Research progress on ultrastructure of Treponema pallidum subspecies pallidum

The ultrastructure of Treponema pallidum, the causative pathogen of syphilis, remains unclarified because of the difficulty of long-term culture in vitro. However, research on the ultrastructure of T. pallidum has made great progress in recent years with the success of long-term culture of T. pallidum in vitro and the development of gene sequencing technology and electron microscopy. This review summarizes the research progress on the ultrastructure of T. pallidum.