Mycobacterium tuberculosis is a type of bacteria that causes tuberculosis (TB), a serious infectious disease primarily affecting the lungs. It spreads through the air when an infected person coughs or sneezes, releasing tiny droplets containing the bacteria. TB can also affect other parts of the body, such as the kidneys, spine, and brain. The bacteria are known for their thick, waxy cell wall, which makes them resistant to many common antibiotics. Diagnosis typically involves a skin test or blood test, and treatment usually requires a long course of specific antibiotics to effectively eliminate the infection and prevent its spread.