MecA_Resistance.svg (1)

Diagram depicting antibiotic resistance through alteration of the antibiotic’s target site, modeled after MRSA’s resistance to penicillin. Beta-lactam antibiotics permanently inactivate PBP enzymes, which are essential for bacterial life, by permanently binding to their active sites. MRSA, however, expresses a PBP that will not allow the antibiotic into its active site. (Photo credit: Wikipedia)