{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,31]],"date-time":"2026-08-31T07:51:13Z","timestamp":1788162673041,"version":"build-2803163510"},"reference-count":51,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2025,6,12]],"date-time":"2025-06-12T00:00:00Z","timestamp":1749686400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100004281","name":"National Science Centre, Poland","doi-asserted-by":"publisher","award":["UMO-2018\/31\/D\/NZ6\/02839"],"award-info":[{"award-number":["UMO-2018\/31\/D\/NZ6\/02839"]}],"id":[{"id":"10.13039\/501100004281","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJMS"],"abstract":"<jats:p>Toxoplasmosis is one of the most common and neglected parasitic diseases caused by the intracellular parasite Toxoplasma gondii. The parasitic invasion in humans is associated with certain problems, such as the lack of effective immunoprophylaxis or a complex diagnostic algorithm, which require continuous improvement. Both problems can be overcome by the recent development of T. gondii proteomics, which has allowed the design of different recombinant antigens. In this study we evaluated the potential usefulness of nineteen recombinant chimeric T. gondii proteins for serodiagnosis. A chimeric antigen composed of the surface antigens SAG1-SAG2 was developed and used as the basis for the generation of 18 subsequent trivalent chimeric antigens containing different immunodominant fragments of the parasite proteins. The recombinant antigens were used in an indirect enzyme-linked immunosorbent assay (ELISA) test to evaluate their ability to detect specific IgG antibodies in human sera. A total of 338 human sera were analyzed to assess the sensitivity and specificity of the tests. Sixteen of the antigens tested demonstrated 100% sensitivity and specificity in the ELISA for the detection of specific IgG antibodies. These results provide an optimistic outlook for the potential replacement of the currently used native antigen mix with recombinant antigens in human T. gondii serodiagnostics.<\/jats:p>","DOI":"10.3390\/ijms26125621","type":"journal-article","created":{"date-parts":[[2025,6,12]],"date-time":"2025-06-12T03:59:17Z","timestamp":1749700757000},"page":"5621","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":3,"title":["The Trivalent Recombinant Chimeric Proteins Containing Immunodominant Fragments of Toxoplasma gondii SAG1 and SAG2 Antigens in Their Core\u2014A Good Diagnostic Tool for Detecting IgG Antibodies in Human Serum Samples"],"prefix":"10.3390","volume":"26","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-2176-3966","authenticated-orcid":false,"given":"Bart\u0142omiej Tomasz","family":"Ferra","sequence":"first","affiliation":[{"name":"Department of Tropical Parasitology, Institute of Maritime and Tropical Medicine in Gdynia, Medical University of Gda\u0144sk, Powstania Styczniowego 9B, 81-519 Gdynia, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3964-671X","authenticated-orcid":false,"given":"Maciej","family":"Chyb","sequence":"additional","affiliation":[{"name":"Department of Molecular Microbiology, Faculty of Biology and Environmental Protection, University of Lodz, Banacha 12\/16, 90-237 \u0141\u00f3d\u017a, Poland"},{"name":"Bio-Med-Chem Doctoral School of the University of Lodz and Lodz Institutes of the Polish Academy of Sciences, Faculty of Biology and Environmental Protection, University of Lodz, Banacha 12\/16, 90-237 \u0141\u00f3d\u017a, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Marta","family":"Skwarecka","sequence":"additional","affiliation":[{"name":"Department of Molecular Genetics of Bacteria, Faculty of Biology, University of Gdansk, Wita Stwosza 59, 80-308 Gda\u0144sk, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0559-1706","authenticated-orcid":false,"given":"Justyna","family":"Gatkowska","sequence":"additional","affiliation":[{"name":"Department of Molecular Microbiology, Faculty of Biology and Environmental Protection, University of Lodz, Banacha 12\/16, 90-237 \u0141\u00f3d\u017a, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,6,12]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1217","DOI":"10.1016\/S0020-7519(00)00124-7","article-title":"Toxoplasma gondii: From Animals to Humans","volume":"30","author":"Tenter","year":"2000","journal-title":"Int. J. Parasitol."