We report the use of tigecycline, firstly with colistin and finally alone, in a patient with a persistent breakthrough bacteremia due to a Klebsiella pneumoniae isolate harboring a metallo-beta-lactamase (VIM-1) and an extended-spectrum beta-lactamase (SHV-12). Time-kill studies demonstrated that the combination of both compounds was synergistic along the first 12 h, suppressing the regrowth observed after 3 to 6 h when colistin was tested alone.