Molecular cloning and characterization of a novel leptospiral lipoprotein with OmpA domain

A novel antigenic protein of pathogenic Leptospira, Loa22, was identified by using the PhoA fusion method followed by immunoblotting with convalescent mouse sera. Loa22 was shown to be a lipoprotein having a C-terminal OmpA consensus domain. Loa22 was detected among pathogenic leptospires but not among non-pathogenic leptospires, suggesting the possible involvement of this protein in virulence. The results of three different experiments suggested that Loa22 is located in the outer membrane and a small portion is exposed on the cell surface. Thus, Loa22 may be a candidate for a novel vaccine against infection with pathogenic leptospires.