After completing this article, readers should be able to:

Cephalosporins are beta-lactam antimicrobials that share mechanisms of action and a similar structure with penicillins (FigureF1). Penicillins and cephalosporins have the same four-member “core” beta-lactam ring, but cephalosporins have an additional atom in the side ring. Modified side chains on either ring alter antimicrobial activity, resistance to beta-lactamases, or pharmacokinetics. Penicillin-susceptible pathogens usually are cephalosporin-susceptible. Exceptions are Listeria and Pasteurella sp. Cephalosporins have activity against common gram-negative organisms such as Escherichia coli, nontypeable Haemophilus influenzae (ntHi), and methicillin-susceptible Staphylococcus aureus (MSSA), but all methicillin-resistant S aureus (MRSA) and enterococci are cephalosporin-resistant. Because of minimal use or current unavailability, we will not discuss cephalothin, moxalactam, cefamandole, cefonicid, ceforanide, ceftizoxime, cefoperazone, cefpirome, cefmetazole, or cefotetan.

To help understand the mechanism of action of cephalosporins, rigid bacterial cell walls can be considered as a series of repeating interlocking units reminiscent of...

You do not currently have access to this content.