from Paphavee Lertsethtakarn, Jenny Draper and Karen M. Ottemann writing in Two-Component Systems in Bacteria:
The gastric pathogenic bacterium Helicobacter pylori has a relatively simple chemotaxis system, with four chemoreceptors plus a set of signal transduction proteins consisting of the CheA kinase, CheW and CheV coupling proteins, a CheY response regulator, the CheZ phosphatase and an unusual protein termed ChePep. H. pylori chemotaxis response has proved challenging to study, but studies have established that H. pylori uses its chemotaxis system to move away from low pH and autoinducer-2, and to respond to cellular energy status along with several chemicals . During stomach infection, H. pylori chemotaxis plays multiple roles including promoting early infection and critical epithelial interactions that drive a wild-type immune response.
Further reading: Two-Component Systems in Bacteria