Borelia
Borrelia is a genus of spirochete bacteria that are responsible for causing the disease known as Lyme disease, or Lyme borreliosis. These bacteria are transmitted to humans and animals through the bite of infected ticks, primarily from the Ixodes genus. Borrelia burgdorferi is the most well-known species, causing Lyme disease in North America and Europe. Other species, such as Borrelia afzelii and Borrelia garinii, are also significant contributors to Lyme disease in Eurasia.
The spirochetes are characterized by their spiral shape, which allows them to move effectively through tissues.