BACTERIES ET VIRUS RENDENT-ILS MALADES?
Comment prouver que la bactérie et le virus peuvent rendre un organisme malade?
Heinrich Hermann Robert Koch (1843–1910) is considered one of the founders of modern bacteriology; he created and improved laboratorytechnologies for isolating bacteria and also developed techniques forphotographing bacteria. His research led to the creation of Koch’s postulates, which consist of four principles
linking specific microorganisms to specific diseases. Koch’s postulates areas follows:
1-The microorganism must be found in abundance in all organisms suffering from the disease
but not found in healthy organisms.
2-The microorganism must be isolated from a diseased organism and grown in a pure culture.
3-The cultured microorganism should cause disease when introduced into a healthy organism.
4- The microorganism must be re-isolated from the now diseased experimental host which received the inoculation of the microorganisms and identified as identical to the original
specific causative agent.
If all four conditions are met, you have proven the infectious cause for aspecific set of symptoms. This is the onlyway to prove causation.
In 1937, Thomas Rivers modified Koch’s postulates in order to
determine the infectious nature of viruses. Rivers’ postulates are as follows:
1-The virus can be isolated from diseased hosts.
2-The virus can be cultivated in host cells.
3-Proof of filterabilitythe virus can be filtered from a medium that also contains bacteria.
4-The filtered virus will produce a comparable disease when the cultivated virus is used toinfect experimental animals.
5-The virus can be re-isolated from the infected experimental animal.
6-A specific immune response to the virus can be detected.
Please note that Rivers drops Koch’s first postulatethat’s because
many people suffering from “viral” illness do not harbor the offendingmicroorganism. Even with Koch’s first postulate missing, researchers havenot been able to prove that a specific virus causes a specific disease using