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"371","DOI":"10.1016\/j.rvsc.2020.10.019","article-title":"Foodborne Transmission of Toxoplasma gondii Infection in the Last Decade. An Overview","volume":"135","author":"Almeria","year":"2021","journal-title":"Res. Vet. Sci."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"588","DOI":"10.1186\/s13071-020-04445-z","article-title":"The Life-Cycle of Toxoplasma gondii Reviewed Using Animations","volume":"13","author":"Attias","year":"2020","journal-title":"Parasit. Vectors"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"291","DOI":"10.1016\/j.ijppaw.2015.05.005","article-title":"Sea Otter Health: Challenging a Pet Hypothesis","volume":"4","author":"Lafferty","year":"2015","journal-title":"Int. J. Parasitol. Parasites Wildl."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"133","DOI":"10.1016\/j.vetpar.2018.05.011","article-title":"An Update on Toxoplasma gondii Infections in Northern Sea Otters (Enhydra Lutris Kenyoni) from Washington State, USA","volume":"258","author":"Verma","year":"2018","journal-title":"Vet. Parasitol."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"845","DOI":"10.1093\/cid\/cis508","article-title":"Foodborne Toxoplasmosis","volume":"55","author":"Jones","year":"2012","journal-title":"Clin. Infect. Dis."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"107","DOI":"10.1016\/j.ijpara.2012.09.012","article-title":"Toxoplasma gondii Prevalence in Farm Animals in the United States","volume":"43","author":"Hill","year":"2013","journal-title":"Int. J. Parasitol."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1257","DOI":"10.1016\/j.ijpara.2008.03.007","article-title":"Toxoplasma gondii Infection in Humans and Animals in the United States","volume":"38","author":"Dubey","year":"2008","journal-title":"Int. J. Parasitol."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"95","DOI":"10.1016\/j.ijpara.2020.11.001","article-title":"Control of Human Toxoplasmosis","volume":"51","author":"Smith","year":"2021","journal-title":"Int. J. Parasitol."},{"key":"ref_10","doi-asserted-by":"crossref","unstructured":"Miyagaki, M., Zong, Y., Yang, M., Zhang, J., Zou, Y., Ohno-Matsui, K., and Kamoi, K. (2024). Ocular Toxoplasmosis: Advances in Toxoplasma gondii Biology, Clinical Manifestations, Diagnostics, and Therapy. Pathogens, 13.","DOI":"10.3390\/pathogens13100898"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"959","DOI":"10.1016\/j.pt.2020.08.005","article-title":"Toxoplasma gondii: An Underestimated Threat?","volume":"36","author":"Milne","year":"2020","journal-title":"Trends Parasitol."},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Gatkowska, J., Dzitko, K., Ferra, B.T., Holec-G\u0105sior, L., Kawka, M., and Dziadek, B. (2019). The Impact of the Antigenic Composition of Chimeric Proteins on Their Immunoprotective Activity against Chronic Toxoplasmosis in Mice. Vaccines, 7.","DOI":"10.3390\/vaccines7040154"},{"key":"ref_13","first-page":"81","article-title":"Serodiagnosis of Toxoplasmosis. The Impact of Measurement of IgG Avidity","volume":"40","author":"Lappalainen","year":"2004","journal-title":"Ann. Ist. Super. Sanita"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"139","DOI":"10.1016\/j.actatropica.2017.04.008","article-title":"Serodiagnosis of Toxoplasmosis: The Effect of Measurement of IgG Avidity in Pregnant Women in Rabat in Morocco","volume":"172","author":"Laboudi","year":"2017","journal-title":"Acta Trop."