Complex sentence: Tuberculosis (MTB, TB) is an infectious disease usually caused by the bacterium "Mycobacterium tuberculosis", which generally affects the lungs, but can also affect other parts of the body.
Split into simpler sentences: Tuberculosis (MTB, TB) is an infectious disease usually caused by the bacterium "Mycobacterium tuberculosis". Tuberculosis generally affects the lungs, but can also affect other parts of the body.