Never be afraid to ask - some of us "regulars" get lazy, and use abbreviations assuming everyone knows what we mean - that's our mistake. So, NTM is Non-tubercular mycobacteria. TB is probably the most common of the Mycobacteria that infect humans. When we say we have MAC, we mean mycobacteria avium complex - there are several versions that can infect us, probably the most usual is M. avium intercellulare (so some people say MAI) - then there are the M. abscessus, M. gordonae, M. hominum ...

I will be more careful with using jargon and initials when chatting with others, try to remember not everyone reading it knows our shorthand- thanks for the reminder.
Sue