Culture of Lepra bacillus is done on –
**Core Concept**
The culture of Lepra bacillus, also known as Mycobacterium leprae, is a complex process due to its unique characteristics and fastidious growth requirements. M. leprae is an obligate intracellular pathogen that cannot be cultured on artificial media.
**Why the Correct Answer is Right**
The correct answer is **A. Footpad of mouse**, as M. leprae is grown in the footpad of mice, which is the only suitable host for its cultivation. The bacteria multiply within the Schwann cells of the peripheral nerves, causing nerve damage and leading to the characteristic symptoms of leprosy. The footpad of mice provides a suitable environment for the growth of M. leprae, allowing for the study of its pathogenesis and the development of new treatments.
**Why Each Wrong Option is Incorrect**
* **Option B:** Egg yolk medium is used for the cultivation of other mycobacteria, such as M. tuberculosis, but not M. leprae.
* **Option C:** Blood agar is a general-purpose medium used for the cultivation of a wide range of bacteria, but it is not suitable for M. leprae.
* **Option D:** Synthetic media, such as Löwenstein-Jensen medium, are used for the cultivation of M. tuberculosis and other fastidious bacteria, but they are not suitable for M. leprae.
**Clinical Pearl / High-Yield Fact**
M. leprae is a unique pathogen that cannot be cultured on artificial media, making it difficult to study and treat. The use of mouse footpads as a culture medium has been instrumental in the development of new treatments and our understanding of the pathogenesis of leprosy.
**Correct Answer:** A. Footpad of mouse.