noun
meningococcus; Neisseria meningitidis
Medical term for the bacterium that causes meningococcal meningitis.
髄膜炎菌は、髄膜炎の主な原因菌の一つです。
Meningococcus is one of the main causative bacteria of meningitis.
髄膜炎 is the disease (meningitis), while 髄膜炎菌 is the bacterium that causes it.
Compound of 髄膜 (meninges) + 炎 (inflammation) + 菌 (bacterium), literally 'meningitis bacterium'.