Which regimen is effective against CRE (carbapenem-resistant Enterobacterales) due to inhibition of beta-lactamases?

Which regimen is effective against CRE (carbapenem-resistant Enterobacterales) due to inhibition of beta-lactamases?

• A. Ceftazidime-avibactam
• B. Amoxicillin-clavulanate
• C. Meropenem
• D. Cefuroxime

Answer: (A)

Beta-lactamase inhibitors can restore the activity of beta-lactams when resistance is driven by enzyme production. Ceftazidime paired with avibactam works well against many carbapenem-resistant Enterobacterales because avibactam blocks a broad range of carbapenemases (notably class A enzymes like KPC and some class D OXA-48–like enzymes), preventing the enzyme from destroying the cephalosporin. This reactivates the antibiotic against CRE strains where beta-lactamase production is the main resistance mechanism. In contrast, amoxicillin-clavulanate has limited effectiveness against carbapenemases and isn’t reliably active against CRE; meropenem is a carbapenem itself and CRE have enzymes that inactivate it; cefuroxime is a cephalosporin without sufficient inhibition to overcome the carbapenemases. It’s also worth noting that some CRE carry metallo-beta-lactamases, which avibactam does not inhibit, requiring alternative strategies.

Beta-lactamase inhibitors can restore the activity of beta-lactams when resistance is driven by enzyme production. Ceftazidime paired with avibactam works well against many carbapenem-resistant Enterobacterales because avibactam blocks a broad range of carbapenemases (notably class A enzymes like KPC and some class D OXA-48–like enzymes), preventing the enzyme from destroying the cephalosporin. This reactivates the antibiotic against CRE strains where beta-lactamase production is the main resistance mechanism. In contrast, amoxicillin-clavulanate has limited effectiveness against carbapenemases and isn’t reliably active against CRE; meropenem is a carbapenem itself and CRE have enzymes that inactivate it; cefuroxime is a cephalosporin without sufficient inhibition to overcome the carbapenemases. It’s also worth noting that some CRE carry metallo-beta-lactamases, which avibactam does not inhibit, requiring alternative strategies.