquantitative analysis. To overcome this limitation, we have employed labels based on photon-upconversion nanoparticles (UCNPs) that exhibit anti-Stokes luminescence and can be detected without optical background interference. First, the dot-blot immunoassay on a nitrocellulose membrane was optimized for the quantitative analysis of human serum albumin (HSA), resulting in a limit of detection (LOD) of 0.19 ng/mL and a signal-to-background ratio (S/B) of 722. Commercial quantum dots were used as a reference label, reaching the LOD of 4.32 ng/mL and the S/B of 3, clearly indicating the advantages of UCNPs. In addition, the potential of UCNP-based dot-blot for real sample analysis was confirmed by analyzing spiked urine samples, reaching the LOD of 0.24 ng/mL and recovery rates from 79 to 123%. Furthermore, we demonstrated the versatility and robustness of the assay by adapting it to the detection of two other clinically relevant biomarkers, prostate-specific antigen (PSA) and cardiac troponin (cTn), reaching the LODs in spiked serum of 9.4 pg/mL and 0.62 ng/mL for PSA and cTn, respectively. Finally, clinical samples of patients examined for prostate cancer were analyzed, achieving a strong correlation with the reference electrochemiluminescence immunoassay (recovery rates from 89 to 117%). The achieved results demonstrate that UCNPs are highly sensitive labels that enable the development of dot-blot immunoassays for quantitative analysis of low-abundance biomarkers.
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Affiliation(s)
- Jakub Máčala
- Department
of Biochemistry, Faculty of Science, Masaryk
University, Kamenice 5, 625 00 Brno, Czech Republic
| | - Ekaterina Makhneva
- Department
of Biochemistry, Faculty of Science, Masaryk
University, Kamenice 5, 625 00 Brno, Czech Republic
| | - Antonín Hlaváček
- Institute
of Analytical Chemistry of the Czech Academy of Sciences, Veveří 97, 602 00 Brno, Czech Republic
| | - Martin Kopecký
- Department
of Biochemistry, Faculty of Science, Masaryk
University, Kamenice 5, 625 00 Brno, Czech Republic
| | - Hans H. Gorris
- Department
of Biochemistry, Faculty of Science, Masaryk
University, Kamenice 5, 625 00 Brno, Czech Republic
| | - Petr Skládal
- Department
of Biochemistry, Faculty of Science, Masaryk
University, Kamenice 5, 625 00 Brno, Czech Republic
| | - Zdeněk Farka
- Department
of Biochemistry, Faculty of Science, Masaryk
University, Kamenice 5, 625 00 Brno, Czech Republic
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Yadav V, Rafiqi SI, Yadav A, Kushwaha A, Godara R, Katoch R, Panadero-Fontán R. Dot-ELISA based on recombinant Hypodermin C of Przhevalskiana silenus for field diagnosis of goat warble fly infestation. Parasite Immunol 2023; 45:e13007. [PMID: 37524537 DOI: 10.1111/pim.13007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Revised: 07/16/2023] [Accepted: 07/18/2023] [Indexed: 08/02/2023]
Abstract
Goat warble fly infestation (GWFI) is an economically important myiasis caused by larvae of Przhevalskiana silenus (Diptera, Oestridae), prevalent in countries of the Mediterranean Basin and Indian subcontinent. GWFI is characterized by the presence of subcutaneous warbles at the lumbar and sacral region of dorsum in the infested animal. The early larval instars (L1 and L2) remain inaccessible to physical detection due to their small size and subcutaneous presence thus causing hindrance in the diagnosis. The objective of present study was to develop a field applicable early diagnostic intervention for GWFI monitoring and prophylactic management for effective control of the disease. Recombinant Hypodermin C (rHyC) antigen of P. silenus was expressed in Escherichia coli. The purified protein was used for optimizing dot-ELISA in a checkerboard titration using goat warble fly infested serum as known positive. The optimized assay was further tested for lower temperature (18°C) and incubation time (30 min). The optimized assay was assessed for inter-rater reliability and field samples. The optimized conditions require 188 ng of protein/dot, 1:800 dilution of serum sample, 1:4000 dilution of anti-goat IgG conjugate and 5% skim milk powder in phosphate buffer saline as blocking buffer. The assay was found to have a diagnostic sensitivity and specificity of 97.3% and 95.8%, respectively. The inter-rater reliability of dot ELISA with rHyC indirect ELISA was found to be almost perfect with a Cohen's kappa index of 0.973. Further testing at ambient temperature (18°C) and shorter incubation steps (30 min) supported suitability of the assay for field diagnosis of GWFI. The present study provides the first report of a sensitive and specific dot-ELISA for early diagnosis of GWFI which is rapid and cost effective. The test may provide an effective field applicable tool for sustainable control of GWFI.
