Chapter 28.10, Problem 1CR

Antibiotics are chemically diverse antimicrobial compounds produced by microorganisms. Each antibiotic works by inhibiting a specific cellular process in the target microorganisms. The β-lactam antibiotics, including penicillins and cephalosporins, target bacterial cell wall synthesis and are the most important class of clinical antibiotics. The aminoglycosides, macrolides, and tetracycline antibiotics selectively interfere with protein synthesis in Bacteria. The quinolones are an important class of synthetic antibacterial drugs that inhibit DNA synthesis. Daptomycin and platensimycin are structurally novel antibiotics that target cytoplasmic membrane functions and lipid biosynthesis, respectively.

What are the common sources for natural antibiotics? How do these antimicrobial drugs differ from growth factor analogs, such as the sulfa drugs? Why are β-lactam antibiotics generally more effective against gram-positive bacteria than against gram-negative bacteria?