In vitro activity of the siderophore monosulfactam BAL30072 against meropenem-non-susceptible Acinetobacter baumannii.

Objective: The activity of BAL30072 was compared with that of anti-Acinetobacter reference drugs against meropenem-non-susceptible Acinetobacter baumannii isolates associated with up-regulation of the intrinsic OXA-51-like enzyme or an acquired OXA.

Methods: Antimicrobial susceptibility testing was investigated by broth microdilution of 310 non-duplicate, meropenem-non-susceptible A. baumannii isolates to BAL30072, amikacin ampicillin/sulbactam, aztreonam, cefepime, colistin, imipenem, levofloxacin, meropenem, rifampicin, tigecycline and tobramycin.

Results: BAL30072 showed greater activity than the β-lactam comparators, levofloxacin, amikacin, tobramycin and rifampicin. The activity of BAL30072 was comparable to that of tigecycline, with an MIC(50) of 2 mg/L. Elevated BAL30072 MICs were found, but there was no correlation with elevated MICs of the other antimicrobials.

Conclusions: BAL30072 is a promising new agent with good activity against carbapenem-non-susceptible A. baumannii.