Comment Re:Do we know the geographical source? (Score 1) 28
It's not even that. Most of the drug-resistant bacteria existed before antibiotics came out of the lab. But they weren't a very successful part of the population. Antibiotics killed off their competition, and now they're successful. Most methods of resisting antibiotics have an energy cost, so bacteria that don't use them are more successful if the antibiotics aren't around. Unfortunately, it's not usually a very high cost, so stopping the use of an antibiotic doesn't reset the population, at least not quickly.
But, yeah, bacteria mutate really rapidly to fill a new niche, so you probably literally CAN'T have an antibiotic both in wide use and remaining effective.