Temperature-dependent Motility in <i>H. pylori</i>

Helicobacter pylori employ a run-reversal strategy in contrast to the run-tumble strategy employed by E. coli during navigation. As a result, their migration patterns are anticipated to be different from those in E. coli. We have quantitatively determined the effect of medium temperatures on the two modes of H. pylori motility – a pusher mode in which the flagella lag behind the body and a puller mode in which the flagella precede the body. Our data show that the cells swam faster in one mode relative to another as a function of temperature. The mean durations of the runs in either mode also depended on the temperature, as did the fraction of the time that the flagellar filaments rotated counterclockwise. We analyzed the mean squared displacements of the cell populations and determined that the bacterial spread was the highest at temperatures close to physiological temperatures. We will present a quantitative model that accounts for the anisotropic random walk to predict the temperature dependence of the bacterial diffusion. The fundamental insights from this work are likely to provide a handle for determining the motile responses of H. pylori to various types of environmental stressors.