Tuberculosis can be fought with antibiotics that need to be taken for months. It is important that patients continue to take the drugs even when they feel better. If they stop before the infection is cleared up, they can spread the disease and encourage the tuberculosis bacteria to become resistant to the drugs.
Still, the bacteria is difficult to eliminate because it has a tough cell wall made of lipids and mycolic acid. This allows the organism to withstand some disinfectants and to survive being dried out for some weeks.