Production of recombinant electron transfer flavoprotein beta subunit protein and its application in a lateral flow assay for early diagnosis of leptospirosis
Issued Date
2025-12-01
Resource Type
ISSN
03008584
eISSN
14321831
Scopus ID
2-s2.0-85218463165
Journal Title
Medical Microbiology and Immunology
Volume
214
Issue
1
Rights Holder(s)
SCOPUS
Bibliographic Citation
Medical Microbiology and Immunology Vol.214 No.1 (2025)
Suggested Citation
Kositanont U., Thawornkuno C., Sitthipunya A., Dachavichitlead W., Tribuddharat C., Brameld S., Doungchawee G., Lertanantawong B., Srisawat C. Production of recombinant electron transfer flavoprotein beta subunit protein and its application in a lateral flow assay for early diagnosis of leptospirosis. Medical Microbiology and Immunology Vol.214 No.1 (2025). doi:10.1007/s00430-025-00822-6 Retrieved from: https://repository.li.mahidol.ac.th/handle/123456789/105503
Title
Production of recombinant electron transfer flavoprotein beta subunit protein and its application in a lateral flow assay for early diagnosis of leptospirosis
Corresponding Author(s)
Other Contributor(s)
Abstract
Leptospirosis is a major cause of acute febrile illness, often presenting with non-specific symptoms that can lead to misdiagnosis. Early laboratory diagnosis is essential for confirmation to avoid misdiagnosis and ensure appropriate management. This study aimed to identify and produce a recombinant protein, approximately 25 kDa, with high antigenicity for diagnostic applications. The 25 kDa protein from Leptospira interrogans was identified as electron transfer flavoprotein beta subunits (Etfβ) and exhibited 98% nucleotide and 99% amino acid homology to the reference strain. Lateral flow assays (LFAs) using recombinant Etfβ (rEtfβ) as antigens were developed to detect specific antibodies, namely rEtfβ-IgM and rEtfβ-IgG, and evaluated their performance against the standard microscopic agglutination test (MAT). Testing 33 paired serum samples from confirmed leptospirosis cases and 24 controls revealed sensitivities of 69.7% for IgM and 57.6% for IgG. However, the combined assays yielded enhanced diagnostic accuracy, achieving a sensitivity of 94.0%, specificity of 95.8%, positive predictive value of 96.9%, negative predictive value of 92.0%, and percent agreement of 94.7% (kappa value of 0.89). Also, the combined LFAs demonstrated 66.7% in initial serum samples whose MAT results were negative, enhancing the capacity for early diagnosis. In conclusion, the developed rapid tests demonstrated strong diagnostic capability, particularly in early-phase leptospirosis, distinguishing between initial and recurrent infections. Importantly, rEtfβ-IgG identified a subset of patients lacking detectable IgM. Thus, integrating rEtfβ-IgM and rEtfβ-IgG is recommended to improve sensitivity and accuracy in endemic populations. The rEtfβ is a promising target for future antigen-based diagnostic strategies for leptospirosis. The rEtfβ antigen shows promise as a target for future development of antigen-based diagnostic strategies for leptospirosis.