Lab Medicine Significance 6/10

Susceptibility Testing for New Beta-Lactam/Beta-Lactamase Inhibitor Combinations: A Laboratory Guide

Ceftazidime-avibactam, meropenem-vaborbactam, and imipenem-relebactam offer broad Gram-negative activity including against certain carbapenemases, but variable effectiveness against oxacillinases and acquired resistance mechanisms necessitates susceptibility testing. This review provides practical guidance for clinical laboratories on implementing and reporting AST for these critical new antimicrobial combinations.

The original study

The Ins and Outs of Susceptibility Testing for New β-Lactam/β-Lactamase Inhibitor Combinations for Gram-Negative Organisms.

Authors
Dingle TC, Pitout J
Journal
Journal of clinical microbiology
Type
Journal Article, Review
PMID
35387484
Read the original study →

Original abstract

Ceftazidime-avibactam, meropenem-vaborbactam, and imipenem-relebactam are among the newest β-lactam/β-lactamase inhibitors (BL/BLIs) introduced to the North American antibiotic market. All have broad Gram-negative activity, including against certain carbapenemases. Despite this, susceptibility testing is warranted due to variable activity against certain β-lactamases (e.g., oxacillinases) and the presence of acquired resistance mechanisms in some isolates. Here, we discuss what we know about these new antimicrobial agents and how to navigate implementation of susceptibility testing and reporting of these agents in clinical laboratories.