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Affiliation(s)
- Vikas Yadav
- Division of Veterinary Parasitology, Faculty of Veterinary Sciences and Animal Husbandry, Sher-e-Kashmir University of Agricultural Sciences and Technology of Jammu, R. S. Pura, UT of Jammu and Kashmir, India
| | - Shafiya Imtiaz Rafiqi
- Division of Veterinary Parasitology, Faculty of Veterinary Sciences and Animal Husbandry, Sher-e-Kashmir University of Agricultural Sciences and Technology of Jammu, R. S. Pura, UT of Jammu and Kashmir, India
| | - Anish Yadav
- Division of Veterinary Parasitology, Faculty of Veterinary Sciences and Animal Husbandry, Sher-e-Kashmir University of Agricultural Sciences and Technology of Jammu, R. S. Pura, UT of Jammu and Kashmir, India
| | - Anand Kushwaha
- Division of Veterinary Parasitology, Faculty of Veterinary Sciences and Animal Husbandry, Sher-e-Kashmir University of Agricultural Sciences and Technology of Jammu, R. S. Pura, UT of Jammu and Kashmir, India
| | - Rajesh Godara
- Division of Veterinary Parasitology, Faculty of Veterinary Sciences and Animal Husbandry, Sher-e-Kashmir University of Agricultural Sciences and Technology of Jammu, R. S. Pura, UT of Jammu and Kashmir, India
| | - Rajesh Katoch
- Division of Veterinary Parasitology, Faculty of Veterinary Sciences and Animal Husbandry, Sher-e-Kashmir University of Agricultural Sciences and Technology of Jammu, R. S. Pura, UT of Jammu and Kashmir, India
| | - Rosario Panadero-Fontán
- INVESAGA Group, Department of Animal Pathology, Universidade de Santiago de Compostela, Lugo, Spain
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Márquez-Mauricio A, Caballero-Ortega H, Gómez-Chávez F. Congenital Toxoplasmosis Diagnosis: Current Approaches and New Insights. Acta Parasitol 2023; 68:473-480. [PMID: 37368128 DOI: 10.1007/s11686-023-00693-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Accepted: 06/07/2023] [Indexed: 06/28/2023]
Abstract
PURPOSE The aim of this study is to describe and discuss current disadvantages in congenital toxoplasmosis (CT) diagnosis, and what can be improved or changed through new perspectives and technological advances. METHODS We used Pubmed, Cochrane, and EBSCO databases to research publications from 10 years to date describing current diagnostic methods for CT. The keywords used for this Mini-Review were Toxoplasma gondii, congenital toxoplasmosis, diagnosis, and prospects using Boolean operators such as AND, OR, identifying scientific publications highlighting the importance of implementing new diagnostic methods. RESULTS Current diagnosis methods have several disadvantages, i.e., time-consuming, low sensitivity or specificity, and non-cost effective, that bring up the necessity of improving or developing new approaches. Recombinant proteins can help improve specificity by generating tests that use circulating strains in a specific geographical region, SAG1 and BAG1, as they are expressed during a particular stage of the disease (acute or chronic, respectively), for its use in serological diagnoses, such as capture ELISA and immunochromatography. Point of Care (POC) tests are methods performed at the patient care site, which leads to rapid patient treatment; despite the advantages, several improvements and perspectives are necessary to be implemented globally. CONCLUSIONS Although already established diagnosis methods for CT may be sufficient in some regions, there is still a persistent demand to develop tests with higher throughput, cost, and time reduction in developing countries, where prevalence is high. New approaches in CT diagnosis, such as recombinant proteins, capture ELISA, immunochromatography, and POC tests methods, can increase performance in terms of specificity and sensitivity simplifying diagnostic tests' requirements.
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Affiliation(s)
| | | | - Fernando Gómez-Chávez
- Laboratorio de Enfermedades Osteoarticulares e Inmunológicas, Sección de Estudios de Posgrado e Investigación, ENMyH-Instituto Politécnico Nacional, Mexico City, Mexico.
