Pretty well covered above but summarizing:
1) Clean mats. Volunteer to do it yourself and see if the gym will knock off a few bucks from your dues or toss in a private session.
2) Shower immediately after getting home.
3) Wash your training clothes every night.
4) Keep the guy with MRSA off the friggin' mat!
1) Wash your hands before leaving the gym or use an anti-baterial wipe/Purell
2) Wipe off exposed skin (i.e. legs) with an anitbaterial/alcohol/baby wipe before leaving
And finish the complete cycle of whatever meds you are given.