Question

Ceftriaxone is a β-lactam antibiotic and is primarily bactericidal. This means that:

1) azithromycin kills bacterial cells while ceftriaxone inhibits the growth of bacterial cells.
2) bacteria are sensitive to azithromycin but are resistant to ceftriaxone.
3) azithromycin inhibits the growth of bacterial cells while ceftriaxone kills bacterial cells.
4) bacteria are resistant to azithromycin but are susceptible to ceftriaxone.
5) azithromycin can only be used against Gram-positive bacteria.

Answer 1

Azithromycin is a bacteriostatic antibiotic that inhibits protein synthesis, while ceftriaxone is a bactericidal antibiotic that disrupts cell walls, causing cell death. The correct match from the provided options is that azithromycin inhibits growth and ceftriaxone kills cells.

Step-by-step explanation:

The correct answer is: 3) azithromycin inhibits the growth of bacterial cells while ceftriaxone kills bacterial cells.

Ceftriaxone is a β-lactam antibiotic that interferes with the synthesis of the bacterial cell wall peptidoglycan layer, which leads to cell lysis and death, thus it is bactericidal. On the other hand, Azithromycin is a macrolide antibiotic that binds to the 50S subunit of the bacterial ribosome, thereby inhibiting protein synthesis, making it bacteriostatic under most circumstances.

This distinction is essential for understanding the mechanisms by which these antibiotics affect bacteria and their impact on different types of infections. Notably, Mycoplasma pneumoniae is resistant to drugs like amoxicillin that target cell wall synthesis because it lacks a cell wall, thus azithromycin's target on the ribosome makes it effective against such atypical bacteria. Also, the increasing resistance of Neisseria gonorrhoeae to various antibiotics, including azithromycin and ceftriaxone, is a significant concern in public health.