The problem is it is not just the antibiotics used in producing food. There was a time when people would run to the doctor for every little thing to get an antbiotic when they really didn't need them but the doctor would give them any way. In fact I'm sure it is still happening. So of course all the bacteria started building up reistance.
Worse than doctors pescribing not needed drugs to make patients happy there are lots of people that are too stupid (IMO) to understand what they read. I've know people who said that they would take the antibiotics until they felt better and save the rest for the next time they were sick. Or with their kids if one was sick and was prescribe an antibiotic they would give it until the kid was "well" and if one of the other kids got sick they would use the rest for that kid.
Hey people it says right on the bottles TAKE ALL OF THE PRESCRIPTION. The reason is if you don't then the bacteria doesn't get completely killed and eventually you get sick again only now it has probably mutated right your own prviate bacteria factory -- your own body. So even though I don't think that they should use so much of it in food production I think the biggest problem comes from peoples improper use of the drugs on themselves.
