Genomic Confirmation of Borrelia garinii, United States

Abstract

Lyme disease is a multisystem disorder primarily caused by Borrelia burgdorferi sensu lato. However, B. garinii, which has been identified on islands off the coast of Newfoundland and Labrador, Canada, is a cause of Lyme disease in Eurasia. We report isolation and whole-genome nucleotide sequencing of a B. garinii isolate from a cotton mouse (Peromyscus gossypinus) in South Carolina, USA. We identified a second B. garinii isolate from the same repository. Phylogenetic analysis does not associate these isolates with the previously described isolates of B. garinii from Canada.

Keywords: Borrelia garinii; Lyme disease; United States; bacteria; genomic conformation; migrating hosts; rodents; vector-borne infections; zoonoses.

Figure

Maximum-likelihood phylogeny of Borrelia garinii/B. bavariensis. A) Maximum-likelihood phylogeny of B. garinii/B. bavariensis rooted with B. turdi. Topology is based on analysis of the partitioned dataset of 8 multilocus sequence typing genotyping loci s) under the generalized time reversible plus Γ4 model (for each partition) in RAxML 8 (https://cme.h-its.org/exelixis/web/software/raxml). The final alignment comprises 184 taxa and 4,791-nt positions. Thickened branches indicate branching support as estimated by nonparametric bootstrap analysis based on 1,000 replicates in RAxML 8. For better readability, support is categorized according to the scheme shown at the bottom of the tree. Isolates were clustered into 7 categories according to their geographic origin, which is color-coded according the scheme in the upper right part of the tree on the topology. The position of 2 US isolates is indicated by an asterisk. B) Subset of results phylogeographic analysis of diffusion on the discrete space showing the estimated geographic origin of the inner branches for the ancestral clade of B. garinii from Asia. Full topology is shown in Appendix Figure 2, panel B, and full details on the methods used are provided in the Appendix. Scale bars indicate nucleotide substitutions per site. BS, branching support.