Resistances do die out; they typically aren't free to acquire. However, I suppose it's likely that a mere 30 years isn't enough to extinguish all traces, espec

Resistances do die out; they typically aren't free to acquire. However, I suppose it's likely that a mere 30 years isn't enough to extinguish all traces, especially since it's impossible to really mandate a world-wide ban on certain antibiotics. So even if resistance is reduced, it's possible it'll to come back quickly.