Evaluation of new leptospiral antigens for the diagnosis of equine leptospirosis: An approach using pan-genomic analysis, reverse vaccinology and antigenic selection.
Authors: Zilch Tiago J, Lee Jen-Jie, Bressan Gustavo C, McDonough Sean P, Mohammed Hussni O, Divers Thomas J, Chang Yung-Fu
Journal: Equine veterinary journal
Summary
# Editorial Summary: Novel Leptospiral Antigens for Equine Diagnosis Equine leptospirosis diagnosis currently relies on the microscopic agglutination test (MAT), a labour-intensive method with significant limitations that hinders rapid clinical decision-making. Researchers applied reverse vaccinology and computational antigenic selection to identify and validate novel leptospiral proteins capable of serving as diagnostic reagents, screening 128 equine sera against newly cloned and expressed candidates using serological analysis. Testing revealed that selected antigens achieved improved sensitivity and specificity compared to conventional approaches, with potential for serovar-specific identification beyond simple exposure detection. For practitioners, these findings suggest that ELISA-based assays incorporating these novel antigens could offer faster, more accessible alternatives to MAT whilst maintaining diagnostic accuracy—particularly valuable for resource-limited settings or high-throughput screening scenarios. However, the study's reliance on MAT as a reference standard and its limitation to seven serovars means further validation across diverse geographic regions and additional Leptospira serovars will be necessary before these antigens become clinically routine.
Read the full abstract on PubMed
Practical Takeaways
- •Current MAT testing for equine leptospirosis has significant limitations; these new antigens may enable development of faster, more reliable ELISA-based diagnostic tests for field use
- •Improved diagnostic sensitivity and specificity could enhance detection of leptospirosis in horses and potentially identify the infecting serovar, guiding more targeted treatment decisions
- •Future validation with broader geographic serum samples and additional serovars will be needed before these antigens can be implemented in routine clinical practice
Key Findings
- •New leptospiral antigens identified through reverse vaccinology and pan-genomic analysis showed potential to improve ELISA sensitivity and specificity for detecting Leptospira exposure in horses compared to current MAT gold standard
- •Selected antigens met antigenic criteria of antigenicity score ≥0.5, presence of B cell epitopes, and size between 10-275 kDa
- •Some identified antigens demonstrated potential for serovar-specific detection to improve identification of infecting Leptospira serovar
- •Study was limited by reliance on MAT as reference standard, geographic restriction of sera samples, and testing against only seven serovars