Leptospira collagenase and LipL32 for antibody detection in leptospirosis

Various Leptospira components have been identified as candidate antigens for the detection of antibody to Leptospira. LipL32 is a Leptospira membrane protein which has been widely studied. The report of Leptospira wholegenome sequencing demonstrated that pathogenic Leptospira contained the nucleotide sequence (colA gene) coding for the collagenase. Expression of ColA protein and its enzymatic activity was demonstrated. In this study, cloned ColA protein, in comparison with LipL32, was used as an antigen for antibody detection. Thirty pairs of sera from human leptospirosis patients were tested. Sera from blood donors, and patients with scrub typhus and dengue virus infection (20 samples from each group) were tested for the specificity. All sera from leptospirosis patients tested in this study reacted with both ColA and LipL32 proteins. Sera from blood donors, patients with scrub typhus and dengue virus infection did not react with ColA protein. Data suggested that sensitivity and specificity of ColA protein for Leptospira antibody detection were 100%. In addition, ColA protein showed higher specificity than LipL32. Our data suggested that ColA protein could be another candidate antigen for antibody detection in leptospirosis diagnosis.