Hello!! Thank for giving me and JA a chance to help you out!
MRSA is a resistant form of a bacteria called staphlococcus aereous. This bacteria is common on the outer skin of everyone. This particular strain of this bacteria is not killed by some of the antibiotics - thus calling it resistant. When you get an infection of MRSA as with any other infection there is swelling, redness, drainage and warmth of the area. So in a nut shell - swelling of the infected area would not be unusual.