Fig. 5.

H. pylori responds to zinc as an attractant and nickel as a repellent. (a) H. pylori in Brucella broth/2.5 % FBS soft agar supplemented with 50–250 µM ZnCl₂. (b) Same as (a), but with NiCl₂ supplementation. (c) Same as (b), but comparing H. pylori SS1 wild-type with isogenic single chemoreceptor mutants. Migration distances are the means of two to four biological replicates, which included seven to eight technical replicates each. Error bars, sem. Both distances and errors were normalized to the wild-type 0 µM sample by dividing by the distance for that sample. *P<0.05 using Student’s t test on the non-normalized data. (d) Image of H. pylori colonies on unsupplemented and zinc-supplemented soft agar plates.