Modern Acinetobacter baumannii clinical isolates replicate inside spacious vacuoles and egress from macrophages
Fig 5
UPAB1 escapes the macrophages by a lytic process.
J774A.1 macrophages were infected with UPAB1. (A) At different time points, antibiotic containing medium was replaced by antibiotic-free medium. CFU in supernatants were determined and the ratio of released to intracellular bacteria was calculated. Data represent mean and standard deviation values for 3 independent experiments. (B) Images from time-lapse microscopy showing UPAB1 egress from the invaded macrophages. J774A.1 cells were infected with UPAB1 GFP (green fluorescence). At 7 h p.i. images were taken every 10 min and analyzed with ImageJ software. The white arrow indicates the infected cell. Bars: 20 μm. (C) LDH activity in the supernatant of infected macrophages was measured at 24 h p.i. Percentage of cytotoxicity was calculated as the activity of released LDH relative to total LDH activity. The mean ± S.D. for two independent experiments is shown. **** p < 0.0001.