Question

One of Koch's postulates states that the suspected causative organism should

• A. not grow in artificial media
• B. get cleared by the host immune system
• C. always be associated with other organisms and hence cannot be grown as pure culture
• D. be grown in pure culture

Hint:

Koch's postulates are fundamental in microbiology and disease causation studies, emphasizing the isolation and cultivation of pathogens in pure culture.

Answer 1

The Correct Option is D

Step 1: Understanding Koch's postulates.
Koch's postulates are a set of criteria used to establish a causative relationship between a microorganism and a disease. One key postulate requires that the microorganism can be isolated and grown in pure culture. This is essential to prove that the organism itself is responsible for the disease.

Step 2: Analyzing the options.
(A)not grow in artificial media: This is incorrect because Koch's postulates require the organism to be able to grow in artificial media.
(B)get cleared by the host immune system: This does not relate directly to Koch's postulates. The focus is on isolation and cultivation, not the immune system's role.
(C)always be associated with other organisms and hence cannot be grown as pure culture: This contradicts the requirement of being grown in pure culture.
(D)be grown in pure culture: Correct — Koch's postulates specifically state that the microorganism must be capable of being isolated and grown in pure culture.

Step 3: Conclusion.
The correct answer is (D)be grown in pure culture, as it aligns with one of Koch's essential postulates.