@barbb, Hello. Here is some info for you in a nutshell. MAC is short for mycobacterium avium complex a.k.a. NTM (non-tuberculosis mycobacterium) mac is a cousin to T.B. only it is not contagious like t.b. People with bronchiectasis are more prone to developing an infection from this bacteria than people without .That is due to the structural changes in the lung tissue that bronchiectasis causes and it traps bacteria. There is a lot of info in our older posts. You can go to the Discussion Board on the group's homepage and scroll through the topics. If you go to the magnifying glass at the top of this page and click on it, a box will appear. Type in @kateman and that member's posts will pop up. She has p Please let me know if you have trouble navigating this site.osted lots of helpful info. Same with my name @windwalker.