Identification of pathogenic Leptospira species by conventional or real-time PCR and sequencing of the DNA gyrase subunit B encoding gene

Background  

Leptospira is the causative genus of the disease, leptospirosis. Species identification of pathogenic Leptospira in the past was generally performed by either DNA-DNA hybridisation or 16s rRNA gene sequencing. Both methods have inherent disadvantages such as the need for radio-labelled isotopes or significant homology between species. A conventional and real-time PCR amplification and sequencing method was developed for an alternate gene target: DNA gyrase subunit B (gyrB). Phylogenetic comparisons were undertaken between pathogenic Leptospira 16srRNA and gyrB genes using clustering and minimum evolution analysis. In addition 50 unidentified Leptospira isolates were characterised by gyrB sequencing and compared with conventional 16s rRNA sequencing.