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4
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Surti PV, Kim MW, Phan LMT, Kailasa SK, Mungray AK, Park JP, Park TJ. Progress on dot-blot assay as a promising analytical tool: Detection from molecules to cells. Trends Analyt Chem 2022. [DOI: 10.1016/j.trac.2022.116736] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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A novel enhanced dot blot immunoassay using colorimetric biosensor for detection of Toxoplasma gondii infection. Comp Immunol Microbiol Infect Dis 2021; 79:101708. [PMID: 34481108 DOI: 10.1016/j.cimid.2021.101708] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Revised: 08/25/2021] [Accepted: 08/30/2021] [Indexed: 12/22/2022]
Abstract
This study reports development of a novel point of care assay, namely an enhanced immuno-dot blot assay, for discrimination of anti-Toxoplasma IgG and anti-Toxoplasma IgM antibodies. This method has been designed based on formation of a sandwich complex between a gold nanoprobe (chitosan gold nanoparticle-anti-human IgG or anti-IgM) and anti- Toxoplasma lysate antigen (TLA) which holds anti-TLA antibodies, either IgG or IgM. Briefly, anti-human IgG or anti-IgM antibody was conjugated to chitosan gold nanoparticles via glutaraldehyde chemistry. Then, lysate antigen was immobilized on the surface of nitrocellulose membrane, which followed by addition of the sera sample and gold nanoprobes. The positive signals were readily detectable via observation with naked eye. This positive color change was further intensified via gold enhancement chemistry. The intensity of biosensor signal was proportional to the concentration of active antibodies on the surface of nanoparticles, titer of T. gondii antibodies in the sera samples and concentration of Toxoplasma lysate antigen coated on the nitrocellulose membrane. A minimum concentration to use the antibodies for conjugation, to detect titer of Toxoplasma IgG and IgM antibodies, and the concentration of TLA coated in nitrocellulose membrane were 0.5 mg/mL, 2 IU/mL, 10 IU/mL, and 20 μg/mL, respectively. This enhanced immuno-dot blot assay offers a simple diagnostic technique without expensive equipment requirement for distinguishing of anti- T. gondii IgM and IgG antibodies in field conditions, pregnant women, and immunocompromised patients.
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Karakavuk M, Can H, Gül A, Döşkaya AD, Alak SE, Ün C, Gürüz AY, Döşkaya M. GRA8 DNA vaccine formulations protect against chronic toxoplasmosis. Microb Pathog 2021; 158:105016. [PMID: 34098019 DOI: 10.1016/j.micpath.2021.105016] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 04/28/2021] [Accepted: 05/24/2021] [Indexed: 11/26/2022]
Abstract
Toxoplasma gondii has a very wide host range and infects all warm-blooded animals including humans. The disease causes great economic losses both in animals and humans. Vaccination is the most effective approach to fight against toxoplasmosis however an effective vaccine has not been developed yet. In the present study, GRA8 protein of T. gondii that showed high immunogenicity in our previous microarray screening study was used to develop a DNA vaccine using pcDNA 3.3 vector for the first time. In order to increase the potency of the DNA vaccine, 10 times lower amount of GRA8 DNA vaccine was combined with molecular adjuvant CpG and formulated into a commercial liposome (pcDNA3.3-GRA8+CpG+Escort). Mice were vaccinated intramuscularly two times at three-week intervals and challenged orally with the T. gondii PRU strain tissue cysts. The humoral immune response was determined by Western Blot and ELISA. The cellular immune response was analyzed by flow cytometry, cytokine ELISA and MTT assay. Among the vaccine groups, pcDNA3.3-GRA8 and pcDNA3.3-GRA8+CpG+Escort induced strong IgG response compared to controls (P < 0.001). The IgG1 and IgG2a responses showed a balanced Th1-Th2 polarization. The ratio of CD4+ and CD8+ T lymphocytes secreting IFN-γ increased, and significantly higher extracellular IFN-γ secretion was achieved compared to the controls (P < 0.01). The amount of tissue cysts in the group of mice vaccinated with pcDNA3.3-GRA8 decreased significantly compared to control groups (P < 0.0001). In the group vaccinated with pcDNA3.3-GRA8+CpG+Escort, the amount of tissue cysts also decreased significantly compared to PBS (P = 0.0086) and Empty plasmid+CpG+Escort (P = 0.0007) groups. This study showed for the first time that pcDNA 3.3. vector encoding GRA8 with or without CpG and Liposome can induce strong cellular and humoral immune responses and confer strong protection against mouse model of chronic toxoplasmosis.
