Typing African Relapsing Fever Spirochetes

Scott, Julie C.; Wright, David J.; Cutler, Sally J.

doi:10.3201/eid1111.050483

Cited by 45 publications

(88 citation statements)

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“…The results with flaB have shown only minor differences among relapsing fever Borrelia species. On the other hand, although the intergenic spacer rrs-rrl is not able to discriminate between B. recurrentis and B. duttonii (29), it has been shown to discriminate between strains of other RF Borrelia species.…”

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confidence: 98%

Phylogenetic Analysis of a Virulent Borrelia Species Isolated from Patients with Relapsing Fever

et al. 2010

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Multilocus sequence analysis (MLSA) was used to clarify the taxonomic status of a virulent Borrelia organism previously isolated from patients with relapsing fever and from ticks in Spain that is designated the Spanish relapsing fever (SRF) Borrelia. This species has been used extensively in experimental infection models because of its continued virulence. Seven genes were amplified to analyze the phylogenetic relationships among several Spanish isolates of SRF Borrelia and other relapsing fever Borrelia species. The genes targeted in this study included rrs and flaB, which have commonly been used in phylogenetic studies; the rrf-rrl intergenic spacer (IGS), which is highly discriminatory; and four additional genes, p66, groEL, glpQ, and recC, which are located on the chromosome and which have therefore evolved in a clonal way. The species included in this study were Borrelia duttonii, B. recurrentis, B. crocidurae, and B. hispanica as Old World Borrelia species and B. turicatae and B. hermsii as New World Borrelia species. The results obtained by MLSA of the SRF Borrelia on the basis of 1% of the genomic sequence data analyzed confirmed that the SRF Borrelia isolates are B. hispanica. However, the prototype isolates of B. hispanica used in this study have an uncertain history and display unique phenotypic characteristics that are not shared with the SRF Borrelia. Therefore, we propose to use strain SP1, isolated from a relapsing fever patient in 1994 in southern Spain, as the type strain for B. hispanica.The members of the Borrelia genus comprise two major groups: those causing Lyme disease and those causing relapsing fever (RF). Relapsing fever is distributed all over the world; and its agents are traditionally classified according to their geographic origins, vector, and infectivity in various animal species. In Spain, relapsing fever has been reported sporadically throughout the last century and has been associated with Borrelia hispanica (2,11,17,19,27,28). From 1994 to 1996, spirochetes were isolated from the blood of two patients with RF symptoms and from Ornithodoros erraticus, and we have designated these spirochetes Spanish relapsing fever (SRF) Borrelia. This SRF organism is refractory to in vitro cultivation, and this represents a unique phenotypic characteristic not shared by B. hispanica (1). SRF Borrelia infects C3H/ HeN, BALB/c, C57/B51, and Swiss outbred mice (1), and it is highly infectious. A murine model of SRF was developed (13) and has been used extensively in experimental studies on pathogenesis and the host response (5-7, 14, 16, 20). A preliminary genetic analysis comparing the rrs and flaB loci from B. hispanica to those from the Spanish isolates suggested that SRF could represent a new species (1).To date, most of the ecological and epidemiological studies on relapsing fever Borrelia have used a single locus. Therefore, characterization of relapsing fever spirochetes has relied upon the amplification and sequencing of certain genes, such as rrs (24), flaB (12), and more recently, the n...

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confidence: 98%

Phylogenetic Analysis of a Virulent Borrelia Species Isolated from Patients with Relapsing Fever

et al. 2010

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“…Concatenated coding genes can be used to draw phylogenetic inference, while IGS, being noncoding, provides a more discriminatory typing tool. Our findings revealed a high degree of homology between B. microti and isolates of B. duttonii and B. recurrentis, while typing of IGS proved to be more discriminatory than typing of other loci but could show overlap between subgroups of B. duttonii and B. recurrentis (7,25,28). The greatest nucleotide homology between B. microti and B. duttonii over the loci analyzed ( Fig.…”

Section: Discussionmentioning

confidence: 59%

“…Again, this might parallel the milder TBRF seen to be associated with B. crocidurae infection in West Africa (5). Borrelia duttonii isolates Bd9, Bd11, and WM were from spirochetemic febrile patients, and strain TzBd1was from an asymptomatic blood donor in Tanzania (7,25). Whether the difference in virulence is due to adaptation to different tick vectors is open to question; this can be assessed following cross-vector exchanges of spirochetes derived from O. erraticus and O. moubata.…”

Section: Discussionmentioning

confidence: 99%

Phylogenetic Analysis of the Spirochete Borrelia microti, a Potential Agent of Relapsing Fever in Iran

et al. 2012

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We report a role for Borrelia microti as a cause of relapsing fever in Iran supported by robust epidemiological evidence. The molecular identity of this spirochete and its relation with other relapsing fever borreliae have, until now, been poorly delineated. We analyzed an isolate of B. microti , obtained from Ornithodoros erraticus ticks, by sequencing four loci (16S rRNA, flaB , glpQ , intragenic spacer [IGS]) and comparing these sequences with those of other relapsing fever borreliae. Phylogenetic analysis using concatenated sequences of 16S rRNA, flaB , and glpQ grouped B. microti alongside three members of the African group, B. duttonii , B. recurrentis , and B. crocidurae , which are distinct from B. persica , the most prevalent established cause of tick-borne relapsing fever in Iran. The similarity values for 10 concatenated sequences totaling 2,437 nucleotides ranged from 92.11% to 99.84%, with the highest homologies being between B. duttonii and B. microti and between B. duttonii and B. recurrentis . Furthermore, the more discriminatory IGS sequence analysis corroborated the close similarity (97.76% to 99.56%) between B. microti and B. duttonii . These findings raise the possibility that both species may indeed be the same and further dispel the one-species, one-vector theory that has been the basis for classification of relapsing fever Borrelia for the last 100 years.

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“…The impact of TBRF is most strongly felt in Africa. In regions of Tanzania, Sudan, and Ethiopia, TBRF is among the top 10 killers of children under the age of 5 years, and nearly 40% of children under the age of 1 year will develop the disease (13,14,56).…”

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confidence: 99%

Identification of an Antiparallel Coiled-Coil/Loop Domain Required for Ligand Binding by theBorrelia hermsiiFhbA Protein: Additional Evidence for the Role of FhbA in the Host-Pathogen Interaction

Hovis¹,

Freedman²,

Zhang³

et al. 2008

Infect Immun

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Typing African Relapsing Fever Spirochetes

Abstract: Sequencing distinguished relapsing fever from other borrelial species but not B. duttonii from B. recurrentis.

Cited by 45 publications

References 30 publications

Phylogenetic Analysis of a Virulent Borrelia Species Isolated from Patients with Relapsing Fever

Phylogenetic Analysis of a Virulent Borrelia Species Isolated from Patients with Relapsing Fever

Phylogenetic Analysis of the Spirochete Borrelia microti, a Potential Agent of Relapsing Fever in Iran

Identification of an Antiparallel Coiled-Coil/Loop Domain Required for Ligand Binding by theBorrelia hermsiiFhbA Protein: Additional Evidence for the Role of FhbA in the Host-Pathogen Interaction

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