I was testing positive for over a year for mycobacteria Abcessus which I guess is the bad kind more of a fast grower. Then I tested negative for the last couple of years. I went to the mayo and they said I could start antibiotics but my CT scan wasn't bad enough if I wasn't ready. They wanted me to start on different Iv's to start with if so did. Im glad I didn't go on them since I started to test negative after that. I hadn't heard about the 40-60 spontaneous conversions. I know my dr said not to worry unless three tests came back positive though. I did have about 7 come back positive in a row.
Glad your doing well now!