Genome size of human oral Treponema species by pulsed-field gel electrophoresis.

The genome sizes of seven strains of oral treponemes were determined using pulsed-field gel electrophoresis (PFGE). These strains represent members from six of the currently known cultivable oral treponeme groups. The PFGE fragments were digitally recorded and then quantitated using GIMP v 1.2, an image manipulation program. The results show that the six oral treponeme genomes are comparable in size, ranging from approximately 2.2 to 2.5 Mbp. The genome sizes of these strains are 20-25% smaller than Treponema denticola strains, which have genome sizes of approximately 2.8-3.0 Mbp.