The human body fights staph infections by starving it of essential nutrients. Staph, it turns out, is remarkably good at changing what's on the menu. Staphylococcus aureus—the infamous agent behind MRSA and most staph infections—needs sulfur to build proteins and other materials essential for survival. In a new Michigan State University study, published in the Journal of Bacteriology, researchers found the bacterium can adjust its diet depending on what sources remain available.