Development of an In-house Indirect ELISA Test as a Diagnostic Tool for Bovine Leptospirosis

Abstract

Background: Leptospirosis is one of the most common zoonotic diseases, which is caused by a Spiral shaped bacterium called Leptospira. The recommended diagnosis method is to perform microscopic agglutination test (MAT) which is both hazardous, due to using live bacteria, and time-consuming. As a result, many attempts have been recently made to develop other serological methods, such as ELISA. Objective: This study aimed to develop an indirect ELISA method using leptospiral whole antigens for diagnosing pathogenic Leptospira. Materials and Methods: In this study, four pathogenic serovars of Leptospira were used and cultured in selective culture medium. The cultured bacteria were sonicated and the extracted antigens were used as captured antigen in ELISA method. A total of 74 samples from bovine suspected to leptospirosis and 43 samples from healthy animals were examined by MAT method. Results: According to the study results, 42 samples (56.7%) out of 74 suspected ones were found positive while 32 ones (43.2%) were determined negative by MAT analysis. All of the 43 negative control samples were found negative after performing MAT. The sensitivity and specificity of ELISA, compared to those of MAT, were measured as 87.5% and 84.2%, respectively. Conclusion: Taking into account the high sensitivity and appropriate specificity of the developed indirect ELISA method, it was recommended that ELISA be employed as an accurate method for early and rapid diagnosis of bovine leptospirosis.