},{"key":"ref_15","first-page":"977","article-title":"Seroreactivity to and Avidity for Recombinant Antigens in Toxoplasmosis","volume":"12","author":"Pfrepper","year":"2005","journal-title":"Clin. Diagn. Lab. Immunol."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"312","DOI":"10.1136\/jcp.51.4.312","article-title":"Do IgA, IgE, and IgG Avidity Tests Have Any Value in the Diagnosis of Toxoplasma Infection in Pregnancy?","volume":"51","author":"Ashburn","year":"1998","journal-title":"J. Clin. Pathol."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"605","DOI":"10.1136\/jcp.45.7.605","article-title":"IgA Antibody Response during Acquired and Congenital Toxoplasmosis","volume":"45","author":"Bessieres","year":"1992","journal-title":"J. Clin. Pathol."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"292","DOI":"10.1186\/s13071-015-0902-6","article-title":"Diagnosis of Toxoplasmosis and Typing of Toxoplasma gondii","volume":"8","author":"Liu","year":"2015","journal-title":"Parasit. Vectors"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"1343","DOI":"10.1128\/CVI.00117-13","article-title":"Toxoplasma gondii Recombinant Antigens as Tools for Serodiagnosis of Human Toxoplasmosis: Current Status of Studies","volume":"20","year":"2013","journal-title":"Clin. Vaccine Immunol."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"273","DOI":"10.1080\/14712598.2018.1413086","article-title":"Moving towards Improved Vaccines for Toxoplasma gondii","volume":"18","author":"Li","year":"2018","journal-title":"Expert. Opin. Biol. Ther."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"308","DOI":"10.1016\/0169-4758(96)10030-2","article-title":"Rhoptry Organelles of the Apicomplexa: Their Role in Host Cell Invasion and Intracellular Survival","volume":"12","year":"1996","journal-title":"Parasitol. Today"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"225","DOI":"10.1046\/j.1462-5822.1999.00023.x","article-title":"Secretion of Micronemal Proteins Is Associated with Toxoplasma Invasion of Host Cells","volume":"1","author":"Carruthers","year":"1999","journal-title":"Cell. Microbiol."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"89","DOI":"10.1006\/expr.2000.4556","article-title":"Toxoplasma gondii: Identification of a Developmentally Regulated Family of Genes Related to SAG2","volume":"96","author":"Lekutis","year":"2000","journal-title":"Exp. Parasitol."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"1285","DOI":"10.1016\/S0020-7519(01)00261-2","article-title":"Surface Antigens of Toxoplasma gondii: Variations on a Theme","volume":"31","author":"Lekutis","year":"2001","journal-title":"Int. J. Parasitol."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"557","DOI":"10.1083\/jcb.200112144","article-title":"Secretory Traffic in the Eukaryotic Parasite Toxoplasma gondii","volume":"157","author":"Joiner","year":"2002","journal-title":"J. Cell Biol."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"829","DOI":"10.1016\/j.ijpara.2005.03.011","article-title":"Dense Granules: Are They Key Organelles to Help Understand the Parasitophorous Vacuole of All Apicomplexa Parasites?","volume":"35","author":"Mercier","year":"2005","journal-title":"Int. J. Parasitol."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"2397","DOI":"10.1091\/mbc.e02-01-0021","article-title":"Biogenesis of Nanotubular Network in Toxoplasma Parasitophorous Vacuole Induced by Parasite Proteins","volume":"13","author":"Mercier","year":"2002","journal-title":"Mol. Biol. Cell"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"2237","DOI":"10.1128\/IAI.66.5.2237-2244.1998","article-title":"The Surface of Toxoplasma Tachyzoites Is Dominated by a Family of Glycosylphosphatidylinositol-Anchored Antigens Related to SAG1","volume":"66","author":"Manger","year":"1998","journal-title":"Infect. Immun."