How Are Wounds Caused By MRSA Treated?

I had a deep wound appear, seeping puss &/or blood. I was at my PCP today & he looked at it & said MRSA. I started sulfamethoxazole - trime 800-160 tabs yet it says to take 2X/day for 10 days, and indeed, had 20 in the bottle. I'm to see the dr in 3 wk, but that could be bc his ofc is closed from the day b4 Thanksgiving to several days into the following week. He said to keep it covered by gauze w no dressing. Is this how you'd treat it? & he did not take any test whatsoever. It's a large crease that's opened where I had an incision yrs ago for endometriosis op (3rd op for it was that one when I had hysterectomy).