Mycoplasmosis is caused by the Mycoplasma fermentans & Mycoplasma species. Mycoplasma species can infect a tick on its own but is most commonly seen as a co-infection with Borrelia species, like those that cause Lyme. This is because it is an opportunist organism that has a better chance of causing disease if the host is already co-infected with something else.
Mycoplasma fermentans is a common Mycoplasma species that is seen in ticks and will invade multiple cell types and trigger an immune response. The immune response is known to cause most of the damage and symptoms of infection.
Due to its structure and other characteristics, Mycoplasma species are resistant to many types of antibiotics.