The genus Borrelia, in the spirochete phylum, is not closely related to any other bacteria and has a highly unusual genome composed of a linear chromosome and multiple circular and linear plasmids that appear to be in a constant state of rearrangement, recombination, and deletion. The determination of the genome sequence of Borrelia strains has facilitated tremendous advances in understanding this genus at the molecular and cellular level, as well as the pathogenesis of Lyme disease and relapsing fever. In recent years, there has been an explosion of new insights into the molecular biology, genetics, physiology, and ecology of Borrelia and its tick/vertebrate life cycle. This research is of particular importance as the incidence of Lyme borreliosis continues to increase. Written by renowned scientists who have made seminal contributions to the field, this book is a comprehensive guide to the pathogenic Borrelia, providing researchers, advanced students, clinicians, and other profession