Controversies in bacterial taxonomy: The example of the genus Borrelia

In this paper we survey key issues in bacterial taxonomy and review the literature regarding the recent genus separation proposed for the genus Borrelia. We discuss how information on members of the genus Borrelia is increasing but detailed knowledge on the relevant features is available only for a small subset of species. The data accumulated here show that there is considerable overlap in ecology, clinical aspects and molecular features between clades that argue against splitting of the genus Borrelia.