Infections with certain bacteria,including streptococci (e.g., cause scarlet fever, sore throats and tonsillitis in humans), and staphylococci (e.g., cause boils, meningitis and septicaemia). It was by means of a contaminated culture plate of staphylococci that Alexander Fleming (1861-1955) discovered penicillin for which he shared the Nobel Prize for Physiology or Medicine in 1945.
See Meningitis