Which of the following is NOT a class of beta-lactam antibiotics?

• A. Monobactams
• B. Aminoglycosides
• C. Carbapenems
• D. Cephalosporins

Answer: (B)

Beta-lactam antibiotics are characterized by their shared structure that includes a beta-lactam ring, which is crucial for their antibacterial activity. The classes of antibiotics that fall under this category include monobactams, carbapenems, and cephalosporins, all of which contain this distinctive ring structure that allows them to inhibit bacterial cell wall synthesis.

Monobactams, such as aztreonam, are a class of beta-lactam antibiotics that are effective primarily against Gram-negative bacteria. Carbapenems, which include agents like meropenem and imipenem, have a broad spectrum of activity against both Gram-negative and Gram-positive bacteria. Cephalosporins are another class of beta-lactams that offer a wide range of activity and are classified into generations based on their spectrum of activity and resistance to bacterial enzymes.

In contrast, aminoglycosides, such as gentamicin and amikacin, do not belong to the beta-lactam family. Instead, they work by inhibiting protein synthesis in bacteria and have a different mechanism of action that fundamentally distinguishes them from beta-lactam antibiotics. This difference in structure and mechanism is why aminoglycosides are correctly identified as not being a class of beta