A family of gram-negative bacteria of which three varieties cause disease. Neisseria meningitidis (‘meningococcus’) causes meningococcal meningitis and septicaemia. Neisseria gonorrhoeae causes gonorrhoea. Moraxella catarrhalis occurs in the nose and throat and sometimes causes ear infections.
A family of bacteria that are spherical, gram-negative, and nonmotile.