Which of the following would meet the criteria of one of Koch's postulates?
a. The test subject develops symptoms within a week of receiving the initial dose.
b. The test subject does not develop the same signs and symptoms of a disease as the original diseased individual.
c. The test subject was found to have the same pathogen as the original diseased individual when the pathogen was isolated.
d. The disease is found in healthy individuals.
e. Diseased individuals test positive for the suspected pathogen.
To determine which of the options meets the criteria of one of Koch's postulates, we need to understand what Koch's postulates are and then evaluate each option against those criteria.
Koch's postulates are a set of four criteria used to demonstrate the causal relationship between a specific pathogen and a specific disease. These postulates were developed by the German physician Robert Koch in the late 19th century. Here are Koch's postulates:
1. The microorganism must be present in every case of the disease: This means that the specific pathogen being studied should be found in every individual who has the disease.
2. The pathogen must be isolated from the diseased individual and grown in pure culture: The pathogen should be isolated and grown in a laboratory to establish a pure culture.
3. The pure culture of the pathogen should cause the same disease when inoculated into a healthy, susceptible individual: To prove that the pathogen is the cause of the disease, it should be able to reproduce the same signs and symptoms of the disease in a healthy individual when inoculated with the pathogen.
4. The same pathogen must be re-isolated from the newly infected individual: The pathogen must be isolated again from the newly infected individual to confirm its presence and match it to the original pathogen.
Now, let's evaluate each option against Koch's postulates:
a. The test subject develops symptoms within a week of receiving the initial dose.
This option does not satisfy any of Koch's postulates because it doesn't address the presence or isolation of the pathogen.
b. The test subject does not develop the same signs and symptoms of a disease as the original diseased individual.
This option does not satisfy Koch's postulates because it doesn't mention the presence or isolation of the pathogen.
c. The test subject was found to have the same pathogen as the original diseased individual when the pathogen was isolated.
This option satisfies Koch's postulates. It establishes the presence of the pathogen in the test subject and its isolation, fulfilling postulates 1 and 2.
d. The disease is found in healthy individuals.
This option does not satisfy Koch's postulates because it doesn't address the presence or isolation of the pathogen.
e. Diseased individuals test positive for the suspected pathogen.
This option partially satisfies Koch's postulates. It addresses the presence of the pathogen in diseased individuals, but it doesn't mention the isolation and re-isolation of the pathogen, which are crucial to fulfill postulates 2 and 4.
In conclusion, only option c, "The test subject was found to have the same pathogen as the original diseased individual when the pathogen was isolated," meets the criteria of one of Koch's postulates.