Ga-PPIX time-kill assays. Ga-PPIX time-kill kinetics for A. baumannii ATCC 19606T (A) and ACICU (B) was determined after 0, 2, 4, 6, and 24 h of incubation by CFU count after exposure to 0 μg/ml (0× MIC), 10 μg/ml (0.5× MIC), 20 μg/ml (1× MIC), or 40 μg/ml (2× MIC) Ga-PPIX.