Clonal isolates of Treponema pallidum subsp. pallidum Nichols provide evidence for the occurrence of microevolution during experimental rabbit infection and in vitro culture.

ABSTRACT: The recent development of a system for long-term in vitro culture of the syphilis spirochete, Treponema pallidum subsp. pallidum, has introduced the possibility of detailed genetic analysis of this bacterium. In this study, the in vitro culture system was used to isolate and characterize clonal populations of T. pallidum subsp. pallidum Nichols, the most widely studied strain. In limiting dilutions experiments, it was possible to establish cultures with inocula as low as 0.5 T. pallidum per well despite the long generation time (~35 to 40 hours) of this organism. Six Nichols strain clones isolated by limiting dilution were characterized in detail. All clones exhibited indistinguishable morphology and motility, highly similar in vitro multiplication rates, and comparable infectivity in the

SUBMITTER: Edmondson DG 

PROVIDER: S-EPMC10013896 | biostudies-literature | 2023

REPOSITORIES: biostudies-literature