I was interested in knowing how long the mycoplasma that causes Upper Respiratory Tract Disease (URTD) in desert tortoises can live outside the host, so I asked the question of GOOGLE. This was the first response. It is about 6 years old, but is a VERY interesting read:
http://www.tortoise.org/archives/brown1.html
Yvonne
http://www.tortoise.org/archives/brown1.html
Yvonne