Definitions for "Koch's Postulates"
A set of postulates that must be met to prove that a particular bacterial pathogen causes a particular disease (Lecture: The Bacterial Cell: Structure, Function, Growth, and Gene Regulation II, 1/29/02)
Criteria proposed by Koch for proving the pathogenicity of an organism; (1) the suspected causal organism must be constantly associated with the disease; (2) it must be isolated and grown in pure culture; (3) when inoculated into a healthy plant it must reproduce the original disease.
to establish the specificity of a pathogenic microorganism, it must be present in all cases of the disease, inoculations of its pure cultures must produce disease in animals, and from these it must be again obtained and be propagated in pure culture.