Which scientist identified the tuberculosis bacterium in 1882?

Robert Koch identified the tuberculosis bacterium in 1882. On 24 March that year, Koch announced that he had found the organism responsible for tuberculosis, now called Mycobacterium tuberculosis. He used staining and microscopy to demonstrate the bacterium in diseased tissue and then described methods for growing it.

Tuberculosis was one of the leading causes of death in nineteenth-century Europe, and its cause had long been debated. Koch’s work provided strong evidence that a specific microorganism caused the disease and helped establish bacteriology as a rigorous medical science. His findings also supported the wider use of Koch’s postulates, criteria for linking a microbe with a disease.

Koch did not discover a tuberculosis vaccine or an effective cure. His contribution was identifying the pathogen and developing laboratory methods for studying it. World Tuberculosis Day is held on 24 March to commemorate the 1882 announcement. Koch received the 1905 Nobel Prize in Physiology or Medicine for his investigations and discoveries concerning tuberculosis.