Fig. 1.

pH influences H. pylori speed and reversal frequency. (a) Low pH increases VCL in a chemotaxis-independent manner. (b) pH affects TL% to a modest extent. (c) pH has a significant influence on reversal frequency. All behaviour was measured in BB10 supplemented to the final concentration of HCl indicated. Each measurement is shown as mean±sem. (a, b) Each measurement derives from five bacteria that were tracked from three to four independently grown cultures. (c) Each measurement derives from at least 20 bacteria from at least two independently grown cultures, and is given as the mean per bacterium. *Statistically significant response (P<0.05); **highly statistically significant response (P<0.01) using Student’s t test.