Related Experiment Video
Updated: May 9, 2026
Procedures for In Vitro Cultivation of Treponema pallidum, the Syphilis Spirochete
Published on: January 24, 2025
Molecular subtyping of Treponema pallidum in Paris, France
Philippe Alain Grange1, Caroline Allix-Beguec, Johan Chanal
1Laboratoire de Recherche en Dermatologie, EA 1833, Centre National de Référence Syphilis, Faculté de Médecine, Université Sorbonne Paris Descartes, Paris, France.
Abstract:
Two major Treponema pallidum subtypes, 14 d/g and 14 d/f, were identified in a population of 119 patients with syphilis in Paris, France, characterized by a high proportion of men who have sex with men. A new subtype named 11 q/j was characterized, and a reinfection case was determined in 1 patient having consecuitve syphilis infection at 19-month interval.
Insights
Two Treponema pallidum subtypes, 14 d/g and 14 d/f, were found in Paris syphilis patients. A new subtype, 11 q/j, was identified, along with a reinfection case.
Area of Science:
- Infectious Diseases
- Microbiology
- Epidemiology
Background:
- Syphilis remains a significant public health concern globally.
- Treponema pallidum subtypes are crucial for understanding transmission dynamics and disease progression.
- The epidemiology of syphilis, particularly among men who have sex with men (MSM), requires ongoing surveillance.
Purpose of the Study:
- To characterize Treponema pallidum subtypes in a Parisian syphilis patient cohort.
- To identify novel subtypes and document reinfection cases.
- To contribute to the understanding of syphilis epidemiology in a high-prevalence population.
Main Methods:
- Molecular typing of Treponema pallidum isolates from 119 syphilis patients.
- Analysis of specific genetic markers to differentiate subtypes.
- Case investigation to identify and confirm reinfection.
Main Results:
- Identification of two major Treponema pallidum subtypes: 14 d/g and 14 d/f.
- Characterization of a newly identified subtype, designated 11 q/j.
- Confirmation of a syphilis reinfection case in a patient with a 19-month interval between infections.
Conclusions:
- The study identified key Treponema pallidum subtypes circulating in Paris.
- The emergence of a new subtype highlights the evolving nature of the pathogen.
- Documenting reinfection underscores the importance of sustained prevention and treatment efforts.
