Evolution of Staph Superbug Traced Between Humans and Livestock.
After transferring to livestock, MRSA CC398 became resistant to two important antibiotics, tetracycline and methicillin, which are used for treating staph infections. The resistance likely is a result of the routine antibiotic use that characterizes modern food-animal production. The animals commonly are given antibiotics to prevent infection and promote growth. Keim, who also serves as director of TGen’s Pathogenic Genomics Division, said the study describes evolution in action. "The most powerful force in evolution is selection. And in this case, humans have supplied a strong force through the excessive use of antibiotic drugs in farm animal production. It is that inappropriate use of antibiotics that is now coming back to haunt us.”
