[Incidence and significance of treponemes in animals].

The genus Treponema consists of various species. Currently most of them are not cultivable because respective cultivation conditions are unknown. Therefore the biodiversity of treponemes was only appreciated recently by applying comparative 16S rRNA sequence analysis. Treponemes are mainly representatives of the gastrointestinal autochthonal flora, especially in termites, but they have also been described in swine and cattle. On the other hand treponemes are involved in different infectious diseases, the most well known being syphilis in humans or venereal spirochetosis in rabbits. Furthermore, treponemes are associated with several infectious periodontal diseases, e.g. gingivitis or periodontitis, where they can be detected regularly. Culture has not been successful for most of the oral treponemes, so the major part can only be identified by their 16S rRNA sequence. Similar to these oral disorders treponemes are also associated with digital dermatitis (DD), a chronic inflammatory disease of the bovine skin, where different treponemal phylotypes were found in large numbers. Treponema brennaborense was first identified and isolated in DD biopsies. Unravelling the pathogenic potential and aetiological significance of treponemes in chronic infectious diseases like peridontitis or DD remains a costly task. Although treponemes can be frequently detected in such lesions, it is often unclear to what extent treponemes are involved in pathogenesis of these diseases. The possession of various virulence features like high motility, the ability to adhere and invade as well as to cause cytopathic effects in eukaryotic cells are highly indicative of the aetiological relevance of treponemes.