Impact of β-Lactamase Inhibition on the Activity of Ceftaroline against Mycobacterium tuberculosis and Mycobacterium abscessus.

The production of beta-lactamases BlaMab and BlaC contributes to beta-lactam resistance in Mycobacterium abscessus and Mycobacterium tuberculosis, respectively. Ceftaroline was efficiently hydrolyzed by these enzymes. Inhibition of M. tuberculosis BlaC by clavulanate decreased the ceftaroline MIC from >= 256 to 16 to 64 mu g/ml, but these values are clinically irrelevant. In contrast, the ceftaroline-avibactam combination should be evaluated against M. abscessus since it inhibited growth at lower and potentially achievable drug concentrations.