Which statement about cultivation and laboratory propagation of Mycobacterium leprae is correct?
- A It can be cultured on Lowenstein-Jensen medium within 8 weeks at 37 degrees Celsius
- B It multiplies in the footpads of mice and in the nine-banded armadillo, but cannot be grown in conventional artificial media ✓
- C It grows readily in cell culture monolayers, making serological diagnosis unnecessary
- D It replicates optimally at core body temperature, explaining its predilection for visceral organs
Correct answer: B. It multiplies in the footpads of mice and in the nine-banded armadillo, but cannot be grown in conventional artificial media
Explanation
M. leprae has never been reliably cultured on routine artificial media. Shepard's mouse footpad model and the nine-banded armadillo are the standard means of propagation and research. The organism prefers temperatures slightly below core body temperature, around 30 to 35 degrees Celsius, which explains its tropism for cool superficial sites such as skin, superficial peripheral nerves, nasal mucosa, anterior chamber of the eye, and testes. This thermal preference kills option D.
Reference: Harrison's Principles of Internal Medicine, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.