{ "abstract": "Alveolar echinococcosis (AE) is a severe zoonotic parasitic disease caused by the larval stage of Echinococcus multilocularis, for which early and accurate diagnosis remains challenging. In this study, we targeted E. multilocularis thioredoxin peroxidase (EmTPx), a highly abundant excretory/secretory protein conserved across the genus Echinococcus, for diagnostic development. Monoclonal antibodies (mAbs) against EmTPx were generated, and two linear B‑cell epitopes, 174HPGSK178 and 189SFMSS193, were identified. Both epitopes are strictly conserved within Echinococcus but markedly divergent from mammalian host sequences. Structural modeling revealed that the epitopes are surface‑exposed, with 174HPGSK178 located in a flexible loop and 189SFMSS193 adjacent to an α‑helix, conformations favorable for antibody recognition. Two ELISA methods were established using the epitope‑specific mAbs. The blocking ELISA showed moderate diagnostic performance. More importantly, the sandwich ELISA enabled direct detection of EmTPx antigen in fecal samples of intermediate hosts, revealing a detection rate of 85% in mouse feces at an early infection stage. With a linear range of 0–250 ng/mL, a cutoff of 0.1724, and intra‑ and inter‑assay precision below 10%, this sandwich ELISA demonstrated robust analytical performance. In conclusion, this proof-of-concept study identifies two evolutionarily conserved and structurally exposed EmTPx epitopes and demonstrates their potential utility for the development of monoclonal antibody-based approaches for non-invasive detection of echinococcosis. Author summary: Alveolar echinococcosis (AE) is a life-threatening parasitic disease caused by the larval stage of Echinococcus multilocularis. Early diagnosis remains challenging, as current blood-based tests detect host antibodies but often fail in immunocompromised individuals and cannot reliably distinguish active from past infection. In this study, we developed a non-invasive diagnostic approach that directly detects a parasite excretory/secretory protein called thioredoxin peroxidase (EmTPx) in fecal samples. We generated monoclonal antibodies targeting two specific regions of EmTPx that are highly conserved among Echinococcus species yet markedly different from mammalian TPx homologs, ensuring specific recognition of the parasite. Using these antibodies, we constructed a sandwich ELISA and successfully detected EmTPx in the feces of experimentally infected mice at an early stage of infection. This finding supports a mechanistic model in which parasite proteins released from hepatic lesions reach the intestinal lumen through hepatobiliary transport, thereby enabling non-invasive fecal detection. Beyond providing a theoretical foundation for discovering additional coproantigen targets, this approach offers a promising tool for early diagnosis and large-scale screening of AE, particularly in resource-limited endemic settings where current diagnostic methods are unavailable or insufficient.", "abstract_shown": true, "affiliations": [ "Key Laboratory of Animal Disease Diagnostics and Immunology, Ministry of Agriculture, MOE International Joint Collaborative Research Laboratory for Animal Health & Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China", "Academy of Animal Science and Veterinary, Qinghai Provincial Key Laboratory of Pathogen Diagnosis for Animal Diseases and Green Technical Research for Prevention and Control, Qinghai University, Xining, China", "The Haixi Prefecture Center for Animal Disease Control and Prevention, Delingha, China", "The Wulan County Center for Disease Control and Prevention, Wulan, China" ], "article_type": "Research Article", "arxiv": null, "author_total": 19, "authors": [ { "affs": [ 0 ], "name": "Lijuan Zheng" }, { "affs": [ 1 ], "name": "Wenjing Zhi" }, { "affs": [ 2 ], "name": "Mengjie Chu" }, { "affs": [ 3 ], "name": "Xinyi Zhou" }, { "name": "Yong