Mycobacterium tuberculosis (M. tuberculosis) is a bacterium that causes tuberculosis (TB) in humans. TB is a disease that primarily affects the lungs, although it can attack other parts of the body. It spreads much like a cold or the flu — through the expelled airborne droplets from a person with infectious TB. Mycobacterium tuberculosis is a human pathogen that has had a staggering global impact. Its origins are ancient. Spinal deformities typical of those resulting from M. tuberculosis disease have been found in human remains as far apart as Peru and Egypt and dating from at least 5000 BCE