Hi Sue. You did a beautiful job in spelling out in "layman" terms about the process in sputum testing. I've been dealing with MAC for almost 3 years now. I'm currently on oral Levofloxacin to try and treat Pseudomonas yet again. This has been the 5th time in three years. If this does not work I'll probably have to again do the 28 days of Tobramycin. I am on my third pulmonary doctor. First one immediately put me on the Big 3 for positive MAC. After 6 weeks I was taken off because I was not able to tolerate them. The doctor said he was probable not able to help me. Instead of doing a referral he just "quit" me. Through this forum another MAC sufferer told me of a doctor she found. He was 3 hours away but I got an appt. What a God send this man was. He guided me through my off and on infections and last summer I asked if he had someone closer to me to continue to manage my situation. He did recommend someone within 1 1/2 hrs away. I had been doing well up until the most recent positive pseudonymous report. One question I do have and I did present it to my current pulmonary doc... When sputum was tested at Emory the Pseudomonas was classified 1+ thru 4+. 4+ was the worse. So I asked my current doc how my sputum was classified at U. at B'ham he just said something like, "we don't rate that way." Any idea on what he means? Also he did say when he treats Pseudomonas using Tobramycin he usually does two weeks on and two weeks off. Is that schedule what you've experienced. I thought I'd seen on this forum that they would do one month on and one month off. It seems I've read that you have a lot of experience with the alternating treatments. Love your insight. So helpful. Faye