Citing a recent meat recall, the second-largest in the nation's history, cardiologist Dr. Jeff Ritterman of California, USA speaks out in August 2011 against excessive use of antibiotics in factory farming, saying that it is promoting the rapid increase of multiple antibiotic-resistant bacteria and could even be linked to methicillin-resistant Staphylococcus aureus (MRSA), which claims more lives each year than AIDS.

http://www.huffingtonpost.com/2011/08/16/factory-farms-antibiotic-resistance-doctors_n_928140.html
http://greenanswers.com/news/257202/doctors-speak-out-against-livestock-antibiotics