flaB-polymerase chain reaction (flaB-PCR) and its restriction fragment length polymorphism (RFLP) analysis are an efficient tool for detection and identification of Leptospira spp.

For establishment of a rapid-identification method of Leptospira species, a flaB gene of Leptospira was investigated and the following results were obtained. 1) HaeIII- or HindIII-restriction fragment length polymorphism (RFLP) of polymerase chain reaction (PCR) products (793 bp) of flaB gene was effectual for the classification of species of Leptospira, 2) Twenty cells of Leptospira in 1 mi of coagulated blood and 100 cells of Leptospira in 1 mi of anti-coagulated blood could be detected by flaB-PCR. These results suggested that PCR-RFLP based on the flaB gene was an efficient tool for rapid detection and identification of species of infected Leptospira from clinical specimens.