Fu" }, { "name": "Chen Xin" }, { "name": "Baoping Li" }, { "name": "Lingzhi Pengmao" }, { "name": "Zhendong Xin" }, { "name": "Yihui Wu" }, { "name": "Xuejun Ji" }, { "name": "Anni Zhang" }, { "name": "Changjie Qian" }, { "name": "Zhen Wang" }, { "name": "Chenye Jin" }, { "name": "Yun Han" }, { "name": "Zhijun Zhang" }, { "name": "Fuyun Chen" }, { "name": "Gongguan Liu" } ], "bibtex": "https://research.draconitic.com/paper/dzkgta6c033dv.bib", "cited_by": 0, "doi": "10.1371/journal.pntd.0014755", "fulltext_url": "https://journals.plos.org/plosntds/article?id=10.1371/journal.pntd.0014755", "id": "dzkgta6c033dv", "issns": [ "1935-2735" ], "landing_url": "https://journals.plos.org/plosntds/article?id=10.1371/journal.pntd.0014755", "language": null, "licence": "CC-BY-4.0", "licence_label": "CC BY 4.0", "licence_source": "journal", "licence_url": "https://creativecommons.org/licenses/by/4.0/", "metadata_licence": null, "native_subjects": [ [ "openalex", "2734|Parasitic infections in humans and animals" ], [ "plos", "/Biology and life sciences/Biochemistry/Proteins/Immune system proteins/Antibodies" ], [ "plos", "/Biology and life sciences/Biochemistry/Proteins/Immune system proteins/Antibodies/Monoclonal antibodies" ], [ "plos", "/Biology and life sciences/Biochemistry/Proteins/Recombinant proteins" ], [ "plos", "/Biology and life sciences/Immunology/Immune system proteins/Antibodies" ], [ "plos", "/Biology and life sciences/Immunology/Immune system proteins/Antibodies/Monoclonal antibodies" ], [ "plos", "/Biology and life sciences/Physiology/Immune physiology/Antibodies" ], [ "plos", "/Biology and life sciences/Physiology/Immune physiology/Antibodies/Monoclonal antibodies" ], [ "plos", "/Medicine and health sciences/Immunology/Immune system proteins/Antibodies" ], [ "plos", "/Medicine and health sciences/Immunology/Immune system proteins/Antibodies/Monoclonal antibodies" ], [ "plos", "/Medicine and health sciences/Medical conditions/Parasitic diseases" ], [ "plos", "/Medicine and health sciences/Medical conditions/Parasitic diseases/Helminth infections/Echinococcosis" ], [ "plos", "/Medicine and health sciences/Medical conditions/Parasitic diseases/Parasitic intestinal diseases" ], [ "plos", "/Medicine and health sciences/Medical conditions/Tropical diseases/Neglected tropical diseases/Echinococcosis" ], [ "plos", "/Research and analysis methods/Histochemistry and cytochemistry techniques/Immunohistochemistry techniques" ], [ "plos", "/Research and analysis methods/Immunologic techniques/Immunoassays/Enzyme-linked immunoassays" ], [ "plos", "/Research and analysis methods/Immunologic techniques/Immunohistochemistry techniques" ] ], "openalex": "W7214028320", "pdf_url": "https://journals.plos.org/plosntds/article/file?id=10.1371/journal.pntd.0014755&type=printable", "pmcid": null, "pmid": null, "published": "2026-09-22", "publisher": "Public Library of Science", "ris": "https://research.draconitic.com/paper/dzkgta6c033dv.ris", "sources": [ { "first_seen": "2026-10-30T12:17:43Z", "native_id": "10.1371/journal.pntd.0014755", "source": "plos", "url": "https://journals.plos.org/plosntds/article?id=10.1371/journal.pntd.0014755" } ], "subjects": [ { "field": "biology", "origin": "plos:immunology", "subfield": "immunology" }, { "field": "medicine", "origin": "plos:physiology", "subfield": "physiology" } ], "title": "Conserved surface-exposed linear epitopes of Echinococcus multilocularis thioredoxin peroxidase enable non-invasive diagnosis of alveolar echinococcosis in intermediate host", "title_text": "Conserved surface-exposed linear epitopes of Echinococcus multilocularis thioredoxin peroxidase enable non-invasive diagnosis of alveolar echinococcosis in intermediate host", "type": "peer-reviewed", "updated_at": "2026-10-30T12:17:43Z", "url": "https://research.draconitic.com/paper/dzkgta6c033dv", "venue": "PLOS Neglected Tropical Diseases", "versions": [] }