Development of a recombinant protein based ELISA for the diagnosis of canine leptospirosis

Background Leptospirosis is an emergent zoonotic disease caused by pathogenic Leptospira spp., and humans are regarded as an accidental or dead-end host [1]. The global incidence of severe human leptospirosis was estimated to be approximately 500.000 cases worldwide, although this is likely an underestimate due to the lack of a reliable diagnostic test. Mortality ranges from 10 to > 50% for Weil’s disease or severe pulmonary hemorrhage syndrome (SPHS), respectively [2]. The microscopic agglutination test (MAT) is the standard test for this disease, however, it requires paired serum samples, is laborious, difficult to analyze and subjective [3]. Apart from the danger connected with rodents, which are the main vectors of leptospires, occurrence of the disease in dogs can generate a higher risk of infection for humans. Thus, a novel sensitive and specific serological test providing a rapid and secure diagnosis is urgently required for the laboratorial diagnosis of leptospirosis. In this study, 15 recombinant proteins from L. interrogans were expressed, purified and evaluated in an indirect ELISA using canine sera that were characterized by the MAT and a whole-cell Leptospira ELISA.