Read about it here: http://www.wired.com/wiredscience/2010/12/news-update-farm-animals-get-80-of-antibiotics-sold-in-us/
That's right, 80% of all antibiotics used aren't for when Johnny has strep, but go into the farm animals which eventually wind up on your plate.
This, as you can imagine, is not good. According to the Natural Resources Defense Council the scientific consensus is that non-therapeutic use of antibiotics in livestock animals is a serious threat to public health. Here's what the article had to say about it:
Most of the drugs used in animal agriculture and in human medicine are functionally identical. That’s one reason why the overuse of antibiotics in animals is such a concern: When organisms become resistant on the farm to drugs used on livestock, they are becoming resistant to the exact same drugs used in humans.
What's truly amazing is that the majority of these drugs aren't used because chickens, cows and pigs are sick, but to promote faster growth. In other words, it's all about making more money faster.
Of course, since we have a corporate-controlled food system, and a corporate-controlled government, nothing will be done about this.
The only thing you can do to reduce the threat to yourself and your family is to eat less meat and when you do eat it try to make sure it's hormone and anti-biotic free.