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Sequencing of Treponema pallidum ssp. pertenue Samoa D genome

Abstract number: 1733_412

Matejkova P., Strouhal M., [Scaron]majs D., Norris S.J., Weinstock G.M.

Objectives:Treponema pallidum ssp. pertenue (TPE) causes endemic treponematosis yaws. Genome of this pathogen was shown to be 99% identical to Treponema pallidum ssp. pallidum (TPA), the causative agent of syphilis. Although syphilis and yaws have different clinical manifestation, the pathogens are microscopically and serologically indistinguishable. Genome scale approaches (microarray hybridisations and whole genome fingerprinting – WGF) showed that there are no gene deletions and multiplications and no large indels. Relatively subtle genetic differences responsible for different pathogenesis of syphilis and yaws thus require complete genome sequence of TPE.

Methods: Comparative genome sequencing (CGS) is a technique based on hybridisation of the test and the reference genomic DNA to the oligonucleotide chip and has two stages. In the first stage, heterologous regions of the test genome were mapped and in the second step, positions of single nucleotide polymorfisms (SNPs) in the test genome were revealed. Additional regions containing clustered SNPs and indels were subjected to dideoxyterminator (DDT) sequencing. Physical map of complete genome sequence obtained by combination of CGS and DDT of heterologous regions was confirmed by WGF.

Results: CGS together with DDT sequencing and WGF was employed to obtain complete genome sequence of TPE Samoa D strain. The unfinished complete genome sequence comprised 1 linear contig. CGS revealed 904 SNPs and 84 regions were suggested for DDT sequencing. DDT sequencing of these regions revealed more than additional 500 SNPs and 85 indels in the length range of 1 303 bp. WGF was used to verify the assembly of the genomic sequence and to conclude the exact number of repeats in 2 tandem repeat regions and in additional 4 regions comprising T. pallidum repeat (tpr) genes and hypothetical genes in their vicinity. In silico proteome analysis revealed that more than 300 proteins (out of 1039 proteins predicted in TPA Nichols strain) were affected by sequence changes.

Conclusion: The genome sequence of yaws treponeme was used to define intersubspecies difference between TPE and TPA.

This work was supported by the grants from the Internal Grant Agency of the Ministry of Health of the Czech Republic (NR/8967–4/2006) and from the Grant Agency of the Czech Republic (310/04/0021).

Session Details

Date: 31/03/2007
Time: 00:00-00:00
Session name: European Society of Clinical Microbiology and Infectious Diseases
Subject:
Location: ICC, Munich, Germany
Presentation type:
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