syphilis is caused by treponema pallidum, a species of spiral-d bacteria. over blurred organic background

bacillus background bacteria bacterium biology blurred caused chancre contagious dermatology dermatovenerology disease epidemic focus health herpes human ill illness infection infectious medical medicine micro microbe microbiology microscope microscopic monogamy neurosyphilis organ organic organism pallidum pathogen pathology penicillin rendering research selective sex sexual sexuality sexually sick sickness species spiralshaped std syphilis transmissible transmitted treponema veneral