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.
Highlights
EM* EM EM EM EM EM/multiple Lymphom Lymphom NB§ NB NB NB NB Skin/chest Skin/knee N/A - Tick isolate
We included in our analyses 17 genome sequences that are publicly available (Table 2); most of them are from the USA (n = 14) while three are from Europe (Bol[26], SV1, and ZS7) and the closely related species B. bissettii strain DN127 was used as an outgroup
We found 92 locally colinear blocks (LCBs), eight of them contain DNA conserved in all the strains and were used for downstream analysis; these eight LCBs are described in Supplementary Table 2
Summary
EM* EM EM EM EM EM/multiple Lymphom Lymphom NB§ NB NB NB NB Skin/chest Skin/knee N/A - Tick isolate. Determines the geographic distribution of the bacteria (and the disease) to the temperate zones of the northern hemisphere (roughly from latitude 40 degree - 60 degree N). Within this geographic range of vector and host occurrence, the distribution of Borrelia species is not uniform. We exploit the high resolution of NGS to obtain a better understanding of the relatedness of populations from Europe and the USA, with a particular view on human patient isolates from Europe, and to re-address the question of the origin of B. burgdorferi s.s. We included in our analysis some previously sequenced strains to create a more comprehensive data set for this species in terms of genome sequences and geographic origin
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
