In vitro activity of the aminoglycoside antibiotic arbekacin against Acinetobacter baumannii-calcoaceticus isolated from war-wounded patients at Walter Reed Army Medical Center

We determined the in vitro MIC of arbekacin against 200 Acinetobacter isolates recovered from wounded soldiers. The median MIC was 2 μg/ml (range, 0.5 to >64 μg/ml). A total of 97.5% of the isolates had arbekacin MICs of <8 μg/ml and 86.5% had MICs of ≤4 μg/ml. There was no association between the arbekacin MIC and susceptibility to 16 other antibiotics or the specimen source (P = 0.7239). Synergy testing suggested an enhanced effect of arbekacin-carbapenem combinations.