Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2007 Mar;13(3):436-42.
doi: 10.3201/eid1303.060958.

Diversity and distribution of Borrelia hermsii

Tom G Schwan  1 , Sandra J Raffel, Merry E Schrumpf, Stephen F Porcella
Affiliations

Diversity and distribution of Borrelia hermsii

Tom G Schwan et al. Emerg Infect Dis. 2007 Mar.

Abstract

Borrelia hermsii is the most common cause of tickborne relapsing fever in North America. DNA sequences of the 16S-23S rDNA noncoding intergenic spacer (IGS) region were determined for 37 isolates of this spirochete. These sequences distinguished the 2 genomic groups of B. hermsii identified previously with other loci. Multiple IGS genotypes were identified among isolates from an island, which suggested that birds might play a role in dispersing these spirochetes in nature. In support of this theory, all stages of the tick vector Ornithodoros hermsi fed successfully on birds in the laboratory and advanced in their life cycle. B. hermsii produced a detectable spirochetemia in 1 chicken inoculated subcutaneously. Additional work is warranted to explore the role of birds as enzootic hosts for this relapsing fever spirochete.

PubMed Disclaimer

Figures

Figure 1
Figure 1
Western United States showing the approximate endemic range of tickborne relapsing fever associated with Ornithodoros hermsi and the localities of origin for the 37 Borrelia hermsii isolates included in this study. Genome group I (GGI) isolates are shown by open circle; GGII isolates are shown by filled circle. Localities of 6 isolates discussed in detail are indicated with arrows.
Figure 2
Figure 2
Phylogram of the intergenic spacer sequences of 37 Borrelia hermsii isolates. The tree was constructed with ClustalV and the neighbor-joining method with 1,000 bootstrap replicates. Numbers at the nodes are the percentages of bootstraps that supported this pattern. The scale bar for the branch lengths represents the number of substitutions per site. An unrooted tree is shown because a gap in the alignment with B. turicatae resulted in the removal of a polymorphic site in some GGII isolates of B. hermsii.
See this image and copyright information in PMC

References

    1. Dworkin MS, Schwan TG, Anderson DE. Tick-borne relapsing fever in North America. Med Clin North Am. 2002;86:417–33. 10.1016/S0025-7125(03)00095-6 - DOI - PubMed
    1. Davis GE. Species unity or plurality of the relapsing fever spirochetes. In: Moulton FR, editor. A symposium on relapsing fever in the Americas. Washington: American Association for the Advancement of Science;1942. p. 41–7.
    1. Kelly R. Cultivation of Borrelia hermsi. Science. 1971;173:443–4. 10.1126/science.173.3995.443 - DOI - PubMed
    1. Porcella SF, Raffel SJ, Anderson DE Jr, Gilk SD, Bono JL, Schrumpf ME, et al. Variable tick protein in two genomic groups of the relapsing fever spirochete Borrelia hermsii in western North America. Infect Immun. 2005;73:6647–58. 10.1128/IAI.73.10.6647-6658.2005 - DOI - PMC - PubMed
    1. Schwan TG, Raffel SJ, Schrumpf ME, Policastro PF, Rawlings JA, Lane RS, et al. Phylogenetic analysis of the spirochetes Borrelia parkeri and Borrelia turicatae and the potential for tick-borne relasping fever in Florida. J Clin Microbiol. 2005;43:3851–9. 10.1128/JCM.43.8.3851-3859.2005 - DOI - PMC - PubMed

Publication types

MeSH terms

LinkOut - more resources