They have to culture MRSA and see what antibiotic will kill it because it it so resistant. I hope your doctor has done that instead of just prescribing an antibiotic that he thinks will work. Sometimes the antibiotics will stave off the infection for a while but unless it's been cultured and proven to kill the MRSA you'll keep fighting outbreaks.
My daughter had it and ended up going to a dermatologist who knew what he was doing.
Trinity
What kind of doctor has been treating you for your infections all summer? It seems to me that a case of MRSA would call for the best antibiotic treatment they can come up with, especially if it is in your lungs. I don't know if a GI will treat it because GI stands for gastro-intestinal, and none of your infections are in that part of the body. You may need an infectious disease doctor.
Diane