Motility assay.

<p><i>T</i>. <i>denticola</i> strains were seeded on a medium containing 0.5% agar. After the plate was anaerobically incubated at 37°C for one week, the turbid plaque was measured. Each plate presented is a representative image. The data are expressed as the means ± SD (n = 3). A Dunnett’s test was performed to compare the wild type and mutants (**, <i>P</i><0.01).