 Methicillin-resistant Staphylococcus aureus, MRSA, is a dangerous pathogen that can cause severe infections even after receiving appropriate antibiotics. It is characterized by its ability to survive in the bloodstream for multiple days, which is often due to the host's immune system not being able to effectively fight off the infection. Factors such as the patient's age, underlying medical conditions, and the type of antibiotic administered all play a role in determining whether or not the infection will be persistent. Treatment options include surgery, antimicrobial therapy, and other measures such as hyperbaric oxygen therapy. Diagnosis of persistent MRSA bacteremia requires careful consideration of the patient's history, physical examination, and laboratory tests. This article was authored by Joshua B. Parsons and NetSea Westgeist, Brian P. Conlon, and others.