Medary.com

From White Coat Underground, apparently a doctors' blog:

In the mid 20th century, when antibiotics were invented, strains of Staph resistant to penicillins rapidly evolved.

Time for an aside: “Evolved”, as in “evolution”. I know that very few of my readers are likely to be creationists, but this is one of the reasons creationism/intelligent design is so dangerous. Knowledge of evolutionary biology allows the prediction of antibiotic resistance. Creationism does not–its teleological arguments simply posit that God created resistant bacteria because He knew ahead of time about penicillin (or some such nonsense). ID has no predictive value, and is therefore worthless. End of digression.

Emphasis mine.