Koch's postulates

Definition

Koch's postulates are a set of four criteria established by Robert Koch to identify the causative agent of a particular disease. These postulates are used to establish a cause-and-effect relationship between a microbe and a disease.

5 Must Know Facts For Your Next Test

1. The four postulates include: presence in diseased individuals, isolation and growth in pure culture, reproduction of disease when introduced to a healthy host, and re-isolation from the experimentally infected host.
2. Koch's postulates were pivotal in confirming that specific bacteria cause specific diseases.
3. They were formulated in the late 19th century and initially used to identify the causative agents of tuberculosis and anthrax.
4. While highly influential, Koch's postulates have limitations, especially for viruses and obligate intracellular pathogens that cannot be cultured easily.
5. Modern molecular techniques sometimes replace traditional methods but still rely on the principles behind Koch’s postulates.

Review Questions

Related terms

Germ Theory of Disease: The theory that microorganisms are the cause of many diseases.

Pathogen: An organism or agent that causes disease.

Pure Culture: A laboratory culture containing only one species of microorganism.