Detection of pathogenic Leptospira spp. By polymerase chain reaction reaction (PCR) targeting ligB gene

Background: Leptospirosis is an emerging infectious disease and is considered to be the most widespread zoonotic disease in the world. LigB is an immunogenic outer membrane protein. The leptospiral ligB gene expressed only in pathogenic Leptospira spp. The aim of this study was molecular diagnosis of pathogen Leptospires by PCR based on ligB gene. Materials and Methods: Five pathogenic Leptospires: L. canicola, L. grippotyphosa, L. pomona, L. icterohaemorrhagiae, L. serjoe hardjo and saprophytic L. biflexa were used in this study. The bacteria were inoculated into the selective culture medium and extraction of the genomic DNA was performed by standard Phenol-Chlorophorm method. The specific primers for proliferation of ligB gene were designed. The specificity and sensitivity of PCR method was evaluated. Results: PCR product was 1041bp which indicated proliferation of ligB gene which was supported using electrophoresis. The PCR based on ligB gene detected all pathogenic reference serovars of Leptospira spp. tested. No PCR products were amplified from the non-pathogenic L. biflexa. Conclusion: Considering the spread of Leptosperosis in moderate and hot areas which have high rate of fall, a proper molecular diagnostic test with high specificity and sensitivity such as PCR is essential. PCR assay with high specificity and sensitivity may prove to be a rapid method for diagnosing acute leptospirosis. The results suggested that the PCR based on ligB gene can be used for detection of pathogenic leptospires.