A Treponema pallidum triplet antigen construct is disclosed which includes three Treponema pallidum antigens (TP15, TP17, and TP47), as well as a ten amino acid leader sequence (tag 261) and human copper zinc superoxide dismutase (hSOD). This construct is optimized for in vitro diagnosis of syphilis infection. Plasmids containing DNA encoding the triplet antigen, host cells, production methods, detection methods, and kits are also disclosed.
1. A Treponema pallidum triplet antigen with a sequence consisting of the amino acid sequence of SEQ ID NO:9.
2. The Treponema pallidum triplet antigen of claim 1 labeled with a detectable marker.
3. The Treponema pallidum triplet antigen of claim 2 wherein the detectable marker is horseradish peroxidase.
4. A method of detecting the presence of Treponema pallidum antibodies in a sample, the method comprising:
contacting the sample with the Treponema pallidum triplet antigen of claim 1 , wherein Treponema pallidum antibodies present in the sample bind to the Treponema pallidum triplet antigen forming an antibody/antigen complex; and
detecting the antibody/antigen complex, thereby detecting the presence of Treponema pallidum antibodies.
5. The method of claim 4 wherein the Treponema pallidum triplet antigen is immobilized on a solid support.
6. The method of claim 4 wherein detecting the antibody/antigen complex comprises: contacting the antibody/antigen complex with a second Treponema pallidum triplet antigen, wherein the second Treponema pallidum triplet antigen is the Treponema pallidum triplet antigen of claim 1 labeled with a detectable marker and wherein the second Treponema pallidum triplet antigen binds to the antibody present in the antibody/antigen complex forming an antigen/antibody/labeled antigen complex; and detecting the antigen/antibody/labeled antigen complex, thereby detecting the presence of Treponema pallidum antibodies.
7. The method of claim 4 wherein detecting the antibody/antigen complex comprises:
contacting the antibody/antigen complex with labeled anti-human antibody, wherein the labeled anti-human antibody binds to the antibody present in the antibody/antigen complex forming an antigen/antibody/labeled anti-antibody complex; and
detecting the antigen/antibody/labeled anti-antibody complex, thereby detecting the presence of Treponema pallidum antibodies.
8. A component of a kit for detection of Treponema pallidum antibodies, the component comprising the Treponema pallidum triplet antigen of claim 1 .