AFB denotes Acid-fast bacteria, also called acid-fast bacilli. These are a group of bacteria sharing the property of acid fastness, that is the physical ability to resist decolorization by acids during staining procedures. This unique feature serves as a distinguishing ability in classifying and detecting acid-fast bacteria like Mycobacteria.
MGIT is short for Mycobacteria Growth Indicator Tube. It is a liquid broth medium that is known to yield better recovery and faster growth of mycobacteria and a system that determines if AFB will grow in the presence of mycobacterium drugs or not.