Lyme disease - Borrelia burgdorferi organism

Lyme disease is caused when a person is bitten by a tick infected with bacteria called Borrelia burgdorferi. These bacteria are known as spirochetes because of their long, corkscrew shape. This photograph shows the typical corkscrew appearance of a spirochete. Other types of spirochete bacteria cause diseases such as syphilis and leptospirosis. After a person is bitten by an infected tick, the bacteria spread from the skin through the bloodstream to other organs. The skin, nervous system, joints, heart, and eyes are most often affected. (Image courtesy of the Centers for Disease Control and Prevention.)