noun
Mycobacterium leprae; leprosy bacillus
Scientific/medical term for the bacterium that causes leprosy (Hansen's disease).
らい菌は、1873年にアルマウェル・ハンセンによって発見された。
Mycobacterium leprae was discovered by Armauer Hansen in 1873.
Hansen's disease (leprosy) is the modern, non-stigmatizing term for the illness caused by らい菌. らい菌 refers specifically to the bacterium.
Compound of らい (leprosy, from Middle Chinese 癩) and 菌 (bacterium, from Middle Chinese 菌).