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Affiliation(s)
- Muhammet Karakavuk
- Ege University Faculty of Medicine, Department of Parasitology, Bornova, İzmir, Turkey; Ege University, Ege University Ödemiş Vocational School, İzmir, Turkey; Ege University, Vaccine Development, Application and Research Center, Bornova, İzmir, Turkey
| | - Hüseyin Can
- Ege University, Vaccine Development, Application and Research Center, Bornova, İzmir, Turkey; Ege University, Faculty of Science, Department of Biology, Molecular Biology Section, Bornova, İzmir, Turkey
| | - Aytül Gül
- Ege University, Vaccine Development, Application and Research Center, Bornova, İzmir, Turkey; Ege University, Faculty of Engineering, Department of Bioengineering, Bornova, İzmir, Turkey
| | - Aysu Değirmenci Döşkaya
- Ege University Faculty of Medicine, Department of Parasitology, Bornova, İzmir, Turkey; Ege University, Vaccine Development, Application and Research Center, Bornova, İzmir, Turkey
| | - Sedef Erkunt Alak
- Ege University, Faculty of Science, Department of Biology, Molecular Biology Section, Bornova, İzmir, Turkey
| | - Cemal Ün
- Ege University, Faculty of Science, Department of Biology, Molecular Biology Section, Bornova, İzmir, Turkey
| | - Adnan Yüksel Gürüz
- Ege University Faculty of Medicine, Department of Parasitology, Bornova, İzmir, Turkey; Ege University, Vaccine Development, Application and Research Center, Bornova, İzmir, Turkey
| | - Mert Döşkaya
- Ege University Faculty of Medicine, Department of Parasitology, Bornova, İzmir, Turkey; Ege University, Vaccine Development, Application and Research Center, Bornova, İzmir, Turkey.
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Santana SS, Paiva VF, Carvalho FR, Barros HLS, Silva TL, Barros PSC, Pajuaba ACAM, Barros GB, Dietze R, Mineo TWP, Mineo JR. A peptide originated from Toxoplasma gondii microneme 8 displaying serological evidence to differentiate recent from chronic human infection. Parasitol Int 2021; 84:102394. [PMID: 34044107 DOI: 10.1016/j.parint.2021.102394] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2021] [Revised: 05/16/2021] [Accepted: 05/19/2021] [Indexed: 10/21/2022]
Abstract
Toxoplasmosis is able to cause death and/or sequelae in foetuses from pregnant women and immunocompromised individuals. The early diagnosis, able to differentiate acute from chronic phases, is essential to define the treatment against this disease and minimize the risk of complications. Here we describe a peptide derived from microneme 8 (pMIC8) protein of Toxoplasma gondii, able to distinguish the phase of infection. By using human and mice serum samples with different infection times, we assessed the ability of pMIC8 to interact with antibodies present in early of infection, and compared the results obtained with soluble antigen of T. gondii (STAg). The results showed that pMIC8 was recognized more precisely with antibodies present in serum samples from individuals with time of infection below 3 months, followed by those between 4 and 6 months of infection. Based on these results, it is possible to conclude that the association of immunoassays using STAg and pMIC8 as antigen preparations can be used to distinguish acute from chronic infections.
