MRSA Wall Lattice: PBP2a Antibiotic Evasion Simulator (2D)

Beta-lactam antibiotics work by binding penicillin-binding proteins (PBPs), the transpeptidase enzymes that crosslink a bacterium's peptidoglycan wall. This simulator unrolls that wall into its canonical 2D lattice — horizontal glycan strands linked by vertical peptide crosslinks — then lets you dose it with a beta-lactam and dial in how much of the population's transpeptidase activity runs through PBP2a, the low-affinity enzyme encoded by the mecA gene that makes MRSA resistant. Pan and zoom the mesh to watch individual crosslink sites flip between intact and inhibited, and read wall integrity and crosslink density live on the strip chart: at low PBP2a expression the wall collapses and the cell lyses once antibiotic concentration passes the MIC, while high PBP2a expression keeps the wall intact even at ten times that dose — exactly reproducing why methicillin-class drugs fail against MRSA.