Interactions between Avibactam and Ceftazidime-Hydrolyzing Class D β-Lactamases

Abstract

Class D β-lactamases exhibit very heterogeneous hydrolysis activity spectra against the various types of clinically useful β-lactams. Similarly, and according to the available data, their sensitivities to inactivation by avibactam can vary by a factor of more than 100. In this paper, we performed a detailed kinetic study of the interactions between two ceftazidime-hydrolyzing OXA enzymes and showed that they were significantly more susceptible to avibactam than several other class D enzymes that do not hydrolyze ceftazidime. From a clinical point of view, this result is rather interesting if one considers that avibactam is often administered in combination with ceftazidime.

Keywords

• class d β-lactamases
• oxa-β-lactamases
• oxa-24
• oxa-163
• oxa-427
• avibactam
• ceftazidime