Susceptibility to Penicillin G and Ceftriaxone in Three Clinical Treponema pallidum Isolates is not Altered by Amino Acid Polymorphisms in the Tp0705 Penicillin Binding Protein

We demonstrated no differences in susceptibility to penicillin G and ceftriaxone in three modern T. pallidum isolates (UW244B, UW249B, and UW330B), each carrying a variant of the penicillin-binding protein (PBP) Tp0705. This suggests that these polymorphisms should not be a reason for concern when {beta}-lactams are prescribed for syphilis treatment. SUMMARYWe report that three modern Treponema pallidum isolates carrying amino acid polymorphisms at positions 506, 625, and 708 of the penicillin-binding protein (PBP) Tp0705 are equally susceptible to penicillin G and ceftriaxone.