EVIDENCE FOR 2 DISTINCT LOCOMOTORY PHENOTYPES OF TREPONEMA-DENTICOLA ATCC-35405

Using a two-layer system, a bottom layer containing treponema cells su spended in NOS (New Oral Spirochete)-Noble agar medium or NOS-Bacto ag ar medium and overlaid with cell-free NOS-agarose medium resulted in t he spirochete cells migrating into the top layer. However, if the posi tions of the medium layers were reversed with the cells inoculated int o the bottom layer containing NOS-agarose, there was no migration into the upper layer. This suggests migration of the spirochetes away from Bacto and Noble agars. Using a 3-layer system in which cells were ino culated into a middle layer consisting of NOS-agarose medium and sandw iched between cell-free NOS-agarose medium layers, cells remained with in the middle layer. If the cells were inoculated into a middle layer consisting of NOS-Bacto agar medium while the upper and lower layers r emained unchanged, cells migrated into both upper and lower layers. If cells that had migrated into the upper layer were transferred into a middle layer, they virtually all migrated into the upper layer repeate dly. Cells that had migrated into the lower layer and transferred to t he middle layer migrated repeatedly into the lower layer. These result s suggest the possible existence of two distinct locomotory phenotypes within this strain of treponeme.