Which group of bacteria that can cause lyme disease and syphilis?

The group of bacteria that can cause Lyme disease and syphilis includes spirochetes. Specifically, Borrelia burgdorferi is responsible for Lyme disease, while Treponema pallidum is the causative agent of syphilis. Both are distinct species within the spirochete family and are transmitted through different vectors; Lyme disease is primarily spread by ticks, while syphilis is transmitted through sexual contact.