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Affiliation(s)
- Silas Silva Santana
- Laboratory of Immunoparasitology, Institute of Biomedical Sciences, Federal University of Uberlândia, 38400-902 Uberlândia, Minas Gerais, Brazil; Laboratory of Biology, Federal University of Vales do Jequitinhonha e Mucuri, Campus Janaúba, Janaúba, Minas Gerais, Brazil
| | - Vinícius Fernandes Paiva
- Laboratory of Immunoparasitology, Institute of Biomedical Sciences, Federal University of Uberlândia, 38400-902 Uberlândia, Minas Gerais, Brazil
| | - Fernando Reis Carvalho
- Laboratory of Immunoparasitology, Institute of Biomedical Sciences, Federal University of Uberlândia, 38400-902 Uberlândia, Minas Gerais, Brazil; Federal Institute of Education, Science and Technology of Goiás, Campus Itumbiara, Itumbiara, Goiás, 75524-010, Brazil
| | - Heber Leão Silva Barros
- Laboratory of Immunoparasitology, Institute of Biomedical Sciences, Federal University of Uberlândia, 38400-902 Uberlândia, Minas Gerais, Brazil
| | - Tamires Lopes Silva
- Laboratory of Immunoparasitology, Institute of Biomedical Sciences, Federal University of Uberlândia, 38400-902 Uberlândia, Minas Gerais, Brazil
| | - Patrício Silva Cardoso Barros
- Laboratory of Immunoparasitology, Institute of Biomedical Sciences, Federal University of Uberlândia, 38400-902 Uberlândia, Minas Gerais, Brazil
| | - Ana Cláudia Arantes Marquez Pajuaba
- Laboratory of Immunoparasitology, Institute of Biomedical Sciences, Federal University of Uberlândia, 38400-902 Uberlândia, Minas Gerais, Brazil
| | - Geisa Baptista Barros
- Infectious Disease Center, Federal University of Espirito Santo, 29040-091 Vitória, Espírito Santo, Brazil
| | - Reynaldo Dietze
- Infectious Disease Center, Federal University of Espirito Santo, 29040-091 Vitória, Espírito Santo, Brazil
| | - Tiago Wilson Patriarca Mineo
- Laboratory of Immunoparasitology, Institute of Biomedical Sciences, Federal University of Uberlândia, 38400-902 Uberlândia, Minas Gerais, Brazil
| | - José Roberto Mineo
- Laboratory of Immunoparasitology, Institute of Biomedical Sciences, Federal University of Uberlândia, 38400-902 Uberlândia, Minas Gerais, Brazil.
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Hu X, Zhou Z, Li F, Xiao Y, Wang Z, Xu J, Dong F, Zheng H, Yu R. The study of antiviral drugs targeting SARS-CoV-2 nucleocapsid and spike proteins through large-scale compound repurposing. Heliyon 2021; 7:e06387. [PMID: 33688584 PMCID: PMC7919521 DOI: 10.1016/j.heliyon.2021.e06387] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Revised: 02/09/2021] [Accepted: 02/24/2021] [Indexed: 12/17/2022] Open
Abstract
Contributing to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) clinical treatment, a drug library encompassing approximately 3,142 clinical-stage or FDA-approved small molecules is profiled to identify the candidate therapeutic inhibitors targeting nucleocapsid protein (N) and spike protein (S) of SARS-CoV-2. 16 screened candidates with higher binding affinity are evaluated via virtual screening. Comparing to those under trial/temporarily used antivirus drugs (i.e., umifenovir, lopinavir), ceftriaxone, cefotaxime, and cefuroxime show higher binding affinities to the N-terminal domain of N protein (N-NTD), C-terminal domain of N protein (N-CTD), and receptor-binding domain of S protein (S-RBD). Cefotaxime and cefuroxime have high binding affinities towards S-RBD with angiotensin-converting enzyme 2 (ACE2) complex via influence the critical interface sites at the interface of S-RBD (Arg403, Tyr453, Trp495, Gly496, Phe497, Asn501and Tyr505) and ACE2 (Asn33, His34, Glu37, Asp38, Lys353, Ala386, Ala387, Gln388, Pro389, Phe390 and Arg393) complex.
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Affiliation(s)
- Xuqiao Hu
- Department of Ultrasound, First Affiliated Hospital of Southern University of Science and Technology, Second Clinical Medical College of Jinan University (Shenzhen People's Hospital), Shenzhen, 518020, China.,Integrated Chinese and Western Medicine Postdoctoral Research Station, Jinan University, Guangzhou, 510632, China
| | - Zhenru Zhou
- Department of Ultrasound, First Affiliated Hospital of Southern University of Science and Technology, Second Clinical Medical College of Jinan University (Shenzhen People's Hospital), Shenzhen, 518020, China
| | - Fei Li
- Paul C. Lauterbur Research Center for Biomedical Imaging, Institute of Biomedical and Health Engineering, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, 1068 Xueyuan Avenue, SZ University Town, Shenzhen, 518055, China
| | - Yang Xiao
- Paul C. Lauterbur Research Center for Biomedical Imaging, Institute of Biomedical and Health Engineering, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, 1068 Xueyuan Avenue, SZ University Town, Shenzhen, 518055, China
| | - Zhaoyang Wang
