Formation of multiple treponemes.

The formation of pseudomulticellular treponemes was analyzed using different electron microscopical methods such as thin sectioning, freeze fracturing and scanning electron microscopy. The development of spherical bodies is preceded by the formation of unseparated helical forms and plait-like structures. During this process, the bacteria lose their individual outer sheath as well as their axial flagella and produce a common outer envelope. The possible pathogenetic importance of such multiple structures is discussed.