This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Bacteria, Subject name: Microbiology
Culture of Lepra bacillus is done on - 
Select and explain. 
A. L J medium, B. Robertson's cooked meat medium, C. Foot pad of mice, D. Sabraud's agar
C: Foot pad of mice
Answer: C: Foot pad of mice 
Explanation: Ans. is 'c' i.e., Foot pad of mice * M. leprae is obligate intracellular organism, thus cannot be grown in cell free culture medium. Two animals are used for cultivation1. Armadillo (Nine banded armadillo) is highly susceptible and provides sufficient bacilli for a number of studies and for production of skin test reagent, Lepromin A.2. Foot pad of mice has been used for testing of sensitivity of antileprotic drug (replication in foot pad of mice is limited and less numerous than armadillo).* Generation time of M. leprae is 12-13 days.