Total number of dented spot observed on cell surface.

<p>The dented spots on both the trunk and tips were counted in 50 cells of <i>B. subtilis</i> (<b>diamond</b>) and <i>E. coli</i> (<b>circle</b>) from cultures with (<b>a</b>) different chlorhexidine concentrations for 6 hr and (<b>b</b>) treated with 0.75 mg/L of chlorhexidine for different lengths of time. These results were confirmed in two independent experiments.