Treponema pallidum Physiology Strictly human pathogen -slow replication( time of replication =30 hrs Treponema pallidum testis infected rabbit Too thin to be visible in light microscope( darkfield, fluorescence Do not survive well outside of host Not cultivable Darkfield Microscopy of Treponema pallidum9 Treponema pallidum • Physiology -Strictly human pathogen -Slow replication (time of replication = 30 hrs) -Too thin to be visible in light microscope ( darkfield, fluorescence) -Do not survive well outside of host -Not cultivable Treponema pallidum - testis infected rabbit Darkfield Microscopy of Treponema pallidum