Don’t pick your nose
Hugh Pennington: Staphylococcus aureus, 15 December 2005
“... in London were penicillin-resistant. By early 1947 the percentage had tripled. The bacteriologist Mary Barber showed that this rise was not due to the development of resistance while patients were being treated, but to the spread of a penicillin-resistant strain in the hospital. Some staphylococci had the ability to make penicillinase, a penicillin-destroying ... ”