## **Core Concept**
Bordetella pertussis, the causative organism of whooping cough, requires special culture media for isolation due to its fastidious nature. The organism needs specific nutrients and conditions to grow.

## **Why the Correct Answer is Right**
The correct answer, **Bordet-Gengou medium**, is specifically designed for the isolation of *Bordetella pertussis*. This medium contains blood, glycerol, and salt, along with other supplements that support the growth of *B. pertussis*. The medium's composition helps in providing the necessary nutrients for the growth of this fastidious organism.

## **Why Each Wrong Option is Incorrect**
- **Option A:** This option is incorrect because it does not specify a medium commonly associated with *B. pertussis* isolation.
- **Option C:** This option is incorrect as it does not accurately represent the medium used for isolating *B. pertussis*.
- **Option D:** This option is incorrect because it also does not accurately represent the specific medium used for the isolation of *B. pertussis*.

## **Clinical Pearl / High-Yield Fact**
A key point to remember is that *Bordetella pertussis* culture is often replaced by PCR (Polymerase Chain Reaction) for diagnosis due to the fastidious nature of the organism and the time it takes to grow. However, culture on Bordet-Gengou medium remains a gold standard for isolation.

## **Correct Answer:** B. Bordet-Gengou medium.