Mycobacterium abscessus is a rapidly growing, non-tuberculous mycobacteria which is pathogenic for humans. It is commonly associated with contaminated traumatic skin wounds and with post-surgical soft tissue infections, in addition to being one of the mycobacteria most often isolated from cystic fibrosis patients. It is very resistant to common antimicrobial agents, which makes it difficult to treat. It is ubiquitously present in natural waters, decaying vegetation, sewage water, as well as in drinking water tanks and municipal tap water. Nosocomial outbreaks/pseudooutbreaks of M. abscessus have been described in connection with automated endoscope washers and in hospital water supplies. This strain, also known as CIP 104536, is the type strain and the first rapid-growth pathogenic mycobacterium to be sequenced, and will give important comparative information (adapted from PubMed 16725007).

Mycobacteria have an unusual outer membrane approximately 8nm thick, despite being considered Gram-positive. The outer membrane and the mycolic acid-arabinoglactan-peptidoglycan polymer form the cell wall, which constitutes an efficient permeability barrier in conjunction with the cell inner membrane.