FIG 3 .

Effects of nickel supplementation on the transcription of ureA in WT H. pylori 26695 or Δmua, ΔnikR, or Δmua ΔnikR mutants. The levels of ureA transcripts were quantified after 24 h of growth on BA medium supplemented with 0, 5, or 50 µM NiCl₂. The relative abundance of each transcript was calculated with the 2^−ΔCT formula and using the gyrA gene (hp0701) as a housekeeping gene control. Results are the mean and standard deviation of assays performed in triplicate. The error bars shown represent 2^−ΔCT – 2^{−[ΔCT + SD]} and 2^{−[ΔCT − SD]} – 2^−ΔCT.