Use of the Coding Region of Leptospira Sp. LigB C-terminus as a Marker for Diagnostics of Animal Leptospirosis

Abstract BackgroundThe causal agent of leptospirosis, pathogenic strains of the genus Leptospira spp., has Outer Membrane Proteins (OMPs) on its surface which play a fundamental role in infection and pathogenesis. Studies on the genome showed that the LigB protein gene is conserved in different pathogenic species. MethodsThe aim of this work was to propose a new end point PCR based on the amplification of the LigB C-Terminal coding region (ligb-ct), never used before and conserved among pathogenic Leptospira spp. Eighteen reference pathogenic, 2 intermediate and 2 no-pathogenic strains of Leptospira spp. were used. DNA from 10 other microorganism species were included in this study to determine the analytical specificity. ResultsWe obtained 100% positivity for pathogenic Leptospira strains. We found no cross-reaction with intermediate and non-pathogenic strains or with other microorganisms, highlighting a high analytical specificity. Analytical sensitivity estimated on clinical samples was higher on serum than blood and urine (6-9 x 102 lept/ml and 6-9 x 105 and 6-9 x 106 leptospires/ml, respectively). Multiple sequence alignment of this region in positive Leptospira species confirmed a high degree of conservation, with only a few single nucleotide polymorphisms. Conclusion To the best of our knowledge, the LigB C-Terminal coding region has not been previously used for molecular diagnostic and could be used for early diagnosis of leptospirosis.