Question

Which one of the following answers is not one of Koch’s postulates on causality?

The organism must be observed in every case of disease.

The organism must be isolated and grown in pure culture.

The pure culture must, when inoculated into a susceptible animal, reproduce the disease.

The organism, must be observed in, and recovered from, the experimental animal.

The organism must produce a dose-response relationship.

Answer 1

Ans.

"The organism must produce a dose-response relationship" is not one of the Koch's postulates on causality.

The Koch's postulates on causality are -

1. the microorganism or other pathogen must be present in all cases of the disease.
2. 
   
3. the pathogen can be isolated from the diseased host and grown in pure culture.
4. 
   
5. the pathogen from the pure culture must cause the disease when inoculated into a healthy, susceptible laboratory animal.
6. 
   
7. the pathogen must be reisolated from the new host and shown to be the same as the originally inoculated pathogen.