FIG 3.
Intracellular activity of rifabutin (RFB) alone, in combination with imipenem (IPM), or in combination with imipenem (IPM) and avibactam (AVI). (a) Rifabutin (16 μg/ml) alone or in combination with imipenem (8 μg/ml and 32 μg/ml) against M. abscessus CIP104536 and its ΔblaMAb derivative. (b) Rifabutin (1 and 8 μg/ml) alone, in combination with imipenem (8 μg/ml), or in combination with imipenem (8 μg/ml) and avibactam (16 μg/ml) against M. abscessus CIP104536. Intracellular bacteria were enumerated, and the fold change in CFU counts was determined between days 0 and 2 postinfection. Values are means of three independent experiments. Bars represent standard deviations. A Mann-Whitney U test was used to compare M. abscessus CIP104536 and its ΔblaMAb derivative.