The MRSA or the Methicillin-resistant Staphylococcus aureus strain is among the dangerous strains of Staphylococcus aureus. This strain can cause infections which may prove to be severe. The antibiotic-resistance of this strain makes it harder to treat it. Although most of the infections caused by this strain of bacteria are not much dangerous, but a few can be life-threatening. It is also known as the 'superbug'. Hence, the doctor was concerned to find MRSA strains in George's wound.