Final answer:
Treponema pallidum is a pathogenic bacteria that causes syphilis, a sexually transmitted infection. It is a spiral-shaped spirochete bacteria. Different microscopic techniques can be used to observe Treponema pallidum.
Step-by-step explanation:
Treponema pallidum is a pathogenic bacteria that causes the sexually transmitted infection known as syphilis. It is a spirochete, a type of bacteria that is spiral-shaped. Syphilis is one of the most prevalent sexually transmitted bacterial infections in the United States. Treponema pallidum can be observed using darkfield microscopy, silver stain microscopy, or immunofluorescence microscopy.