Compositions and methods for detecting treponema pallidum

Abstract

Methods for the specific and highly sensitive detection of Treponema pallidum infection comprising the use of specific antigenic proteins and peptides unique to Treponema pallidum are provided. In particular, detection assays based on recognition of acidic repeat protein are provided. The methods of the present invention are useful for detection of primary syphilis at early stages of infection. In addition, the methods and compositions disclosed herein are directed to the differential detection of specific Treponema infections enabling the identification of causative agents for specific Treponema disease states: syphilis ( Treponema pallidum subspecies pallidum ), yaws ( Treponema pallidum subspecies pertenue CDC-1 or CDC-2 strain), and bejel ( Treponema pallidum subspecies endemicum ).

1 . An isolated polypeptide comprising:
 (i) an N-terminal region having an amino acid sequence set forth as residues 1-126 of SEQ ID NO: 20;   (ii) a region comprising 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 or 14 repeat sequences, wherein the repeat sequences are Type I repeats, Type II repeats, Type III repeats, or a combination thereof; and   (iii) a C-terminal region having an amino acid sequence set forth as residues 407-547 of SEQ ID NO: 20.   
     
     
         2 . The isolated polypeptide of  claim 1 , wherein the repeat sequences are each 20 amino acids in length. 
     
     
         3 . The isolated polypeptide of  claim 1 , comprising 4 repeat sequences. 
     
     
         4 . The isolated polypeptide of  claim 1 , comprising 6 repeat sequences. 
     
     
         5 . The isolated polypeptide of  claim 1 , comprising 8 repeat sequences. 
     
     
         6 . The isolated polypeptide of  claim 1 , comprising 14 repeat sequences. 
     
     
         7 . The isolated polypeptide of  claim 1 , comprising at least one Type II repeat. 
     
     
         8 . The isolated polypeptide of  claim 7 , comprising 2, 3, 4, 5, 6 or 7 Type II repeats. 
     
     
         9 . The isolated polypeptide of  claim 1 , comprising the amino acid sequence of residues 128-407 of SEQ ID NO: 20. 
     
     
         10 . The isolated polypeptide of  claim 1 , comprising the amino acid sequence of residues 168-187 of SEQ ID NO: 20. 
     
     
         11 . The isolated polypeptide of  claim 1 , comprising at least one Type I repeat which consists of the amino acid sequence set forth as amino acids 127-146 of SEQ ID NO: 20. 
     
     
         12 . The isolated polypeptide of  claim 1 , comprising at least one Type II repeat which consists of the amino acid sequence set forth as amino acids 167-186 of SEQ ID NO: 20. 
     
     
         13 . The isolated polypeptide of  claim 1 , comprising at least one Type III repeat which consists of the amino acid sequence set forth as amino acids 387-406 of SEQ ID NO: 20. 
     
     
         14 . An isolated polypeptide comprising an amino acid sequence having at least 90% sequence identity to the sequence set forth in SEQ ID NO: 20, wherein the polypeptide is reactive with  Treponema pallidum  immune serum. 
     
     
         15 . The isolated polypeptide of  claim 14 , wherein the amino acid sequence has at least 95% sequence identity to the sequence set forth in SEQ ID NO: 20. 
     
     
         16 . The isolated polypeptide of  claim 14 , wherein the amino acid sequence has at least 98% sequence identity to the sequence set forth in SEQ ID NO: 20.