Gel purified LipL32: a prospective antigen for detection of leptospirosis.

BACKGROUND: Leptospirosis, a zoonosis, is a re-emerging disease, affecting populations across the globe. However, the current methods of diagnosis are time- consuming, cumbersome, imprecise or expensive. AIM: To develop an assay for differential and early diagnosis of Leptospirosis. METHODS AND MATERIAL: IgG based ELISA for evaluation of three antigens, namely, a gel-purified recombinant protein (rLipL32), secreted proteins and whole organism sonicates of Leptospira spp. The antigens were evaluated using, rabbit polyclonal antiserum and human sera samples. RESULTS: Studies with a rabbit polyclonal antiserum indicated the utility of these antigens in differentiating Leptospira from other common pathogenic organisms. Evaluation of these antigens with fifteen representative human serum samples indicated gel-purified rLipL32 to be a potentially useful antigen for detection of leptospirosis. The results obtained with IgG ELISA were correlated with the results of microscopic agglutination test (MAT). CONCLUSION: Gel-purified rLipL32 is a valuable antigen for early and accurate diagnosis of leptospirosis. Further evaluation of this assay in field conditions and larger sera samples will indicate its suitability in case of an epidemic.