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bioRxiv · 10.1101/2025.10.14.682455

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

Tantalo, L. C.·Chamakuri, K. D.·Greninger, A. L.·Lieberman, N. A. P.·Giacani, L.
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Abstract

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.

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Tantalo, L. C., Chamakuri, K. D., Greninger, A. L., Lieberman, N. A. P., Giacani, L.. 2025-10-15. 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. https://doi.org/10.1101/2025.10.14.682455

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