A nurse is preparing to administer ceftriaxone (Rocephin) to a client who has bacterial meningitis.
The nurse should recognize that this medication is effective against which type of bacteria?
A.
Gram-positive
B.
Gram-negative
C.
Anaerobic
D.
Aerobic.
The Correct Answer and Explanation is:
The correct answer is B. Gram-negative.
Explanation:
Ceftriaxone (Rocephin) is a broad-spectrum cephalosporin antibiotic that is commonly used in the treatment of various bacterial infections, including bacterial meningitis. This drug is particularly effective against Gram-negative bacteria, which are characterized by their cell wall structure and staining properties in laboratory tests.
Gram-negative bacteria have a unique cell wall structure that includes an outer membrane containing lipopolysaccharides. This outer membrane acts as a barrier to many antibiotics, but ceftriaxone can penetrate this barrier due to its broad-spectrum nature. Ceftriaxone’s effectiveness against Gram-negative bacteria stems from its ability to inhibit bacterial cell wall synthesis by binding to penicillin-binding proteins (PBPs) in these organisms. This action ultimately leads to cell lysis and death.
Ceftriaxone is less effective against Gram-positive bacteria compared to Gram-negative ones. While it does have some activity against Gram-positive bacteria, it is generally not the first choice for infections primarily caused by Gram-positive organisms. The efficacy of ceftriaxone against Gram-positive bacteria is more variable and may be less robust than its activity against Gram-negative bacteria.
The antibiotic also has limited activity against anaerobic bacteria, which do not require oxygen for growth and are often found in different types of infections compared to aerobic bacteria. Anaerobes often require specific antibiotics such as metronidazole or clindamycin for effective treatment.
Aerobic bacteria can thrive in the presence of oxygen, and while ceftriaxone is effective against many aerobic Gram-negative bacteria, the term “aerobic” is not as specific as “Gram-negative” in describing the primary spectrum of activity of ceftriaxone.
In summary, ceftriaxone is most notably effective against Gram-negative bacteria, making it a suitable choice for treating infections caused by these pathogens, including certain cases of bacterial meningitis.