FIG. 5.

Growth phase regulation of H. pylori vacA transcription. H. pylori 60190 VX-1 (containing a vacA::xylE transcriptional fusion) and H. pylori VX-1/LC-1 (containing both a vacA::xylE transcriptional fusion and a luxS::CAT mutation) were grown in brucella broth containing 5% FBS. Aliquots were removed at serial time points for measurement of XylE specific activity (A) and cell density (OD₆₀₀) (B). Levels of vacA transcription, as evidenced by XylE activities, were growth phase dependent, but this phenomenon was not dependent on LuxS function.