“…Genome sequencing of two CA-MRSA strains, the Midwest Clone MW2 (USA400) and the pandemic clone USA300 [7,[9][10][11]25,26], revealed that ~20% of the unique genomic contents of CA-MRSA strains are due to the horizontal acquisition of multiple mobile genetic elements, including prophages and pathogenicity islands, which are absent from the traditional hospitalassociated MRSA strains COL, N315 and MRSA252 ( Figure 2). The prophages and pathogenicity islands contained numerous specialized pathogenicity factors, such as enterotoxins and exoproteins that could allow CA-MRSA to evade or subvert host defenses [25,26].…”