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. This bacterium has a unique waxy cell wall that makes it resistant to many common antibiotics, complicating treatment. Diagnosis typically involves skin tests, blood tests, or imaging studies like chest X-rays. Effective treatment usually requires a long course of specific antibiotics to fully eliminate the infection.