Robert Koch: Nobel laureate and controversial figure in tuberculin research.

Tuberculosis has been a major cause of death for centuries. Likewise, anthrax has posed a deadly threat to both farm animals and humans and today poses a threat as a weapon of biological warfare. Cholera, which wreaked havoc in the East and threatened to enter Europe, also posed a deadly threat. The causes of these diseases remained mysteries for centuries. Nobel laureate Robert Koch (1843-1910), often called the founder of medical bacteriology, is credited with discovering the tubercle bacillus, Mycobacterium tuberculosis; with demonstrating for the first time in history the life cycle of the anthrax bacillus under controlled in vitro conditions; and with identifying Vibrio cholorae as the cause of cholera. In later life, he also was at the center of several controversies. This article provides a brief summary of Koch's exploration into bacteriology and, especially, his experience with tuberculosis and the controversies that developed in the latter part of his life, as well as his childhood and early adult years and the development of his now well-known "postulates."