Which antibiotic class is NOT effective against anaerobes?

Monobactams are a class of antibiotics that typically target aerobic Gram-negative bacteria, particularly those exhibiting resistance to other classes of antibiotics. They have a specific action profile and are not effective against anaerobic bacteria.

In contrast, other classes of antibiotics, such as cephalosporins, carbapenems, and tetracyclines, have broader coverage that includes some anaerobic organisms. For example, certain cephalosporins can be effective against anaerobes, particularly those that are related to skin and soft tissue infections. Likewise, carbapenems cover a wide range of bacteria, including many anaerobic species, making them useful in treating polymicrobial infections. Tetracyclines also possess activity against various anaerobes, making them applicable in treating infections related to Bacteroides and other anaerobic organisms.

This specificity of monobactams in targeting primarily aerobic Gram-negative bacteria helps to differentiate them from other antibiotic classes that possess activity against anaerobic pathogens.