This, I must say is a complete detailed article on Antibiotic Resistance.
It brought some memories of what I was thought in Pharmaceutical classes in my undergraduate days.

It might be surprising to you to learn that resistance to antibiotics was identified even before Fleming's drug hit the shelves. The first clinical application of penicillin came in the early 1940s, but the discovery of beta-lactamase (a bacterial enzyme capable of destroying penicillin) preceded that revolution by a few years. The microbes were always one step ahead.

But this one knowledge got me... I never thought these precious organisms already had a defensive plan on ground before we could even discover the weapon penicillin... always one step ahead indeed!