Which generation of cephalosporins are most effective against gram-positive cocci?

The first generation of cephalosporins is most effective against gram-positive cocci due to their structure and mechanism of action. These antibiotics, such as cefazolin and cephalexin, have a high affinity for penicillin-binding proteins found in the cell walls of gram-positive bacteria. This allows them to effectively inhibit bacterial cell wall synthesis, leading to cell lysis and death of the organisms.

First generation cephalosporins were specifically designed to target and combat infections caused by streptococci and staphylococci, which are common types of gram-positive cocci. As the generations progress, cephalosporins have increasingly targeted gram-negative organisms, making them less effective at treating infections caused by gram-positive bacteria. Therefore, the first generation stands out for its potency against those specific pathogens.