Just about anyone who works in a hospital is colonized with MRSA (Methicillin resistant Staphylococcus aureus), as is half the community really. Staph aureus is found in our nares, on our skin, in our ears, our pores... more places than one would think. It is a never ending cycle... infection, hospitalization, colonization, introduction to the community. Unfortunately, we have no one but ourselves to blame for it. In a society that is so free with antibiotics, our natural flora (which does include Staph aureus) has overstepped the boundaries of our previous pleasant symbiotic relationship to protect itself against the onslaught of antibiotics, bacteriostatic and antibacterial solutions, and antimicrobial mixes that are found just about everywhere. While as a nurse, I can definitely appreciate cleanliness (and thankfully since I do work in surgery), but there are certain lengths we shouldn't have gone to.
Now that I'm done with that rant (and as a micro nerd, it is indeed a rant - its a sore spot for me), MRSA is indeed treatable. It can sometimes take a long time with many different types of antibiotics that can sometimes invite a slew of side effects, but it is definitely treatable. Usually, Vancomycin is given since it has proven to be the most effective against MRSA. It is a very powerful antibiotic that can sometimes cause more problems that it can treat. I would discuss antibiotic treatments with your Doctor to see what your options are. Antibiotics kill ALL bacteria they come in contact with, including our good bodily bacteria. As was stated above, a very common side effect to intense antibiotic treatment is an overgrowth of the hardy bowel bacterium C.diff (Clostridium difficile), which trust me you want absolutely NO part of!
Make sure to keep the wound area clean and covered at all times. While the body's normal defenses are usually enough to combat bacteria defense - even the feared MRSA - a weakened immune system is like an invitation. In order to keep the infection from happening again, you will want to keep as much of the bacteria isolated. Try to stay in unless necessary, clean and bandage the wound in one particular spot in the home... a spot you can easily disinfect. Most importantly, wash your hands. If you think you've washed them enough, wash them 10 more times. Good hand hygiene is a life saver. A MRSA in infection is not the end of the world, but definitely needs to be treated with respect.
Being anemic probably prevented your bloodstream from carrying enough leukocytes to the site of infection, though I am no hematologist. My guess... MRSA was introduced to the open wound via outside influences, or you could be colonized (which is more likely a case). Generally, MRSA does not decide to spout from the body like Athena from Zeus. There is usually a point of entry (cut, wound, abrasion, etc) which provides the perfect environment for the bacteria to thrive in and then enters and infects the tissue, and eventually the blood stream.