Difference between revisions of "Koch's postulates"
| Line 4: | Line 4: | ||
===Epidemiological association=== | ===Epidemiological association=== | ||
| − | The suspected cause must be strongly associated with the disease. | + | The suspected cause must be strongly associated with the disease. |
| + | The molecular version of this postulate states that an epidemiological association exists between presence of a trait and virulence, that a specific mutation be constructed to inhibit the function resulting in decrease | ||
| + | in virulence, and finally that the mutation be complemented in trans with only the wild-type allele of the | ||
| + | mutated gene provided on a recombinant plasmid. | ||
===Isolation=== | ===Isolation=== | ||
Revision as of 20:37, January 8, 2009
Koch's postulates are a set of broad principles laid out by Robert Koch in the 1880's. They are the basic criteria for determining what is and is not an infectious disease in plants, animals, and humans. Because they are at the level of philosophy of science, they can be applied to viral, bacterial, or parasite-caused infection theories. Though aspects of the principles were not original, Robert Koch provided an experimental basis for these principles that was very convincing to the scientists of his day.
The Postulates
Epidemiological association
The suspected cause must be strongly associated with the disease. The molecular version of this postulate states that an epidemiological association exists between presence of a trait and virulence, that a specific mutation be constructed to inhibit the function resulting in decrease in virulence, and finally that the mutation be complemented in trans with only the wild-type allele of the mutated gene provided on a recombinant plasmid.
Isolation
The suspected pathogen can be isolated - and propagated - outside the host.
Transmission Pathogenesis
Transfer of the suspected pathogen to an uninfected host, man or animal, produces the disease in that host.