Key Findings

The study identifies and characterizes various OXA-48-like beta-lactamases, determining their ability to hydrolyze carbapenems and penicillins. A cutoff value of 0.27 mM−1·s−1 for the kcat/Km ratio of imipenem hydrolysis is proposed to distinguish carbapenemase-producing OXA-48 variants from non-carbapenemases.