- Department of Ultrasound, First Affiliated Hospital of Southern University of Science and Technology, Second Clinical Medical College of Jinan University (Shenzhen People's Hospital), Shenzhen, 518020, China
| | - Jinfeng Xu
- Department of Ultrasound, First Affiliated Hospital of Southern University of Science and Technology, Second Clinical Medical College of Jinan University (Shenzhen People's Hospital), Shenzhen, 518020, China
| | - Fajin Dong
- Department of Ultrasound, First Affiliated Hospital of Southern University of Science and Technology, Second Clinical Medical College of Jinan University (Shenzhen People's Hospital), Shenzhen, 518020, China
| | - Hairong Zheng
- Paul C. Lauterbur Research Center for Biomedical Imaging, Institute of Biomedical and Health Engineering, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, 1068 Xueyuan Avenue, SZ University Town, Shenzhen, 518055, China
| | - Rongmin Yu
- Integrated Chinese and Western Medicine Postdoctoral Research Station, Jinan University, Guangzhou, 510632, China.,Department of Pharmacology, College of Pharmacy, Jinan University, 601 Huangpu Avenue West, Guangzhou, 510632, China.,Biotechnological Institute of Chinese Materia Medica, Jinan University, 601 Huangpu Avenue West, Guangzhou, 510632, China
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9
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Teimouri A, Modarressi MH, Shojaee S, Mohebali M, Rezaian M, Keshavarz H. Development, optimization, and validation of an in-house Dot-ELISA rapid test based on SAG1 and GRA7 proteins for serological detection of Toxoplasma gondii infections. Infect Drug Resist 2019; 12:2657-2669. [PMID: 31695442 PMCID: PMC6717716 DOI: 10.2147/idr.s219281] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Accepted: 07/27/2019] [Indexed: 01/08/2023] Open
Abstract
Background The aim of the present study was to develop a simple, portable, and rapid assay for serodiagnosis of toxoplasmosis based on recombinant Toxoplasma gondii (T. gondii) SAG1 (rSAG1) and GRA7 (rGRA7) proteins. Methods The rSAG1 and rGRA7 proteins were expressed in Escherichia coli (E. coli) and purified in a single step by immobilized metal ion affinity chromatography. The immunoreactivity of the recombinant antigens was tested in an in-house IgG and IgM Dot enzyme-linked immunosorbent assay (Dot-ELISA) for potential use in serodiagnosis of T. gondii infection. Results Results from the comparison of in-house rSAG1-Dot-ELISA with ELISA for the detection of anti-Toxoplasma IgG and IgM include sensitivity of 83.7% and 81.2%, specificity of 90.2% and 89.3%, positive predictive values of 85.9% and 68.4%, and negative predictive values of 88.6% and 94.3%, respectively. Sensitivity of 66.2%, specificity of 81.2%, positive predictive values of 71.6%, and negative predictive values of 77.1% were concluded from in-house IgG rGRA7-Dot-ELISA. The sensitivity and specificity of IgM rGRA7-Dot-ELISA included 87.5% and 83.9%, respectively. Sensitivity and specificity of in-house Dot-ELISA for a combination of rSAG1 and rGRA7 included 87.5% and 91.1% for IgG and IgM, respectively. Sensitivity and specificity of a combination of rSAG1 and rGRA7 for the detection of IgM in suspected sera to acute toxoplasmosis were higher than those for the detection of IgG in sera with chronic infections (90.6% and 92% instead of 86.2% and 91.6%, respectively). Conclusion The highlighted parameters of combined recombinant proteins were more significant than those of single recombinant proteins in in-house Dot-ELISA. These data suggest that the in-house Dot-ELISA based on rSAG1 and rGRA7 combination is a promising diagnostic tool with a similar sensitivity to the native antigens of T. gondii, which can be used for the serodiagnosis of toxoplasmosis in fields as well as less equipped laboratories.
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Affiliation(s)
- Aref Teimouri
- Department of Medical Parasitology and Mycology, Tehran University of Medical Sciences, Tehran, Iran.,Students Scientific Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | | | - Saeedeh Shojaee
- Department of Medical Parasitology and Mycology, Tehran University of Medical Sciences, Tehran, Iran
| | - Mehdi Mohebali
- Department of Medical Parasitology and Mycology, Tehran University of Medical Sciences, Tehran, Iran.,Center for Research of Endemic Parasites of Iran, Tehran University of Medical Sciences, Tehran, Iran
| | - Mostafa Rezaian
- Department of Medical Parasitology and Mycology, Tehran University of Medical Sciences, Tehran, Iran
| | - Hossein Keshavarz
- Department of Medical Parasitology and Mycology, Tehran University of Medical Sciences, Tehran, Iran.,Center for Research of Endemic Parasites of Iran, Tehran University of Medical Sciences, Tehran, Iran
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