<i>RpoN</i> is involved in <i>H. pylori</i> 26695 survival during the stationary phase.

<p>(A) RT-PCR analysis of the mRNA levels of sigma factors in <i>H. pylori</i> 26695 at different growth stages. Data are mean ± SEM from 3 independent experiments. (B) The survival of <i>ΔrpoN</i> strain was deficient during the stationary phase. Bacteria were cultured in Brucella broth containing 10% fetal bovine serum, and numbers of colony formation units (CFU) per milliliter were determined at the times indicated. A representative assay of at least 3 trials is shown. Data are mean ± SEM from 3 independent experiments. (C) Lack of nutrition induces coccoid transformation and death of <i>H. pylori</i> cells. Wild-type and <i>ΔrpoN</i> mutant strain were cultured in liquid medium for 144 h. Cells stained with membrane-permeant SYTO 9 (green) and membrane-impermeant PI (red) were visualized by confocal microscopy. Data are representative of 3 independent experiments.