title: Electron microscopy of Treponema pallidum occurring in a human primary lesion.
mesh_terms: D000328:Adult; D006801:Humans; D008297:Male; D008854:Microscopy, Electron; D012507:Sarcoidosis / Q000150:complications; D013591:Syphilis, Cutaneous / Q000150:complications / Q000382:microbiology*; D014210:Treponema pallidum / Q000166:cytology*