MRSA, or Methicillin-resistant Staphylococcus aureus (Pronounced Mursa) is a game played in City Charter High School, originated in Team B, in which the participants run up to one another, slap each other in the face, scream MRSA, and run away, thus leaving the slapee with MRSA. They then go and slap someone else, in an ongoing epidemic of MRSA.
"DOOD! Nate just ran up to me and slapped me! I GOT FUCKIN' MRSA!"