title: Trans-Atlantic exchanges have shaped the population structure of the Lyme disease agent Borrelia burgdorferi sensu stricto.
abstract: The origin and population structure of Borrelia burgdorferi sensu stricto (s.s.), the agent of Lyme disease, remain obscure. This tick-transmitted bacterial species occurs in both North America and Europe. We sequenced 17 European isolates (representing the most frequently found sequence types in Europe) and compared these with 17 North American strains. We show that trans-Atlantic exchanges have occurred in the evolutionary history of this species and that a European origin of B. burgdorferi s.s. is marginally more likely than a USA origin. The data further suggest that some European human patients may have acquired their infection in North America. We found three distinct genetically differentiated groups: i) the outgroup species Borrelia bissettii, ii) two divergent strains from Europe, and iii) a group composed of strains from both the USA and Europe. Phylogenetic analysis indicated that different genotypes were likely to have been introduced several times into the same area. Our results demonstrate that irrespective of whether B. burgdorferi s.s. originated in Europe or the USA, later trans-Atlantic exchange(s) have occurred and have shaped the population structure of this genospecies. This study clearly shows the utility of next generation sequencing to obtain a better understanding of the phylogeography of this bacterial species.
authors.affiliation: Programa de Genómica Evolutiva, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Apartado Postal 565-A, CP 62210, Cuernavaca, Morelos, México.
authors.forename: S
authors.initials: S
authors.lastname: Castillo-Ramírez
authors.affiliation: National Reference Center for Borreliosis at the Bavarian Health and Food Safety Authority, Veterinärstr. 2, 85764 Oberschleissheim, Germany.
authors.forename: V
authors.initials: V
authors.lastname: Fingerle
authors.affiliation: National Reference Center for Borreliosis at the Bavarian Health and Food Safety Authority, Veterinärstr. 2, 85764 Oberschleissheim, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Jungnick
authors.affiliation: LMU Munich, Department of Infection and Zoonoses, Veterinärstr. 13, 80539 Munich, Germany.
authors.forename: R K
authors.initials: RK
authors.lastname: Straubinger
authors.affiliation: LMU Munich, Gene Centre, Lafuga, Feodor-Lynen-Strasse 25, 81377 Munich, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Krebs
authors.affiliation: LMU Munich, Gene Centre, Lafuga, Feodor-Lynen-Strasse 25, 81377 Munich, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Blum
authors.affiliation: National Reference Center for Borreliosis at the Bavarian Health and Food Safety Authority, Veterinärstr. 2, 85764 Oberschleissheim, Germany.
authors.forename: D M
authors.initials: DM
authors.lastname: Meinel
authors.affiliation: TU Munich, Klinik für Dermatologie and Allergologie, 80802 Munich, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Hofmann
authors.affiliation: National Reference Center for Borreliosis at the Bavarian Health and Food Safety Authority, Veterinärstr. 2, 85764 Oberschleissheim, Germany.
authors.forename: P
authors.initials: P
authors.lastname: Guertler
authors.affiliation: National Reference Center for Borreliosis at the Bavarian Health and Food Safety Authority, Veterinärstr. 2, 85764 Oberschleissheim, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Sing
authors.affiliation: National Reference Center for Borreliosis at the Bavarian Health and Food Safety Authority, Veterinärstr. 2, 85764 Oberschleissheim, Germany.
authors.forename: G
authors.initials: G
authors.lastname: Margos
mesh_terms: D025065:Borrelia burgdorferi / Q000145:classification* / Q000235:genetics*; D005060:Europe / Q000453:epidemiology; D019143:Evolution, Molecular; D014644:Genetic Variation; D059014:High-Throughput Nucleotide Sequencing; D006801:Humans; D008193:Lyme Disease / Q000453:epidemiology* / Q000382:microbiology*; D017720:Molecular Epidemiology; D010802:Phylogeny; D017422:Sequence Analysis, DNA; D014481:United States / Q000453:epidemiology