These researchers found 149 different genes encoding antibiotic resistance, some of which were present at levels 192 to 28,000 times higher than control samples.
The Time article goes on to frame the problem of antibiotic use in the animal industry:
1) In the United States, 4 times the amount of antibiotics that are used in humans are used for animals, many to treat otherwise healthy animals to promote growth
2) It is not clear to what extent this occurs (using antibiotics to promote animal growth-not expressly to treat sick animals)
3) Antibiotic resistance that develops in animals is a problem for humans-resistance genes can be carried in fertilizer, washed into rivers, et cetera. I previously touched on this in a blog about contaminated pork products and in another blog post about antibiotic use in cattle.
See here for a link to an excellent perspective article on why antibiotic resistance matters, and what can be done to prevent entering a "post-antibiotic era." It has been well under 100 years since antibiotics were discovered and went into widespread use, and already we are seeing infections emerge that are completely resistant to all of the antibiotics in our arsenal. To a large extent this is due to the selective pressure of antibiotics on microorganisms.
In order to secure a future in which we still have antibiotics to treat infections, we need to decrease antibiotic selective pressure on microorganisms wherever appropriate. This includes utilizing antibiotics judiciously in the animal growth industry; as mentioned in the Time article, we don't even know the scope of the problem. It is clear that we must act decisively, and concertedly, to address the problem of antibiotic resistance.