MRSA stands for methicillin resistant Staphylococcus aureus (SA).  SA is a type of bacteria that is normally carried on the skin in about 30% of healthy individuals and usually does not cause problems unless there is some damage to the skin.    SA infections were typically able to be treated with penicillin-type of antibiotics, such as methicillin, but more recently there has been an increase in the number of infections by SA that are resistant to these antibiotics, termed MRSA.  Originally this bacterium tended to be confined to hospitals, but there has been recent concern that MRSA is now being seen much more commonly in the community.