Susceptibility of Treponema pallidum to host-derived antimicrobial peptides

Peptides. 2003 Nov;24(11):1741-6. doi: 10.1016/j.peptides.2003.07.026.


LL-37 displays potent broad-spectrum activity against a number of pathogenic bacteria and is the only cathelicidin thus far identified in humans. In this study, we examined the capacity of human LL-37 and the similar CAP-18-derived peptide from rabbits to exert antimicrobial activity against the causative agent of syphilis, Treponema pallidum. We found that both peptides, as well as a truncated version of human LL-37 that contains its bactericidal domain, could exert rapid, but salt-sensitive antimicrobial activity against T. pallidum. Infectivity of T. pallidum in a rabbit model could effectively be blocked with the synthetic truncated LL-37-derived peptide WS22-N-amide.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Antimicrobial Cationic Peptides / pharmacology*
  • Humans
  • Microbial Sensitivity Tests
  • Peptide Fragments / pharmacology
  • Rabbits
  • Syphilis / metabolism*
  • Syphilis / microbiology*
  • Treponema pallidum / drug effects*
  • Treponema pallidum / physiology


  • Antimicrobial Cationic Peptides
  • Peptide Fragments
  • WS22-N-amide
  • CAP18 lipopolysaccharide-binding protein