Beta-lactamase production is a mechanism of resistance common to strains of H. influenzae, M. catarrhalis, and Neisseria gonorrhoeae. Which one of the following drugs is most likely to be effective against ALL strains of the above organisms?
**Core Concept**
Beta-lactamase production is a mechanism of resistance in which bacteria produce enzymes that inactivate beta-lactam antibiotics, such as penicillins and cephalosporins. This resistance mechanism is common to several bacteria, including H. influenzae, M. catarrhalis, and Neisseria gonorrhoeae.
**Why the Correct Answer is Right**
A drug that is resistant to beta-lactamase degradation would be effective against all strains of these organisms. The drug Ceftriaxone is a third-generation cephalosporin that has a broad spectrum of activity and is stable against beta-lactamase degradation. It can penetrate into the cells of these bacteria and inhibit cell wall synthesis, leading to bacterial death. Ceftriaxone's stability against beta-lactamase enzymes makes it an effective choice against all strains of H. influenzae, M. catarrhalis, and Neisseria gonorrhoeae.
**Why Each Wrong Option is Incorrect**
**Option A:** Amoxicillin is a beta-lactam antibiotic that is commonly used to treat a variety of infections, but it is susceptible to beta-lactamase degradation and would not be effective against beta-lactamase-producing strains of these organisms.
**Option B:** Ciprofloxacin is a fluoroquinolone antibiotic that has a broad spectrum of activity, but it is not effective against beta-lactamase-producing strains of H. influenzae, M. catarrhalis, and Neisseria gonorrhoeae.
**Option D:** Erythromycin is a macrolide antibiotic that is effective against a variety of bacterial infections, but it is not effective against H. influenzae, M. catarrhalis, and Neisseria gonorrhoeae.
**Clinical Pearl / High-Yield Fact**
When treating infections caused by beta-lactamase-producing bacteria, it's essential to use antibiotics that are stable against beta-lactamase degradation, such as third-generation cephalosporins like Ceftriaxone.
**Correct Answer:** C. Ceftriaxone