Characterization of recombinant flagellin B protein from Leptospira interrogans.

Symptoms of the early phase leptospirosis often are non-specific and can be a major problem in making a diagnosis of febrile illnesses. Rapid diagnosis of leptospirosis is of extreme importance, because antibiotic treatment provides greatest benefit when administered in early stage of the disease. Recombinant flagellin B (FlaB) gene (flaB) of Leptospira interrogans serovar Autumnalis strain Akiyami A was heterologously expressed and purified. The 35 kDa recombinant FlaB was 99% similar to the reference strain in GenBank. Rabbit polyclonal antirecombinant FlaB antibodies recognized using immunoblotting yeilded 35-36 kDa doublet from one saprophytic and eight pathogenic Leptospira serovars. Western blot assay showed that recombinant FlaB could distinguish leptospirosis from non-leptospirosis sera. This recombinant FlaB can be used in serodiagnosis of leptospirosis and identification of Leptospira spp.