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"285","DOI":"10.1016\/j.ijpara.2003.12.004","article-title":"The SRS Superfamily of Toxoplasma Surface Proteins","volume":"34","author":"Jung","year":"2004","journal-title":"Int. J. Parasitol."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"5569","DOI":"10.1016\/S0021-9258(18)83584-0","article-title":"The Major Surface Antigen, P30, of Toxoplasma gondii Is Anchored by a Glycolipid","volume":"264","author":"Nagel","year":"1989","journal-title":"J. Biol. Chem."},{"key":"ref_31","first-page":"114","article-title":"Sequential Protein Secretion Front Three Distinct Organelles of Toxoplasma gondii Accompanies Invasion of Human Fibroblasts","volume":"73","author":"Carruthers","year":"1997","journal-title":"Eur. J. Cell Biol."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"582","DOI":"10.1016\/j.mib.2007.09.013","article-title":"Rhoptries: An Arsenal of Secreted Virulence Factors","volume":"10","author":"Bradley","year":"2007","journal-title":"Curr. Opin. Microbiol."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"89","DOI":"10.1016\/j.exppara.2017.03.001","article-title":"Research Advances in Interactions Related to Toxoplasma gondii Microneme Proteins","volume":"176","author":"Liu","year":"2017","journal-title":"Exp. Parasitol."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"25","DOI":"10.1016\/j.micron.2007.08.007","article-title":"Immunolocalization of an Osteopontin-like Protein in Dense Granules of Toxoplasma gondii Tachyzoites and Its Association with the Parasitophorous Vacuole","volume":"39","author":"Cortez","year":"2008","journal-title":"Micron"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"e13011","DOI":"10.1111\/cmi.13011","article-title":"Calcium Negatively Regulates Secretion from Dense Granules in Toxoplasma gondii","volume":"21","author":"Katris","year":"2019","journal-title":"Cell. Microbiol."},{"key":"ref_36","doi-asserted-by":"crossref","unstructured":"Ferra, B.T., Chyb, M., So\u0142owi\u0144ska, K., Holec-G\u0105sior, L., Skwarecka, M., Baranowicz, K., and Gatkowska, J. (2024). The Development of Toxoplasma gondii Recombinant Trivalent Chimeric Proteins as an Alternative to Toxoplasma Lysate Antigen (TLA) in Enzyme-Linked Immunosorbent Assay (ELISA) for the Detection of Immunoglobulin G (IgG) in Small Ruminants. Int. J. Mol. Sci., 25.","DOI":"10.3390\/ijms25084384"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"1359","DOI":"10.1016\/j.ijpara.2008.06.002","article-title":"Control of the Risk of Human Toxoplasmosis Transmitted by Meat","volume":"38","author":"Kijlstra","year":"2008","journal-title":"Int. J. Parasitol."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"18","DOI":"10.1016\/j.pt.2008.09.008","article-title":"Toxoplasma-Safe Meat: Close to Reality?","volume":"25","author":"Kijlstra","year":"2009","journal-title":"Trends Parasitol."},{"key":"ref_39","first-page":"e06406","article-title":"The European Union One Health 2019 Zoonoses Report","volume":"19","author":"Boelaert","year":"2021","journal-title":"EFSA J."},{"key":"ref_40","doi-asserted-by":"crossref","unstructured":"Mar\u00edn-Garc\u00eda, P.J., Planas, N., and Llobat, L. (2022). Toxoplasma gondii in Foods: Prevalence, Control, and Safety. Foods, 11.","DOI":"10.3390\/foods11162542"},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"e90203","DOI":"10.1371\/journal.pone.0090203","article-title":"Toxoplasmosis\u2014A Global Threat. Correlation of Latent Toxoplasmosis with Specific Disease Burden in a Set of 88 Countries","volume":"9","author":"Flegr","year":"2014","journal-title":"PLoS ONE"},{"key":"ref_42","doi-asserted-by":"crossref","unstructured":"Ferra, B., Holec-G\u0105sior, L., and Gra\u017alewska, W. (2020). Toxoplasma gondii Recombinant Antigens in the Serodiagnosis of Toxoplasmosis in Domestic and Farm Animals. Animals, 10.","DOI":"10.3390\/ani10081245"},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"871","DOI":"10.1007\/s00436-011-2315-6","article-title":"Immunogenic Characterization of the Chimeric Surface Antigen 1 and 2 (SAG1\/2) of Toxoplasma gondii Expressed in the Yeast Pichia Pastoris","volume":"109","author":"Lau","year":"2011","journal-title":"Parasitol. Res."