Molecular identification of Borrelia crocidurae in a patient returning from Senegal

“…B. duttonii has been documented in Tanzania and B. recurrentis in Ethiopia [5], [6], [7], [8]. Relapsing fevers are of further concern in travelers returning from Africa in Europe [9], [10], [11].…”

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confidence: 99%

Multiplex Real-Time PCR Diagnostic of Relapsing Fevers in Africa

et al. 2013

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BackgroundIn Africa, relapsing fever borreliae are neglected arthropod-borne pathogens causing mild to deadly septicemia and miscarriage. The closely related Borrelia crocidurae, Borrelia duttonii, Borrelia recurrentis and Borrelia hispanica are rarely diagnosed at the species level, hampering refined epidemiological and clinical knowledge of the relapsing fevers. It would be hugely beneficial to have simultaneous detection and identification of Borrelia to species level directly from clinical samples.Methodology/Principal FindingsWe designed a multiplex real-time PCR protocol targeting the 16S rRNA gene detecting all four Borrelia, the glpQ gene specifically detecting B. crocidurae, the recN gene specifically detecting B. duttonii/B. recurrentis and the recC gene specifically detecting B. hispanica. Compared to combined 16S rRNA gene and flaB gene sequencing as the gold standard, multiplex real-time PCR analyses of 171 Borrelia-positive and 101 Borrelia-negative control blood specimens yielded 100% sensitivity and specificity for B. duttonii/B. recurrentis and B. hispanica and 99% sensitivity and specificity for B. crocidurae.Conclusions/SignificanceThe multiplex real-time PCR developed in this study is a rapid technique for both molecular detection and speciation of relapsing fever borreliae from blood in Africa. It could be incorporated in point-of-care laboratory to confirm diagnosis and provide evidence of the burden of infection attributed to different species of known or potentially novel relapsing fever borreliae.

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“…Relapsing fever mimics malaria, with which relapsing fever is often confused in the absence of laboratory confirmation (7). B. crocidurae remains a neglected organism that is rarely investigated using nonspecific laboratory tools.…”

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confidence: 99%

Complete Genome Sequence of Borrelia crocidurae

et al. 2012

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cWe announce the draft genome sequence of Borrelia crocidurae (strain Achema). The 1,557,560-bp genome (27% GC content) comprises one 919,477-bp linear chromosome and 638,083-bp plasmids that together carry 1,472 open reading frames, 32 tRNAs, and three complete rRNAs, with almost complete colinearity between B. crocidurae and Borrelia duttonii chromosomes. Borrelia crocidurae is a spirochete responsible for tick-borne zoonotic relapsing fever in West Africa, where the soft tick Ornithodoros sonrai is the vector (2, 12). Relapsing fever mimics malaria, with which relapsing fever is often confused in the absence of laboratory confirmation (7). B. crocidurae remains a neglected organism that is rarely investigated using nonspecific laboratory tools.The B. crocidurae Achema strain (11), grown in BarbourStoenner-Kelly H medium (Sigma, Saint-Quentin-Fallavier, France) supplemented with 6% rabbit serum (Eurobio, Courtaboeuf, France) at 33°C, was sequenced using pyrosequencing technology on a Roche 454 GS FLX sequencer (Roche, BoulogneBillancourt, France). An average 24-fold genomic coverage was obtained over 22,610 paired-end reads, which were assembled using the Newbler 2.3 assembler (Roche), generating 41 scaffolds. Ordering, using the Borrelia duttonii genome (5) as a reference, left 39 plasmid scaffolds in draft status, whereas 2 chromosome scaffolds were closed by PCR sequencing. An in-house pipeline based on the Prodigal program was used to annotate the DNA sequences (3). tRNAs were predicted using the Aragorn program (4), and rRNAs were predicted using RNAmmer. The functional annotation of predicted genes was performed using RPS-BLAST (6) against Pfam (9) and the Cluster of Orthologous Groups (COG) database (10). We performed BLASTP analysis of B. duttonii open reading frames (ORFs) versus the B. crocidurae chromosome (1), and codon usage was determined using the E-CAI server (8).The 1,557,560-bp linear B. crocidurae genome (27% GC content) carries 1,472 ORFs, 32 tRNAs, and three complete rRNAs. The 919,477-bp chromosome carries 865 ORFs, of which 79% are proteins listed in the COG database. The S200-like transposase and transposase IS605 OrfB in B. crocidurae disrupt the almost complete colinearity between B. crocidurae, B. duttonii, and B. recurrentis chromosomes. Seven copies of these elements are found in the B. duttonii plasmid complement, and six copies are found in the Borrelia recurrentis plasmid complement. Additionally, a 5-kbp B. duttonii duplication encoding an RNA pseudouridylate synthase family protein, MurC, and the hypothetical proteins BDU_828 and BDU_830 is absent from the B. crocidurae chromosome. Comparing B. crocidurae with B. duttonii revealed 771 orthologs with an average pairwise amino acid sequence identity of 95 to 100% and identical codon usage. Unlike B. recurrentis, B. crocidurae has intact recA, mutS, and smf genes (5). The exact number of plasmids remained undetermined due to repeat sequences and size overlap, but 607 ORFs, including a telomerase resolvase, are conserved among the...

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Molecular identification of Borrelia crocidurae in a patient returning from Senegal

Cited by 10 publications

References 19 publications

Tick-Borne Relapsing Fever Borreliosis, Rural Senegal

Tick-Borne Relapsing Fever Borreliosis, Rural Senegal

Multiplex Real-Time PCR Diagnostic of Relapsing Fevers in Africa

Complete Genome Sequence of Borrelia crocidurae

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