The Family <i>Borreliaceae</i> (Spirochaetales), a Diverse Group in Two Genera of Tick-Borne Spirochetes of Mammals, Birds, and Reptiles

Abstract Spirochetes of the family Borreliaceae are, with one exception, tick-borne pathogens a variety vertebrates. The at present comprises two genera: Borrelia (Swellengrebel), which includes agents relapsing fever, avian spirochetosis, and bovine borreliosis, Borreliella (Gupta et al.), Lyme disease was formerly known as ‘Borrelia burgdorferi sensulato complex’. genera are distinguished not only by their associations but also biological features in tick vector, including tissue location unfed ticks transovarial transmission. species transmitted argasid (soft) tend to have more exclusive relationships vectors than do other all that ixodid (hard) vectors. division is supported phylogenomic evidence from whole genomes several specific molecular markers. These distinguishing phylogenetic criteria applied three new or isolates were discovered reptiles, monotreme, birds. Although deep branching spirochetes has been challenge for inferences about evolution family, discovery related microorganisms gut microbiota arachnids suggests an ancestral origin symbionts arachnids.