Medical illustration of tuberculosis. Tuberculosis, MTB, or TB (short for tubercle bacillus) is a common, and in many cases lethal, infectious disease caused by various strains of mycobacteria, usually Mycobacterium tuberculosis. Treatment of TB uses antibiotics to kill the bacteria. Effective TB treatment is difficult, due to the unusual structure and chemical composition of the mycobacterial cell wall, which hinders the entry of drugs and makes many antibiotics ineffective. According to the Centers for Disease Control and Prevention, more than two million people in the United States get infections that are resistant to antibiotics and at least 23,000 people die as a result. Over-prescription of antibiotics leads to antibiotic-resistant germs.