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"2133","DOI":"10.1128\/JCM.00237-06","article-title":"Chimeric Antigens of Toxoplasma gondii: Toward Standardization of Toxoplasmosis Serodiagnosis Using Recombinant Products","volume":"44","author":"Beghetto","year":"2006","journal-title":"J. Clin. Microbiol."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"338","DOI":"10.1128\/CVI.05553-11","article-title":"Evaluation of a Recombinant Multiepitope Peptide for Serodiagnosis of Toxoplasma gondii Infection","volume":"19","author":"Dai","year":"2012","journal-title":"Clin. Vaccine Immunol."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"95","DOI":"10.1016\/j.exppara.2012.10.016","article-title":"Toxoplasma gondii: Enzyme-Linked Immunosorbent Assay Based on a Recombinant Multi-Epitope Peptide for Distinguishing Recent from Past Infection in Human Sera","volume":"133","author":"Dai","year":"2013","journal-title":"Exp. Parasitol."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"34","DOI":"10.1016\/j.diagmicrobio.2015.01.018","article-title":"New Recombinant Chimeric Antigens, P35-MAG1, MIC1-ROP1, and MAG1-ROP1, for the Serodiagnosis of Human Toxoplasmosis","volume":"82","author":"Kur","year":"2015","journal-title":"Diagn. Microbiol. Infect. Dis."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"57","DOI":"10.1128\/CVI.05433-11","article-title":"A New MIC1-MAG1 Recombinant Chimeric Antigen Can Be Used Instead of the Toxoplasma gondii Lysate Antigen in Serodiagnosis of Human Toxoplasmosis","volume":"19","author":"Ferra","year":"2012","journal-title":"Clin. Vaccine Immunol."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"1977","DOI":"10.1128\/CVI.00452-12","article-title":"MIC1-MAG1-SAG1 Chimeric Protein, a Most Effective Antigen for Detection of Human Toxoplasmosis","volume":"19","author":"Ferra","year":"2012","journal-title":"Clin. Vaccine Immunol."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"3291","DOI":"10.1007\/s00436-015-4552-6","article-title":"A New Toxoplasma gondii Chimeric Antigen Containing Fragments of SAG2, GRA1, and ROP1 Proteins\u2014Impact of Immunodominant Sequences Size on Its Diagnostic Usefulness","volume":"114","author":"Ferra","year":"2015","journal-title":"Parasitol. Res."},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"e0217866","DOI":"10.1371\/journal.pone.0217866","article-title":"The First Study on the Usefulness of Recombinant Tetravalent Chimeric Proteins Containing Fragments of SAG2, GRA1, ROP1 and AMA1 Antigens in the Detection of Specific Anti-Toxoplasma gondii Antibodies in Mouse and Human Sera","volume":"14","author":"Ferra","year":"2019","journal-title":"PLoS ONE"}],"container-title":["International Journal of Molecular Sciences"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1422-0067\/26\/12\/5621\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,9]],"date-time":"2025-10-09T17:50:28Z","timestamp":1760032228000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1422-0067\/26\/12\/5621"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,6,12]]},"references-count":51,"journal-issue":{"issue":"12","published-online":{"date-parts":[[2025,6]]}},"alternative-id":["ijms26125621"],"URL":"https:\/\/doi.org\/10.3390\/ijms26125621","relation":{},"ISSN":["1422-0067"],"issn-type":[{"value":"1422-0067","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,6,12]]}}}