Standardization and validation of an indirect ELISA based on the extraction of proteins from Leptospira spp. as an antigen for the diagnosis of canine leptospirosis

ABSTRACT

Leptospirosis is an important zoonosis. The World Health Organization recommends the use of microscopic soroagglutination in the diagnosis of the disease. However, this is a time-consuming technique that offers a risk of contamination to the performer and requires a trained professional. The indirect enzyme-linked immunosorbent assay (ELISA) test presents less risk, is faster, and has lower cost benefit for high sampling. In view of the advantages of using the test, and the importance of the development of techniques that facilitate and make the diagnosis more efficient, the objective of this study was to standardize an indirect ELISA technique using an immunogenic protein of Leptospira spp. for the diagnosis of canine leptospirosis. The standardized test obtained a cut off of 0.314, 76% of sensitivity, 34% of specificity, 53.52% of positive predictive value, 58.62 of negative predictive value, and 55% of accuracy. The protein extraction technique was efficient for antigen production, and the standardized test can be used in the diagnosis of canine leptospirosis.

Keywords
leptospirosis; indirect ELISA; microscopic agglutination test; diagnostic immunology