Final answer:
First-generation cephalosporins cover both gram-positive and some gram-negative bacteria.
Step-by-step explanation:
Cephalosporins are a group of antibiotics that inhibit bacterial cell wall synthesis, making them effective against certain bacteria. The first-generation cephalosporins have a narrow spectrum of activity and primarily cover gram-positive bacteria, similar to penicillin. However, they are also active against some gram-negative bacteria, providing them with a broader spectrum of activity compared to penicillin. Examples of bugs covered by first-generation cephalosporins include Staphylococcus aureus, Streptococcus pyogenes, Escherichia coli, and Klebsiella pneumoniae.