Antibiotics

First-generation cephalosporin

β-lactam — inhibits bacterial cell wall PBPs.

Glycopeptide antibiotic

Inhibits cell wall synthesis (binds D-Ala-D-Ala). Active against MRSA + gram-positives.

Lincosamide protein-synthesis inhibitor

Binds 50S ribosomal subunit, blocks peptide-bond formation. Bacteriostatic against most organisms; bactericidal against susceptible streptococci. Excellent activity against anaerobes and gram-positive cocci including community-acquired MRSA.

Aminoglycoside protein-synthesis inhibitor

Binds 30S ribosomal subunit, causes misreading of mRNA → defective bacterial protein synthesis. Bactericidal, concentration-dependent killing. Synergy with cell-wall agents (β-lactams, vancomycin) for gram-positive endocarditis.