Additional studies are in progress to assess the susceptibility of the penicillinase activity observed in these strains to beta-lactamase inhibitors.

Beta-lactamase inhibitors such as clavulanate, sulbactam, and tazobactam in vitro inhibit most ESBLs, but the clinical effectiveness of beta-lactam/beta-lactamase inhibitor combinations cannot be relied on consistently for therapy.

Although beta-lactamase inhibitors have little antibiotic activity of their own, they instead inhibit the activity of beta-lactamases, a family of enzymes that break the beta-lactam ring that allows penicillin-like antibiotics to work, thereby conferring bacterial resistance.