Mycobacteria are small, slow-growing aerobic rod-shaped bacteria. They have a complex, lipid-rich cell wall, for the so-called. Acid strength (i. E., They can not be after staining with carbol.fuchsin by acids again discolor) and their relative resistance to Gram stain is responsible. The most common mycobacterial infection is tuberculosis; others are leprosy and various, by ubiquitous mycobacteria (inter alia .: Mycobacterium avium complex) caused diseases.