Antibacterial activity of SQ109 against slow-growing <i>H. pylori</i> and synergy with chloramphenicol, Cm.

<p>A predetermined bacteriostatic concentration of Cm (30 µM), was used to induce slow growth. Synergistic effects of SQ109 and Cm was then examined using two approaches: <b>A</b>) <i>H. pylori</i> strain G27 liquid cell cultures were treated simultaneously with 30 µM Cm and SQ109 (0 µM, 140 µM, and 200 µM) (open symbols), and the cells were monitored for 24 h, and <b>B</b>) <i>H. pylori</i> strain G27 cells were initially incubated with 30 µM Cm for 16 h in liquid culture medium before being split into multiple samples for further incubation with varying concentrations of SQ109 (0 µM, 10 µM, 70 µM or 140 µM) (open symbols) plus Cm. In both approaches, bacterial cells incubated with only PBS, SQ109 (0 µM, 10 µM, 70 µM, 140 µM or 200 µM) or Cm alone, were used as controls (closed symbols). The data are representative results from three independent experiments. The horizontal dashed line on each graph indicates the limit of detection (500 bacteria).