These are known as Atypical Mycobacteria. Some of them are completely harmless and can be found in soil or some water supplies. Others are usually harmless, but can cause serious disease in patients whose immune system is not working properly. This disease is then know as Atypical tuberculosis . You get infected with M.Bovis from unpasteurised milk or contact with infected cattle.
M. tuberculosis is spread by coughing.
You have to be in close contact with a patient with TB for some time before you are likely to catch it from them. If you live with someone who has open TB and are particularly if you are not protected by a BCG vaccination , your risk of catching TB is high. I thought TB was a rare disease now. It became much less common as people were better fed with better housing. This was happening even before antibiotics started to be available in the late 1940's.