Treponema pallidum, SEM

Scanning electron micrograph (SEM) of Treponema pallidum, Gram-negative, spirochete bacterium. Two spirochetes are located on two sperm heads. Treponena is an obligate human parasite and is the causative agent of syphilis. Research indicates that the organism is microaerophilic and requires low concentrations of oxygen. It is a spirochete, a helical to sinusoidal (spiral shaped, corkscrew shaped) bacterium with outer and cytoplasmic membranes, a thin peptidoglycan layer, and periplasmic flagella. T. pallidum initially causes an ulcer (chancre) to develop at the site of infection. Over time, as the organism moves through the body, it causes damage to vital organs. It is transmitted from one infected person to another and is usually spread through sexual contact. Complications include blindness, mental illness, neurological disorders, and even death. Magnification: x4,000 when shortest axis printed at 25 millimetres.