FIG. 1.

AI-2 production in H. pylori is luxS dependent. AI-2 production in the wild-type strain G27 (A), the ΔluxS mutant (B), and the complemented luxS* strain (C) was measured as the ability of CFS harvested at the indicated times after inoculation of liquid H. pylori cultures to induce bioluminescence in the V. harveyi reporter strain BB170 (relative light units [RLU]; bars). The cell densities of the cultures across the growth curves were determined by viable plate counts (CFU/ml; diamonds). Error bars indicate standard deviations of triplicate or duplicate samples for the bioluminescence and cell density measurements, respectively.