No, I would definitely not start treatment based off of one positive sputum culture. First you need to know what bacteria you have before you can start treatment as there are different treatment plans. What does your CT scan show? Do you have a Cavity? Many doctors will do a watch and wait before starting treatments. They will suggest doing Airway clearance to see if you can clear it on your own. It all depends on what you CT scan shows, your colony count, and what type of bacteria you have. Try to find a DR that is familiar with MAC. I was diagnosed in 2/20 and have never been treated. Hope this helps!